Insights from Coffee Roasting Presentation

Hola, hola, hola, hola, hola. Está funcionando? Is it working? Debo presentar en español mejor? Lo siento, que no. El próximo año voy a hacer en español, pero this year I'll do it in English. Um, yeah. I am... here today to talk about coffee roasting the name of my talk is roasting isn't that hard how many roasters are here raise your hand let me see yeah yeah yeah yeah yeah uh yeah uh so roasting isn't that hard, it's also not that easy. So I want to talk about the difficult and not so difficult parts of roasting. Really I want to demystify, break down, simplify the parts of roasting that I think a lot of us roasters, maybe even baristas or consumers, have a hard time understanding so that we can all feel a little bit more comfortable or a little bit more confident approaching roasting. So yeah. Roasting isn't that hard. People have been roasting coffee for centuries, literally, without the use of modern technology, without roasting software, though thanks Cropster for sponsoring this event, and without... the use of cupping forms. People have been turning coffee brown. So with the skills and with the tools available to us today, if you understand a few core concepts and master a few key skills, you can roast coffee with confidence, with ease, and with consistency. As I said, and as we all know, roasting also isn't that easy. The world of roasting is full of complicated concepts and contrasting opinions about what makes a good coffee roast, what makes a bad coffee roast. And there's a lot of technical jargon to sort through. So it takes time to learn these concepts, to understand these ideas, to get comfortable with green coffee, with machines, and with tasting coffee, with understanding the effect that roasting has on green coffee. So, not to mention, as we all know, both as baristas, consumers, roasters, every coffee is different. Every machine is different. What works for one might not work for another. This is our job, this is our work to develop these skills. So, as coffee roasters, how are we to maintain quality, consistency in our day-to-day jobs? I'm Kat Malheim. Hello. Some of you may know me as RoasterKat on Instagram and YouTube. And I've been posting on educational things on Instagram pretty much for the seven years since I started learning how to roast. mostly because I was entering the world of roasting and I didn't see other educational tools out there. There was maybe one or two books, a couple of blogs, but outside of attending expensive events or... master classes, it was really hard to find information. So as I started learning, I pretty much started posting on Instagram the things I was learning, mostly to remember myself, but also to share with people who didn't have access to those same rooms that I was able to be in and those classes I was able to take. So today I'm going to talk about the easy and hard parts of being a coffee roaster and we're going to break down some key concepts, highlight what I have found to be critical parts of roasting coffee, and then we're going to demystify the roasting process of it. This will also include some actionable tips, tricks, and exercises, so get your phones out and be ready to take pictures and then go back to your own roasteries and try out some of these things. So let's go. Are you ready? All right, there are different definitions of coffee roasting, but really essentially, coffee roasting is applying heat to raw coffee beans to create a series of physical and chemical changes within the coffee beans. Another way to put it is, Turning coffee brown by making it hot. See? It's simple. But the difficult part is doing this in a controlled way and doing it in a way that we can replicate so that we have consistency. I know, you know, this sounds easy, but we've all, I mean, maybe it's just me, but as roasters, haven't we all gone a little too short? We end up with grassy and harsh notes that really take out the acidity, or we go a little too far with the coffee, and we end up with burnt and roasty notes, and they overpower the sweetness. So our work is finding that middle bit and then doing it over. So to get on the same page, we're going to go over some of these physical and chemical changes that happen during coffee roasting. So the physical changes, basic definition, are the visible characteristics of coffee seed change, the things we can see, the things we can notice. Obviously, coffee changes color. We all have seen that. That's part of my definition. and turning coffee brown. So coffee goes from a greenish, well, we call it green coffee, greenish, bluish, tannish color to a range of browns. Also, coffee's... Seed size increases 20 to 50 percent depending on the heat application depending on the variety of coffee that you're roasting We have mass decrease. So the coffee even though it gets bigger It loses weight in the roasting process part of that is moisture water Water is released from the beans during roasting because you're putting heat on it. It evaporates and We go from about 10 to 12 percent, which is usually ideal for specialty coffee, to about 2.5 percent in roasted coffee. The coffee also increases in brittleness and porosity. This allows us to grind and brew the coffee, which is kind of the point of the whole thing. The cells swell due to this heat application. They become harder, and then when we put it through a grinder, they break up. If you go dark enough, oils migrate to the surface. Another thing we can see. Most of the time in specialty, we don't go that far, but sometimes you do. And if that's what you intended to do, great. Then we have the chemical changes. This one is a lot of words. So we're going to go through it just to get on the same page with these definitions. This is the hard part of roasting that, as roasters, you don't need to know all of this to turn coffee brown. But let's go through it. So chemical processes are the heat of coffee roasting, degrades some, forms new, and alters existing compounds that exist within the coffee. We have the Maillard reaction. Who's heard of the Maillard reaction? Yeah! This also is what makes steak taste yummy or grilled pineapple. It is a non-enzymatic browning reaction. Basically that means enzymatic browning reaction is when enzymes... hit oxygen and they turn them brown. So if you have an apple that you slice or a fruit and you set it out it changes the color of the fruit but this one is applying heat it changes the color. So the carbohydrates and amino acids react to one another carbon dioxide is created and released. Then we have the Strucker degradation. Who's heard of Strucker degradation? You guys have read a couple books out here. Strucker degradation is amino acids reacting with carbonyl-grilled molecules that create compounds that impact aroma and flavor, and flavor-producing compounds within the coffee. Great. Next one, sugar caramelization. Who's heard of caramelization? That's tasty. We love it. Sugar caramelization is where complex carbohydrates, long-chain carbohydrates, break down into littler carbohydrates, smaller sugar molecules that make things taste good. And then we have the creation of volatile and non-volatile compounds. Volatile compounds have a high vapor pressure at room temperature. They contribute to aroma. Basically, they're things that go into... the air easily that's why they create aroma because they're in the air we smell them we sense them through the olfactory the retro nasal senses and then we have non-volatile compounds which have a low vapor pressure they're stable they stay in the coffee and they're responsible for more of like the flavor that we get on our tongue i'm not going to go into the neural you should catch uh fabiana carvalho's talk if you want to hear about the neuro neurobiology Um, alright, oh, not yet. Uh, just to finish on these, uh, the chemical changes. So, these all seem pretty complicated, but, like, I am not a scientist, I'm not a chemist, I'm not a physicist. But, and as a coffee roaster, we don't really need to know the mechanics that all of this entails in order to roast coffee well, in order to roast coffee consistency, and to become better coffee roasters in general. In order to, in order to do the coffee roasting thing, we're going to skip that one, in order to do the coffee roasting thing, we really need to Focus on three things. First, the coffee itself, the green coffee, the input that you start with. Then we have the machine, the thing that turns the coffee brown, and we have flavor and results. So we're going to start with green coffee. Coffee has many attributes. There's variety, density, size, growing conditions, altitude, rainfall, soil, country of origin, region of origin, moisture level, water activity, post-harvest, many many attributes to green coffee. And there's also post-harvest processing, which is natural or washed or honey processed coffee. And there's also whether a coffee has anaerobic fermentation, carbonic maceration, fermentation, co-fermentation, etc. And all of these things lead to what I'm calling intrinsic potential with coffee. quality and character of a coffee. So all of these things listed above, is the coffee that you're roasting most likely going to taste more like chocolate and caramel? Or is it going to have more florals, citric notes, lighter acidity? So this is a big list. And in order to simplify, I kind of propose that we limit this list to just a few attributes. Boink! See, we're simplifying, making it easy. Of course, if you want to get super into detail, you can sure figure out all of these attributes for every single coffee that you roast. I'm trying to make it a little more simple. We're breaking it down. So I propose that we focus on variety, density, size, post-harvest processing, and intrinsic potential. So, yeah, this is kind of where my brain goes when I'm trying to approach a new coffee. Break these into categories. So I lump variety and post-harvest processing together, not because they're the same thing, but because the way that you can approach a coffee can change based on these characteristics. So for variety and post-harvest processing, I think about approaching the coffee with my preconceived ideas about this coffee itself. When we hear Gesha, what do we think? Floral. Yeah. So the variety and post-harvest character. And when we hear natural versus washed, what do we think? Fruity. Yeah. So for me, this is about coming to the coffee with what we know or what we have experienced. in the past and understanding these kind of preconceived ideas takes time, exposure, practice, and paying attention to coffee that you're seeing. Through gathering this experience we know naturals generally taste more fruity, washed coffees taste more balanced, and the differences in variety. Then we have density and size coming down. And this is actually looking at the coffee that you're roasting, the sample or the green coffee that you have in your hands that you're going to put in the machine. And we can assess the physical... characteristics. Again, I listed all of those characteristics before, but for me and my experience, focusing on density and density and size is really kind of gets down to the nitty gritty of how to first approach a coffee. So this affects how the coffee absorbs the heat while it's being roasted. Denser beans generally absorb more heat, more energy throughout the roasting process, so they can handle a little bit more aggressive heat application. And bigger beans require more energy in order to fully develop to the center of the bean. If you think of something this big, you need more energy to get to the middle, whereas if you start with something this big, not as much. Of course, all of this will depend on your roasting machine. If you have a machine that does air roaster versus traditional drum roaster, heat application will be a little bit different. But we'll get to that in a minute. But in general, if you understand how the density and size react to heat application, we can really focus in on this bit. Of course, these attributes are also affected by other factors. I found that the more post-harvest processing a coffee seed undergoes, the less dense the coffee bean is. So super high fermentation anaerobic coffees are generally... Less dense than a washed coffee. Again, this can change from coffee to coffee, but it's something to consider. And also certain varieties produce smaller beans than others. Ethiopian heirloom varieties are generally teeny tiny. And then you have Mara Gohibe, which is Big Voice. So then, to summarize this bit, we're coming in with what we think we know about the coffee. Then we're looking at the coffee itself, And then we're talking about the intrinsic potential. And this requires a little bit of roasting, a little bit of development. So this will give you an idea of what this particular coffee is capable of. And once you know all of this information about a coffee, with the type characteristic, the physical characteristics, what it tastes like, I think we can then start to approach the coffee with a little more confidence, a little bit more understanding of what might occur. So, next. Exercise number one to understand, help you understand green coffee. So, I think it's really important to Develop our skills as coffee roasters, which means roasting coffee. And this is one way that I suggest to approach doing this. I am not someone who can take a sample roast and apply it. directly at due production i know there's some people out there who say they can do it good for you uh i am not that person but i still think that there are really um important and useful applications for a sample roasting of one coffee in various ways so my suggestion this exercise take a coffee you want to assess and sample roast it in three different ways Number one, sample roast it or roast it as you would usually do. Number two, cut the roast short by 10 to 20 seconds so you're roasting a little bit less. And then number three, develop the roast 10 to 20 seconds longer than you would usually do. You can also do this instead of changing the time. You can change the temperature up a little bit and down a little bit. And then... taste those coffees blind, not knowing which one was underdeveloped, which one was overdeveloped, so that you can really assess what this coffee does at different levels of development. Compare your notes and see what you taste, what you like, how they're different, and or how they're similar. There are some coffees that are really, really different with minor differences in the roasting, and other coffees that are like, you can do anything to them and they'll still taste the same. So this is a good way to learn that coffee. All right. Now, we're going on to machine. So green coffee. Next is machine. Managing your machine. machine requires time and practice. And you can watch all the YouTube videos, take all courses, read all the books, and still you need to spend time on your roasting machine. Because every roasting machine, again, is different. You need to know how your roasting machine works and how different coffees respond within the machine you are using. So most roasters will start with a roasting philosophy, an idea of how to approach coffee. This doesn't have to be a comprehensive theory of coffee roasting. It means... what do you want to achieve within the roasting process? Do you want to go light and showcase the coffee's, we call it, the intrinsic characteristics? Do you want to develop the sugars more, end up with something a little bit more sweet? Or do you want to go dark and bring out some bitter characteristics of the coffee? This can depend on personal preferences and your customer base. But in order to carry this out, you want to know whether or not you can achieve these results with your machine. Again, it all depends on your machine. So understanding your machine specifications is top importance, top priority. There are many types of roasting machines that apply heat in different ways, and I'm not going to go into all of those because those you can find on YouTube, those you can find in blogs, so we're going to kind of skip through that. But I think in order to make coffee roasting more approachable, if you have a roasting machine available to you, what you need to know is your machine. What happens when you turn your heat all the way up? What happens when you adjust the airflow midway through the roast versus towards the end? What happens when you roast a small batch versus a small batch versus when you max your machine out and load it all the way up? How quickly does your machine... react when you push the buttons. I've worked on machines that are super, super responsive. You push a button, the roasting curve changes. I've also roasted on machines that take 30 seconds for an adjustment to be reflected in the roasting process. So it's really important to know. the parameters of your machine. So we come to exercise number two. We call it the hot and heavy exercise for fun. So in this exercise we're learning the parameters, the maxes, and what our machines can do. So I suggest take a coffee. take a coffee, any coffee, and load your machine to full capacity. If you have a 15 kilogram, I mean that's a lot of coffee, so have some place to maybe do it before the holidays, and then you can give this out as gifts to all your friends and family who don't care so much much about coffee. But anyway, take the max capacity and fill your machine and roast it all the way to a typical end temp that you would usually do for a roasting style. It will likely take longer than you're used to, but that's okay. We want to know how long it takes when you put 100% batch capacity in. And then part two, load your machine at 50% capacity and do the same 100% heat application. just to see what happens for your machine when you get it, when you basically send it, when you use 100% heat. Then notice how long that roast takes. You kind of, you can roast, you know, if you wanted to do a part three, you can do it at 20%. You can do it at 10% if you wanted. But knowing the parameters of your machine is important. And then also, finally, please always taste your results. Always, always, always. Yes. even if you mess up a roast, taste your results, because that's where we're getting to that next, foreshadowing, that's where the real learning happens. But yeah, this is an exercise that I recommend to get to know your machine. Yes, it's also worth mentioning there are different purposes for roasting coffee. Not all roasting is the same. We have sample roasting, the goal of which is usually to roast light in order to reveal what might be within the beans. Some, like many... roasters will do this when they're deciding what coffees to bring in, which coffees to buy for their roastery. I know other roasters, once the coffee arrives to their roastery, they'll do this as well just to kind of refresh their mind and see what's possible. Then we have profile roasting, the goal of which is to find a roast profile that suits the coffee or the roaster's needs, which includes your customers. I don't go super in detail on this. I'm focusing on roasting, but... The purpose of roasting is to serve the coffee in the end. We also have to consider what our customers are asking for, what our customers want. But yeah, profile roasting, the purpose is to find a roast profile that works for the coffee. And then we have production roasting. The goal of production roasting is to repeat the profile over and over and over so that we get the same results, the same consistency every time. So I think it's, this is kind of an aside, but it's important to point out, it's important to know and remember that there are different purposes to different parts of roasting. So after we figure out and can kind of demystify green coffee, after we know our machine a little bit more, next is understanding the flavor, understanding the results. Because you can roast the best coffee in the world, and if you can't taste it or somebody can't taste it, know that it worked. It doesn't really, you can't really sell it. So we want to understand the results of how the coffee has interacted with the roasting machine. In my opinion, again, this is the most important aspect of growing as a roaster. If you really want to become a better roaster, become a better taster. Because if you can't taste the results again, what's the point? We all like coffee because it's tasty, right? So, there are a few ways to develop your palate as sensory professionals and coffee roasters. The first is to taste a lot of things, a lot of other things, a lot of non-coffee things, fruits, vegetables, chocolates, nuts, and see what they taste like. Because that's how we know when a flavor note is on a bag of coffee, how do you know what it's referring to. These are mini exercises. Get a lot of similar foods. Maybe a bunch of citrus fruits, maybe a bunch of chocolates, maybe a bunch of nuts. Taste them all together and think about or notice the differences and the similarities between them all. And then also developing your palate in coffee is also important. We can get more specific to coffee. So one way to do this, taste many coffees, especially coffees from other roasters. If you're a roaster, you should be drinking coffee from other roasters as well. What do you like about them? What do you not like? Like, pay attention to the things we talked about before, the processing methods, the varieties that you like, so that you can kind of hone in on what you as a roaster want to focus on. Try to describe what you had and what you liked and what you disliked about the coffee. Also, shameless plug, my friend Carly has a company called Cherry Love, and she sends out four different coffees every two months. That's a really, really, really great way to taste a bunch of coffee, so check out Cherry Love on Israel. And then, I suggest that we taste everything that you roast. As I said before, but I'm going to say it again. Taste everything that you roast. Because if you overdeveloped a coffee, or underdeveloped a coffee, you're not going to know if that is a bad thing, or maybe that's a good thing. Maybe you like it. There have been a couple of times where I've been roasting. I don't know if this has happened to you, but the power cuts off in the middle of a roast. What are you to do? You have coffee that's been sitting there for four minutes. It's been getting hot four minutes. Do you just throw that away? I suggest not. I suggest re-roasting and then taste it. Does it taste terrible? Or maybe it might taste fine and good and maybe even better than what you would think. In fact, Rob Hoos, if you follow Rob... Rob Hoos on socials or on his blog, he is actually suggesting to do this as a specific roasting approach to increase the solubility of coffee. So re-roasting, double roasting, it's a good time. But yeah, taste everything that you do. And we're going to talk about a palate training exercise. Exercise number three. People who compete in cup tasters competitions, that was I think going on this weekend, have to do this and it's a great way to keep your palate sharp, to develop your ability to differentiate between flavors and different coffees. Triangulation, it means three. Get three cups, brew two different coffees, fill two of those cups with the same coffee, and one of those cups with a different coffee. It's best if you can do this with coffees of the same temperature. But yeah. And then shuffle them around even better if you have a friend or a family member who can shuffle them for you. So you don't know which one is which. Mark the bottom of a, this should be in up there. But make sure that you mark the bottom the one that's different, mark the bottom of the cup so that you know when you're checking if you did it correctly. And then taste them. See if you can tell a difference. If you can tell which one is kind of the odd cup out, great, you did it. If you can't, do it again but with more similar coffees. This is a really great way. I mean, you can start out with two natural, like one coffee that's a natural and one coffee that's a washed. Taste those, see if you can see if they're different. If you can, then maybe take a glass of water coffee that's a natural and a honey or even a washed and a honey and do it as well. Take coffees that are the same process but different varieties and do it as well. I know or I have heard that folks who are really, really getting into top tier of cup tasters will take coffees from the same farm grown on different plots of land and you can tell the difference. Some people can tell, I can't tell the difference, but it's a way to develop your palate and I suggest you do it. Alright, so yeah, those are my exercises. We started with green coffee. We go to knowing your machine and then developing your palate. Super important things in order to become a better roaster. Hopefully make things a little bit more simple. We're going to squeeze. Well, I'll mention this. I also wanted to talk today about occupational hazards that roasters face in the roastery. I don't have time to go over the whole thing, but I'm going to go over it quickly because this is something that I think as roasters we don't really talk about as much. much. Everything I've covered ahead of this, I feel like there's videos, there's blogs, there are things you can look up. And there's also, you know, it really just requires your experience, you doing things, you repeating things, roasting, tasting, and understanding green. But these things, occupational hazards, are things we don't talk about in roasting. And I think that's a shame, because fires can be very bad. Acute dangers, that's... like cuts, bruises. I know folks who have gotten concussions, folks who have gotten, you know, run into by the forklift, things that happen in roasteries that can cause physical damage. So I'm all this to say I'm writing a series. These articles in Roast magazine that cover... All of this. It's a five-part series. So if you check out Roast Magazine, you can read my articles about these things. But, again, all this to say, I think every roaster should have plans and practices for fire management. And all roasters should talk about the acute dangers that we face and how to mitigate and prevent them, whether that be cuts, bruises, concussions, and other kind of accidents that happen. happen in the workplace. We also have chronic conditions and allergies. Does anybody have green coffee allergy here? Anybody? Green coffee allergy is a real thing, and it can develop over time. I know more than a handful of coffee roasters who, after five, ten years in coffee, have developed green coffee allergies. And we don't talk about that. We don't talk it. So for this I recommend, I mean tip number one, wear a mask when you're scooping green coffee and limit your exposure outside of kind of the necessary requirements for for green coffee exposure. We also have chronic conditions. Anybody have tennis elbow? I have tennis elbow from scooping coffee for so many years. So the chronic conditions can include tennis elbow, back strain, muscle aches. Basically, the impacts of a long-term career in coffee roasting can add up. And then we have mental health and burnout. Roasting, most of us roasters like to kind of be on our own at the roaster, doing our own thing. But especially with production, it can really kind of add up over time. get kind of boring. So I suggest that we attend events like this, talk to other roasters, and do other professional development exercises in order to kind of stay engaged and not hit a, you know, a place where we hate what we do because roasting is fun, right? Yeah. Okay, we're gonna skip through these ones. Great. And we're coming to the end. So, again, roasting is not that hard. It's applying heat to raw coffee beans to create a series of chemical and physical changes. Again, my simplification, turning coffee brown. by making it hot. But being a coffee roaster is a lot more than just doing that. It's the daily, it's palate development, it's understanding our roasting machine, and it's getting familiar and competent with green coffee. So, roasting isn't that hard. Try things, taste things, question everything, try it yourself, and that's the end. Thank you. Questions, I think. I prefer Q&As. It's more fun. Yeah, kilos. I've roasted, the question is how many kilos am I used to roasting? I've roasted primarily on 12 kilo Diedrich, 15 kilo Loring, 35 kilo Loring, and 70 kilo Loring. Those are my, like... the machines I have most experience on. So, yeah, I usually roast in pounds, so I have to do a little conversion. But those are the machines that I'm most familiar with. Usually not maxing those out. I mean, I think even on a 70-kilogram machine, we would often do probably 60... 65 kilos max most of the time. Yeah. Does that answer your question? Yeah. Good? Yeah. Ever compete in the wrestling competition? I did and I did really bad. I did really poorly. Yeah, I've competed in the roasting competition twice. The first time I did, actually no, three times. Just at the regional level. in the U.S., we have kind of a couple different levels. I competed three times. One, my first time is in 2017, and I actually did decent, but I think it was beginner's luck. I didn't know a ton of what I was doing. The competition was also a little bit different then, and also, I will say, I learned a ton by competing that year. I, like, really invested to the Time and energy. I reached out to my community who was there and like I was also a new roaster. I started roasting in 2017. So doing the roasting competition was a little bit of like going out on a limb for me. But yeah, it was like it was an amazing way to. deep dive to connect with other roasters in the town I was living in. And I learned a ton by competing. I did the roasting competition last year and I think the year before. And I did not do very well. It's okay though. It's okay. I chalk it up to I did not prepare and I didn't understand the competition very well. If you attended August Talk, the number Number two tip, number three tip, read the rules. I didn't do a good job of reading the rules, knowing how to get points, knowing where to lose points. I didn't understand the scoring system. But I did judge the roasting competition in the U.S. this year at the regional level again, and I understand it a lot better now. So if you're thinking about competing, I would super suggest judging first, especially with roasting, because the roasting competition, I have a lot of thoughts. That's more than we have time for today. But the roasting competition I think is difficult to succeed consistently. All the competitions are difficult of course, but yeah. Great question. Are you competing? Nice. You did? In two weeks? In what country? Germany? Good luck. So my tip would be, like my number one advice coming from the especially judging side is look at the score sheet. Understand the score sheet, understand where you will get points, and understand where you can lose points. Because competition is, it's a competition. You win by getting points. Other questions? I'm RoasterKat on Instagram and YouTube. So if you don't follow me, follow me. If you have questions, please reach out. I love to talk roasting. And yeah, thank you so much for being here.

Hola, hola, hola, hola, hola. Está funcionando? Is it working?

Debo presentar en español mejor? Lo siento, que no. El próximo año voy a hacer en español, pero this year I'll do it in English.

Um, yeah. I am... here today to talk about coffee roasting the name of my talk is roasting isn't that hard how many roasters are here raise your hand let me see yeah yeah yeah yeah yeah uh yeah uh so roasting isn't that hard, it's also not that easy.

So I want to talk about the difficult and not so difficult parts of roasting. Really I want to demystify, break down, simplify the parts of roasting that I think a lot of us roasters, maybe even baristas or consumers, have a hard time understanding so that we can all feel a little bit more comfortable or a little bit more confident approaching roasting. So yeah. Roasting isn't that hard.

People have been roasting coffee for centuries, literally, without the use of modern technology, without roasting software, though thanks Cropster for sponsoring this event, and without... the use of cupping forms. People have been turning coffee brown.

So with the skills and with the tools available to us today, if you understand a few core concepts and master a few key skills, you can roast coffee with confidence, with ease, and with consistency. As I said, and as we all know, roasting also isn't that easy. The world of roasting is full of complicated concepts and contrasting opinions about what makes a good coffee roast, what makes a bad coffee roast. And there's a lot of technical jargon to sort through.

So it takes time to learn these concepts, to understand these ideas, to get comfortable with green coffee, with machines, and with tasting coffee, with understanding the effect that roasting has on green coffee. So, not to mention, as we all know, both as baristas, consumers, roasters, every coffee is different. Every machine is different. What works for one might not work for another.

This is our job, this is our work to develop these skills. So, as coffee roasters, how are we to maintain quality, consistency in our day-to-day jobs? I'm Kat Malheim.

Hello. Some of you may know me as RoasterKat on Instagram and YouTube. And I've been posting on educational things on Instagram pretty much for the seven years since I started learning how to roast.

mostly because I was entering the world of roasting and I didn't see other educational tools out there. There was maybe one or two books, a couple of blogs, but outside of attending expensive events or... master classes, it was really hard to find information.

So as I started learning, I pretty much started posting on Instagram the things I was learning, mostly to remember myself, but also to share with people who didn't have access to those same rooms that I was able to be in and those classes I was able to take. So today I'm going to talk about the easy and hard parts of being a coffee roaster and we're going to break down some key concepts, highlight what I have found to be critical parts of roasting coffee, and then we're going to demystify the roasting process of it. This will also include some actionable tips, tricks, and exercises, so get your phones out and be ready to take pictures and then go back to your own roasteries and try out some of these things.

So let's go. Are you ready? All right, there are different definitions of coffee roasting, but really essentially, coffee roasting is applying heat to raw coffee beans to create a series of physical and chemical changes within the coffee beans.

Another way to put it is, Turning coffee brown by making it hot. See? It's simple.

But the difficult part is doing this in a controlled way and doing it in a way that we can replicate so that we have consistency. I know, you know, this sounds easy, but we've all, I mean, maybe it's just me, but as roasters, haven't we all gone a little too short? We end up with grassy and harsh notes that really take out the acidity, or we go a little too far with the coffee, and we end up with burnt and roasty notes, and they overpower the sweetness.

So our work is finding that middle bit and then doing it over. So to get on the same page, we're going to go over some of these physical and chemical changes that happen during coffee roasting. So the physical changes, basic definition, are the visible characteristics of coffee seed change, the things we can see, the things we can notice.

Obviously, coffee changes color. We all have seen that. That's part of my definition.

and turning coffee brown. So coffee goes from a greenish, well, we call it green coffee, greenish, bluish, tannish color to a range of browns. Also, coffee's... Seed size increases 20 to 50 percent depending on the heat application depending on the variety of coffee that you're roasting We have mass decrease. So the coffee even though it gets bigger It loses weight in the roasting process part of that is moisture water Water is released from the beans during roasting because you're putting heat on it.

It evaporates and We go from about 10 to 12 percent, which is usually ideal for specialty coffee, to about 2.5 percent in roasted coffee. The coffee also increases in brittleness and porosity. This allows us to grind and brew the coffee, which is kind of the point of the whole thing. The cells swell due to this heat application. They become harder, and then when we put it through a grinder, they break up.

If you go dark enough, oils migrate to the surface. Another thing we can see. Most of the time in specialty, we don't go that far, but sometimes you do.

And if that's what you intended to do, great. Then we have the chemical changes. This one is a lot of words.

So we're going to go through it just to get on the same page with these definitions. This is the hard part of roasting that, as roasters, you don't need to know all of this to turn coffee brown. But let's go through it. So chemical processes are the heat of coffee roasting, degrades some, forms new, and alters existing compounds that exist within the coffee.

We have the Maillard reaction. Who's heard of the Maillard reaction? Yeah!

This also is what makes steak taste yummy or grilled pineapple. It is a non-enzymatic browning reaction. Basically that means enzymatic browning reaction is when enzymes... hit oxygen and they turn them brown.

So if you have an apple that you slice or a fruit and you set it out it changes the color of the fruit but this one is applying heat it changes the color. So the carbohydrates and amino acids react to one another carbon dioxide is created and released. Then we have the Strucker degradation.

Who's heard of Strucker degradation? You guys have read a couple books out here. Strucker degradation is amino acids reacting with carbonyl-grilled molecules that create compounds that impact aroma and flavor, and flavor-producing compounds within the coffee.

Great. Next one, sugar caramelization. Who's heard of caramelization?

That's tasty. We love it. Sugar caramelization is where complex carbohydrates, long-chain carbohydrates, break down into littler carbohydrates, smaller sugar molecules that make things taste good. And then we have the creation of volatile and non-volatile compounds.

Volatile compounds have a high vapor pressure at room temperature. They contribute to aroma. Basically, they're things that go into...

the air easily that's why they create aroma because they're in the air we smell them we sense them through the olfactory the retro nasal senses and then we have non-volatile compounds which have a low vapor pressure they're stable they stay in the coffee and they're responsible for more of like the flavor that we get on our tongue i'm not going to go into the neural you should catch uh fabiana carvalho's talk if you want to hear about the neuro neurobiology Um, alright, oh, not yet. Uh, just to finish on these, uh, the chemical changes. So, these all seem pretty complicated, but, like, I am not a scientist, I'm not a chemist, I'm not a physicist.

But, and as a coffee roaster, we don't really need to know the mechanics that all of this entails in order to roast coffee well, in order to roast coffee consistency, and to become better coffee roasters in general. In order to, in order to do the coffee roasting thing, we're going to skip that one, in order to do the coffee roasting thing, we really need to Focus on three things. First, the coffee itself, the green coffee, the input that you start with. Then we have the machine, the thing that turns the coffee brown, and we have flavor and results. So we're going to start with green coffee.

Coffee has many attributes. There's variety, density, size, growing conditions, altitude, rainfall, soil, country of origin, region of origin, moisture level, water activity, post-harvest, many many attributes to green coffee. And there's also post-harvest processing, which is natural or washed or honey processed coffee.

And there's also whether a coffee has anaerobic fermentation, carbonic maceration, fermentation, co-fermentation, etc. And all of these things lead to what I'm calling intrinsic potential with coffee. quality and character of a coffee.

So all of these things listed above, is the coffee that you're roasting most likely going to taste more like chocolate and caramel? Or is it going to have more florals, citric notes, lighter acidity? So this is a big list. And in order to simplify, I kind of propose that we limit this list to just a few attributes.

Boink! See, we're simplifying, making it easy. Of course, if you want to get super into detail, you can sure figure out all of these attributes for every single coffee that you roast.

I'm trying to make it a little more simple. We're breaking it down. So I propose that we focus on variety, density, size, post-harvest processing, and intrinsic potential.

So, yeah, this is kind of where my brain goes when I'm trying to approach a new coffee. Break these into categories. So I lump variety and post-harvest processing together, not because they're the same thing, but because the way that you can approach a coffee can change based on these characteristics. So for variety and post-harvest processing, I think about approaching the coffee with my preconceived ideas about this coffee itself. When we hear Gesha, what do we think?

Floral. Yeah. So the variety and post-harvest character. And when we hear natural versus washed, what do we think? Fruity.

Yeah. So for me, this is about coming to the coffee with what we know or what we have experienced. in the past and understanding these kind of preconceived ideas takes time, exposure, practice, and paying attention to coffee that you're seeing. Through gathering this experience we know naturals generally taste more fruity, washed coffees taste more balanced, and the differences in variety. Then we have density and size coming down.

And this is actually looking at the coffee that you're roasting, the sample or the green coffee that you have in your hands that you're going to put in the machine. And we can assess the physical... characteristics.

Again, I listed all of those characteristics before, but for me and my experience, focusing on density and density and size is really kind of gets down to the nitty gritty of how to first approach a coffee. So this affects how the coffee absorbs the heat while it's being roasted. Denser beans generally absorb more heat, more energy throughout the roasting process, so they can handle a little bit more aggressive heat application. And bigger beans require more energy in order to fully develop to the center of the bean.

If you think of something this big, you need more energy to get to the middle, whereas if you start with something this big, not as much. Of course, all of this will depend on your roasting machine. If you have a machine that does air roaster versus traditional drum roaster, heat application will be a little bit different. But we'll get to that in a minute. But in general, if you understand how the density and size react to heat application, we can really focus in on this bit.

Of course, these attributes are also affected by other factors. I found that the more post-harvest processing a coffee seed undergoes, the less dense the coffee bean is. So super high fermentation anaerobic coffees are generally...

Less dense than a washed coffee. Again, this can change from coffee to coffee, but it's something to consider. And also certain varieties produce smaller beans than others. Ethiopian heirloom varieties are generally teeny tiny.

And then you have Mara Gohibe, which is Big Voice. So then, to summarize this bit, we're coming in with what we think we know about the coffee. Then we're looking at the coffee itself, And then we're talking about the intrinsic potential. And this requires a little bit of roasting, a little bit of development. So this will give you an idea of what this particular coffee is capable of.

And once you know all of this information about a coffee, with the type characteristic, the physical characteristics, what it tastes like, I think we can then start to approach the coffee with a little more confidence, a little bit more understanding of what might occur. So, next. Exercise number one to understand, help you understand green coffee. So, I think it's really important to Develop our skills as coffee roasters, which means roasting coffee.

And this is one way that I suggest to approach doing this. I am not someone who can take a sample roast and apply it. directly at due production i know there's some people out there who say they can do it good for you uh i am not that person but i still think that there are really um important and useful applications for a sample roasting of one coffee in various ways so my suggestion this exercise take a coffee you want to assess and sample roast it in three different ways Number one, sample roast it or roast it as you would usually do. Number two, cut the roast short by 10 to 20 seconds so you're roasting a little bit less. And then number three, develop the roast 10 to 20 seconds longer than you would usually do.

You can also do this instead of changing the time. You can change the temperature up a little bit and down a little bit. And then...

taste those coffees blind, not knowing which one was underdeveloped, which one was overdeveloped, so that you can really assess what this coffee does at different levels of development. Compare your notes and see what you taste, what you like, how they're different, and or how they're similar. There are some coffees that are really, really different with minor differences in the roasting, and other coffees that are like, you can do anything to them and they'll still taste the same. So this is a good way to learn that coffee. All right.

Now, we're going on to machine. So green coffee. Next is machine. Managing your machine.

machine requires time and practice. And you can watch all the YouTube videos, take all courses, read all the books, and still you need to spend time on your roasting machine. Because every roasting machine, again, is different.

You need to know how your roasting machine works and how different coffees respond within the machine you are using. So most roasters will start with a roasting philosophy, an idea of how to approach coffee. This doesn't have to be a comprehensive theory of coffee roasting. It means...

what do you want to achieve within the roasting process? Do you want to go light and showcase the coffee's, we call it, the intrinsic characteristics? Do you want to develop the sugars more, end up with something a little bit more sweet? Or do you want to go dark and bring out some bitter characteristics of the coffee?

This can depend on personal preferences and your customer base. But in order to carry this out, you want to know whether or not you can achieve these results with your machine. Again, it all depends on your machine.

So understanding your machine specifications is top importance, top priority. There are many types of roasting machines that apply heat in different ways, and I'm not going to go into all of those because those you can find on YouTube, those you can find in blogs, so we're going to kind of skip through that. But I think in order to make coffee roasting more approachable, if you have a roasting machine available to you, what you need to know is your machine. What happens when you turn your heat all the way up? What happens when you adjust the airflow midway through the roast versus towards the end?

What happens when you roast a small batch versus a small batch versus when you max your machine out and load it all the way up? How quickly does your machine... react when you push the buttons.

I've worked on machines that are super, super responsive. You push a button, the roasting curve changes. I've also roasted on machines that take 30 seconds for an adjustment to be reflected in the roasting process. So it's really important to know.

the parameters of your machine. So we come to exercise number two. We call it the hot and heavy exercise for fun.

So in this exercise we're learning the parameters, the maxes, and what our machines can do. So I suggest take a coffee. take a coffee, any coffee, and load your machine to full capacity.

If you have a 15 kilogram, I mean that's a lot of coffee, so have some place to maybe do it before the holidays, and then you can give this out as gifts to all your friends and family who don't care so much much about coffee. But anyway, take the max capacity and fill your machine and roast it all the way to a typical end temp that you would usually do for a roasting style. It will likely take longer than you're used to, but that's okay. We want to know how long it takes when you put 100% batch capacity in. And then part two, load your machine at 50% capacity and do the same 100% heat application.

just to see what happens for your machine when you get it, when you basically send it, when you use 100% heat. Then notice how long that roast takes. You kind of, you can roast, you know, if you wanted to do a part three, you can do it at 20%. You can do it at 10% if you wanted. But knowing the parameters of your machine is important.

And then also, finally, please always taste your results. Always, always, always. Yes.

even if you mess up a roast, taste your results, because that's where we're getting to that next, foreshadowing, that's where the real learning happens. But yeah, this is an exercise that I recommend to get to know your machine. Yes, it's also worth mentioning there are different purposes for roasting coffee. Not all roasting is the same.

We have sample roasting, the goal of which is usually to roast light in order to reveal what might be within the beans. Some, like many... roasters will do this when they're deciding what coffees to bring in, which coffees to buy for their roastery. I know other roasters, once the coffee arrives to their roastery, they'll do this as well just to kind of refresh their mind and see what's possible.

Then we have profile roasting, the goal of which is to find a roast profile that suits the coffee or the roaster's needs, which includes your customers. I don't go super in detail on this. I'm focusing on roasting, but...

The purpose of roasting is to serve the coffee in the end. We also have to consider what our customers are asking for, what our customers want. But yeah, profile roasting, the purpose is to find a roast profile that works for the coffee. And then we have production roasting.

The goal of production roasting is to repeat the profile over and over and over so that we get the same results, the same consistency every time. So I think it's, this is kind of an aside, but it's important to point out, it's important to know and remember that there are different purposes to different parts of roasting. So after we figure out and can kind of demystify green coffee, after we know our machine a little bit more, next is understanding the flavor, understanding the results. Because you can roast the best coffee in the world, and if you can't taste it or somebody can't taste it, know that it worked.

It doesn't really, you can't really sell it. So we want to understand the results of how the coffee has interacted with the roasting machine. In my opinion, again, this is the most important aspect of growing as a roaster. If you really want to become a better roaster, become a better taster. Because if you can't taste the results again, what's the point?

We all like coffee because it's tasty, right? So, there are a few ways to develop your palate as sensory professionals and coffee roasters. The first is to taste a lot of things, a lot of other things, a lot of non-coffee things, fruits, vegetables, chocolates, nuts, and see what they taste like. Because that's how we know when a flavor note is on a bag of coffee, how do you know what it's referring to. These are mini exercises.

Get a lot of similar foods. Maybe a bunch of citrus fruits, maybe a bunch of chocolates, maybe a bunch of nuts. Taste them all together and think about or notice the differences and the similarities between them all. And then also developing your palate in coffee is also important.

We can get more specific to coffee. So one way to do this, taste many coffees, especially coffees from other roasters. If you're a roaster, you should be drinking coffee from other roasters as well.

What do you like about them? What do you not like? Like, pay attention to the things we talked about before, the processing methods, the varieties that you like, so that you can kind of hone in on what you as a roaster want to focus on. Try to describe what you had and what you liked and what you disliked about the coffee.

Also, shameless plug, my friend Carly has a company called Cherry Love, and she sends out four different coffees every two months. That's a really, really, really great way to taste a bunch of coffee, so check out Cherry Love on Israel. And then, I suggest that we taste everything that you roast. As I said before, but I'm going to say it again.

Taste everything that you roast. Because if you overdeveloped a coffee, or underdeveloped a coffee, you're not going to know if that is a bad thing, or maybe that's a good thing. Maybe you like it.

There have been a couple of times where I've been roasting. I don't know if this has happened to you, but the power cuts off in the middle of a roast. What are you to do?

You have coffee that's been sitting there for four minutes. It's been getting hot four minutes. Do you just throw that away? I suggest not.

I suggest re-roasting and then taste it. Does it taste terrible? Or maybe it might taste fine and good and maybe even better than what you would think. In fact, Rob Hoos, if you follow Rob... Rob Hoos on socials or on his blog, he is actually suggesting to do this as a specific roasting approach to increase the solubility of coffee.

So re-roasting, double roasting, it's a good time. But yeah, taste everything that you do. And we're going to talk about a palate training exercise.

Exercise number three. People who compete in cup tasters competitions, that was I think going on this weekend, have to do this and it's a great way to keep your palate sharp, to develop your ability to differentiate between flavors and different coffees. Triangulation, it means three.

Get three cups, brew two different coffees, fill two of those cups with the same coffee, and one of those cups with a different coffee. It's best if you can do this with coffees of the same temperature. But yeah.

And then shuffle them around even better if you have a friend or a family member who can shuffle them for you. So you don't know which one is which. Mark the bottom of a, this should be in up there.

But make sure that you mark the bottom the one that's different, mark the bottom of the cup so that you know when you're checking if you did it correctly. And then taste them. See if you can tell a difference.

If you can tell which one is kind of the odd cup out, great, you did it. If you can't, do it again but with more similar coffees. This is a really great way. I mean, you can start out with two natural, like one coffee that's a natural and one coffee that's a washed. Taste those, see if you can see if they're different.

If you can, then maybe take a glass of water coffee that's a natural and a honey or even a washed and a honey and do it as well. Take coffees that are the same process but different varieties and do it as well. I know or I have heard that folks who are really, really getting into top tier of cup tasters will take coffees from the same farm grown on different plots of land and you can tell the difference.

Some people can tell, I can't tell the difference, but it's a way to develop your palate and I suggest you do it. Alright, so yeah, those are my exercises. We started with green coffee.

We go to knowing your machine and then developing your palate. Super important things in order to become a better roaster. Hopefully make things a little bit more simple.

We're going to squeeze. Well, I'll mention this. I also wanted to talk today about occupational hazards that roasters face in the roastery.

I don't have time to go over the whole thing, but I'm going to go over it quickly because this is something that I think as roasters we don't really talk about as much. much. Everything I've covered ahead of this, I feel like there's videos, there's blogs, there are things you can look up.

And there's also, you know, it really just requires your experience, you doing things, you repeating things, roasting, tasting, and understanding green. But these things, occupational hazards, are things we don't talk about in roasting. And I think that's a shame, because fires can be very bad. Acute dangers, that's... like cuts, bruises.

I know folks who have gotten concussions, folks who have gotten, you know, run into by the forklift, things that happen in roasteries that can cause physical damage. So I'm all this to say I'm writing a series. These articles in Roast magazine that cover...

All of this. It's a five-part series. So if you check out Roast Magazine, you can read my articles about these things.

But, again, all this to say, I think every roaster should have plans and practices for fire management. And all roasters should talk about the acute dangers that we face and how to mitigate and prevent them, whether that be cuts, bruises, concussions, and other kind of accidents that happen. happen in the workplace.

We also have chronic conditions and allergies. Does anybody have green coffee allergy here? Anybody? Green coffee allergy is a real thing, and it can develop over time. I know more than a handful of coffee roasters who, after five, ten years in coffee, have developed green coffee allergies.

And we don't talk about that. We don't talk it. So for this I recommend, I mean tip number one, wear a mask when you're scooping green coffee and limit your exposure outside of kind of the necessary requirements for for green coffee exposure. We also have chronic conditions.

Anybody have tennis elbow? I have tennis elbow from scooping coffee for so many years. So the chronic conditions can include tennis elbow, back strain, muscle aches.

Basically, the impacts of a long-term career in coffee roasting can add up. And then we have mental health and burnout. Roasting, most of us roasters like to kind of be on our own at the roaster, doing our own thing. But especially with production, it can really kind of add up over time. get kind of boring.

So I suggest that we attend events like this, talk to other roasters, and do other professional development exercises in order to kind of stay engaged and not hit a, you know, a place where we hate what we do because roasting is fun, right? Yeah. Okay, we're gonna skip through these ones.

Great. And we're coming to the end. So, again, roasting is not that hard.

It's applying heat to raw coffee beans to create a series of chemical and physical changes. Again, my simplification, turning coffee brown. by making it hot.

But being a coffee roaster is a lot more than just doing that. It's the daily, it's palate development, it's understanding our roasting machine, and it's getting familiar and competent with green coffee. So, roasting isn't that hard. Try things, taste things, question everything, try it yourself, and that's the end.

Thank you. Questions, I think. I prefer Q&As.

It's more fun. Yeah, kilos. I've roasted, the question is how many kilos am I used to roasting? I've roasted primarily on 12 kilo Diedrich, 15 kilo Loring, 35 kilo Loring, and 70 kilo Loring. Those are my, like...

the machines I have most experience on. So, yeah, I usually roast in pounds, so I have to do a little conversion. But those are the machines that I'm most familiar with. Usually not maxing those out.

I mean, I think even on a 70-kilogram machine, we would often do probably 60... 65 kilos max most of the time. Yeah. Does that answer your question? Yeah.

Good? Yeah. Ever compete in the wrestling competition? I did and I did really bad.

I did really poorly. Yeah, I've competed in the roasting competition twice. The first time I did, actually no, three times.

Just at the regional level. in the U.S., we have kind of a couple different levels. I competed three times.

One, my first time is in 2017, and I actually did decent, but I think it was beginner's luck. I didn't know a ton of what I was doing. The competition was also a little bit different then, and also, I will say, I learned a ton by competing that year. I, like, really invested to the Time and energy.

I reached out to my community who was there and like I was also a new roaster. I started roasting in 2017. So doing the roasting competition was a little bit of like going out on a limb for me. But yeah, it was like it was an amazing way to. deep dive to connect with other roasters in the town I was living in.

And I learned a ton by competing. I did the roasting competition last year and I think the year before. And I did not do very well. It's okay though.

It's okay. I chalk it up to I did not prepare and I didn't understand the competition very well. If you attended August Talk, the number Number two tip, number three tip, read the rules. I didn't do a good job of reading the rules, knowing how to get points, knowing where to lose points. I didn't understand the scoring system.

But I did judge the roasting competition in the U.S. this year at the regional level again, and I understand it a lot better now. So if you're thinking about competing, I would super suggest judging first, especially with roasting, because the roasting competition, I have a lot of thoughts. That's more than we have time for today.

But the roasting competition I think is difficult to succeed consistently. All the competitions are difficult of course, but yeah. Great question. Are you competing? Nice.

You did? In two weeks? In what country? Germany? Good luck.

So my tip would be, like my number one advice coming from the especially judging side is look at the score sheet. Understand the score sheet, understand where you will get points, and understand where you can lose points. Because competition is, it's a competition.

You win by getting points. Other questions? I'm RoasterKat on Instagram and YouTube.

So if you don't follow me, follow me. If you have questions, please reach out. I love to talk roasting. And yeah, thank you so much for being here.

Transcript for:Insights from Coffee Roasting Presentation

Transcript for:
Insights from Coffee Roasting Presentation