Roasting 101

Roasting 101

So you want to roast your own coffee. The suggestions and tips offered here will help you prepare for that first roast on any machine that you buy from The Coffee Project.

Initial Steps

First, get your hands on 5 pounds of a Costa Rican, Colombian, or Guatemalan beans. Why? These varieties handle heat well. They are great "learning beans." Although any of our beans can produce world class coffee, you aren't going to worry whether or not your first few roasts win awards right now. At this point, you are only trying to better understand your roasting method and its capabilities, nothing more. Relax and see what can be learned as you go along. Colombian especially is a familiar taste and you'll know right away that you're on the right track. 

With beans in hand, have a pair of oven mitt gloves nearby. Find a place near an open window or below a good kitchen vent that exhausts outside! Not one that recirculates back into the kitchen. 

Identify which electrical outlet you are going to use and dedicate that circuit to the effort at hand while you are roasting. Most home machines are affected by drops in voltage (ie someone starts up the clothes dryer which is drawing power and now your roaster isn't getting the same juice.) You don't want your voltage hopping around on you. 

Pull out a scale, a measuring cup, and a colander. Have a brush or a towel handy to collect any wayward chaff. (What's chaff? its a paper like substance that flakes off the beans while roasting. Some beans have more, some have none. Most home machines collect chaff in a filter.) 

Prepare to take Notes

If you want to be a good home roaster, notes are indispensable. There is nothing like creating the perfect roast and then being unable to replicate it because you can't remember your roasting profiles or when you pulled the beans. So, take a piece of paper and write down some notes (or create a template):

  • Name of Country/Region/Estate/any identifier
  • Date purchased from The Coffee Project
  • Date of the roast
  • Variety (i.e., bourbon, typical, etc.)
  • Wet-processed, dry processed, natural processed
  • Note the Variables: time of day, the weather, the temperature, humidity- anything that may affect the roast.
  • Note whether you are working with a cold roaster (first roast of the day) or a warm roaster
  • Write down the profile you are planning to use (length and temperature of each stage of the roast)
  • And leave a space for what actually occurred. (refer to your variables for next time.)

Now begin? No, one more step. For safety reasons and best function of your roaster, no extension cords. If you have a home fire extinguisher, pull it out. If you have a box fan, use it to help clear smoke as it occurs. Open the windows, put your machine under the vented stove, and get ready to r-u-m-b-l-e. Once you've done this a few times you'll know what to expect. The first time, however, can be... exciting. The darker the roast the faster things occur and things can get away from you.

Beans Away

OK, now we are set. Load up your machine according to the machine's instructions (set the roast profiles if your machine has them.)

Weighing is preferred, but measuring by volume is fine too. Whatever you choose, do it the same way each time. Start the roast.

Note and write down any nuances you notice in the beans. Are the beans uniform or do they seem to be a blend of several different kinds of beans? Lots of chaff or little chaff? Ugly looking or perfectly formed? Are they big beans or little beans? More pointy or more round?

At first not much will seem to be happening. But then you will smell something like hay on a warm day. The beans will become a khaki color. As the beans darken, you are listening for two 'cracks.' The first crack is the sound created as water has escaped from the bean and the dry cell structure changes from the heat (usually about 12-18% of green bean weight is water). On some beans this first crack is very distinct; on others, it is barely audible. No big deal. You will learn to use other senses as you go along. You'll also notice that as coffee roasts it increases in size.

 Listening for Cracks

Note the time at which you hear the first crack (temperature too if your machine tells you.) It will sound like individual kernels of popcorn popping or twig breaking. Note the length of the roast at this point and write it down. How long did the first crack take to conclude? You might begin to get some smoke from the beans, depending on the bean and volume roasted.

 Sometime after the end of the first crack, you are going to wait and listen for the second crack. This crack sounds very different, much fainter, is shallower, and is more like a snap (some say that it resembles Rice Krispies) or more of a sizzle. You really have to listen for it. As you enter this second crack (note time and temperature), you are going to begin smelling a deeper roast, more smoke and the coffee's oils may begin migrating to the surface. The coffee will darken very quickly! and more smoke will be present.

 This is a good place to stop!

Especially if this is your first experience this is a good place to stop the roast. You've passed the first crack and are just beginning to hear the second crack. You're getting a bit of smoke but nothing billowing. Now is a good time to end this roast. Why? As coffee darkens just seconds become critical. It's better to practice what you've learned a few times and creep up on darker roasts than to make charcoal and try to pull back from that. And by the way... this batch will be the best thing you've tasted regardless of whether you could have gone darker with it. If you heard the second crack, and it looks like coffee, you're good. Stop the roast.

 Moving Towards French

OK, so you keep pouring heat into the coffee anyway. As the beans are becoming a very dark, oily brown. Your coffee is now losing some of its individual characteristics (flowers, citrus) and taking on more of a quality of the process (roasty, smoky.)

If you smell charcoal, then what you've made is charcoal, so pitch those beans and try again. But if you caught it in time maybe you've got a nice French Roast. Turn off the roaster's heating system and cool the beans. Note the time and temperature.

 When the machine is cooled, remove the chaff. Removing chaff from your machine is critical for two reasons: 

  • (1) Safety: Chaff is combustible and
  • (2) Good machine roasting and functioning.

Machines clogged with chaff are susceptible to fire and inefficient, inconsistent roasting. 

Note your observations -- What did you learn? Write it down. What would you do differently with the bean? Slow the roast down? Speed it up? Try to flatten the roast out? Keep in mind, these first sessions are all about learning your machine, not about making award winning coffee. Could you hear the cracks? How long did they each last? How long was it between the end of the first and the beginning of the second? What visible differences did you note at different points of the roast? 

Different Roasts Levels-

Let's take the time to learn different roasts levels and how to achieve them. Different roasters use different terms for the same level of roast but we will use the ones listed below as we try and reach five different levels: 

City Plus
Full City
Full City Plus
Vienna Roast
French Roast

 Your Second Roast and Beyond...

Keep in mind your roaster is warm and you will move to the first crack more quickly than your first roast. Did you clean out the chaff from the first roast? Make sure you clean the chaff from your machine after every roast because accumulated chaff can cause fires. Set your profiles, measure your coffee, and begin your roast, seeking a city plus roast. You can do this.

 City Plus
So what is a city plus? This is a relatively light roast. You'll see a pleasant coffee brown color, but probably not oils (until your coffee is on the way to being stale) A city plus maintains individual varietal traits and characteristics. It will be much lighter than 90% of the specialty coffees you find on the local upscale roasters' shelves. If you were first attracted to coffee by dark roasts from big chain stores, as you get to understand coffee you'll probably roast lighter and lighter approaching city plus. You really get the nuances, florals, fruits, brightness, and clearer tastes at lighter roasting levels that you're paying for.

 How to: The time of the first crack varies and lasts from as little as: 30seconds to a minute and a half, depending on the bean, the batch size, and the roaster. Keep your eye on the clock. You want to take the bean about 30 seconds beyond the end of the first crack. Pull the coffee at this point, cooling as needed. You have just finished your first city plus roast! Congratulations. Label it and set it aside.

 Full City
Start all over with your third roast, again listen for the cracks, let the roast go through its paces, and note the time from the end of the first crack until the second begins. As you become more experienced, you will want to learn how to stretch out this time between the end of the first crack and the beginning of your second crack. For a full city, catch this roast just prior to the second. Don't worry if you hear the start of the second crack, just make sure you pull the roast immediately. Label it.

 Full City plus
Next, try for a full city plus. Simple. The first 10 seconds (depending on your machine) of the second crack mark the full city plus roast level. Stop this roast, label it and set it aside.

 Vienna roast
When the second crack begins to rock and roll (20-30 seconds into the 2nd crack depending on your machine), you are in the Vienna roast level and your spouse or roommate is going to come to where you are roasting and ask if you are burning the house down. Oils begin to appear in spots throughout the roast. At this level, you really begin to lose the original character and the roast character becomes the pronounced element to your coffee.

 French roast
Ah, the roast that greets you in every upscale coffee shop across the country – the ubiquitous French roast. As you move your way through the Vienna level, watch your oils migrate to the surface. When the beans are good and shiny (about 50-60 seconds into the 2nd crack), turn on the cooling function and marvel at those oily bad boys. For me, the charred taste at the French roast level interferes with my ability to discern the varietal distinctions among coffees. But, if the French roast level is what you like, go for it! Some roasters will go even deeper and hit a Spanish roast which is darker yet. It truly tastes burnt and it an extremely thin coffee.

 The Tasting Moment
Now, let all those different roasts sit separately and apart from one another for 4-12 hours, minimally. You can store them in mason jars, but don't tighten them down as the CO2 needs to bleed off. Zip baggies are fine too. Once that time goes by, store your beans airtight, opening and closing immediately.


Timeis part of the recipe. Different coffees at different roasts will peak at different times according to what you like best. You'll be giving your coffee about a day to mellow. This is called "resting" or "degassing." What tastes only like coffee on day one may cause Nirvana on day three. Coffee is at its best anywhere from a day to a couple weeks at the most. You'll discover where each kind of coffee is perfect for you. While the variations are endless you will begin to discover what works best for you.

 There is more to all of this of course and it can't be stressed enough that different machines act differently. The smaller the batch the faster the roast, so discussing time frame and smoke volume is relative. Also, most roast level terms are a matter of opinion at best. Where one starts and one stop is difficult to say as is time frame on different machines.


You can see why roasting the same bean, time and time again is the way to learn. First, you understand the paces of your machine. Second, you now have five different roast levels that you can compare, one bean to another, and determine the varietal nuances of the bean at a variety of roast levels. Take your time and cup them, one after another. Do you notice that as your roast darkens, the roast characteristic begins to hide and take away from the coffee? Which roast level do your prefer? Why? Spend some time really paying attention to the cup. Take notes. 


Footnote:  Read and pay attention to your user's manual.  If at any time this information conflicts with your roasting machine, follow the manufacturer's directions.