Suppose you decided to roast your own coffee. Using the advice and tips on this page, you will be able to prepare for your first roast.  

To make great coffee, you need more than quality beans. A fulfilling experience requires careful attention to every detail. Each step is therefore important.

First things first.

Start by getting hold of a 5 pound bag of Colombian, Costa Rican, or Guatemalan beans, because these varieties tolerate heat well. They are great beans for learning to roast, and will provide a chance to produce world class coffee without worrying about the exact process for the first few roasts.

As you’re exploring your roasting methods, let yourself learn as you go. You will immediately know that you're on the right track when you taste your Costa Rican, Colombian, or Guatemalan beans.

What can you do to prepare?

When picking up beans, make sure you have oven mitt gloves handy. If you have a kitchen window or outside vent, put the shelf closer! Recirculation systems in kitchens are not recommended.  

You should decide which outlet you plan to use and dedicate it to the roasting process. You don't want your voltage changing while you're using your machine.

Bring a scale, a measuring cup, and a colander to the table. To collect chaff that is blown about, keep a towel or brush nearby. Chaff is a papery-like material that falls off roasted beans during cleaning. Some beans have more, some have none. Most home machines contain chaff filters.

Get ready to take notes.

A home roaster needs notes if they wish to succeed. It is the worst thing that can happen to you if you roast a perfect batch of coffee and don't retain the roasting profiles or pull dates for the beans and are unable to duplicate it.  

Design a template you can use that includes the following details:

• Country, region, state, whatever identifies the beans
• Date your beans were purchased
• Date your beans were roasted
• Variety of beans (bourbon, typical, etc.)
• Wet-processed, dry processed, natural processed
• Varying factors: temperature, humidity, weather, time of day (anything else that may affect the roast).
• Roasting cold (first roast of the day) or roasting warm
• The roasting profile you intend to use (length and temperature for each stage)
• Notes after the roast/brew

While this may seem like a lot of information to keep track of, it’s important to note that good roasters use the “scientific method” which tracks every single variable that could impact the quality of the roast.  

There is one more step before you begin.

To ensure safety and functionality of your roaster, do NOT use extension cords. Pull out your home fire extinguisher if you have it, grab a box fan to clear smoke as it occurs, open the windows, and put your machine under your vented stove.

Things can get away from you very quickly (especially during darker roasts) so you need to be as prepared as possible in the case of an emergency.

Roasting Coffee

We consume roasted coffee products after roasting green coffee beans, which changes their chemical and physical properties. By roasting green coffee beans, the characteristic flavor of coffee is produced. 

A roaster machine roasts green coffee beans in a way that maximizes the yield of roasted coffee products, while minimizing pre-produced useful coffee ingredients, after production and dissociation reactions have occurred on the coffee bean.

Factors That Affect Roasted Bean Quality

A bean's ripeness is determined by its processing procedure after harvesting and drying it, then hulling the beans to separate the seeds from the parchments. 

Green beans should be classified into their respective categories (you will know these as arabicas and robustas), and the density, the size, the moisture content, and storage period (new crop, old crop, past crop) will be taken into account during processing and roasted.

It is also important to note the type of roaster. You can select various roasting parameters, such as the heat source (gas, electricity), the heat transfer medium (conductance, conductive), and the heating rates (high, slow, manual).

Here's a typical roasting example.

During roasting, the chemical reactions in which the coffee beans are involved are the most important part of the process. Aromatic components, acids, and other flavor components are produced, balanced, or altered by these chemical reactions to give coffee its perfect taste, acidity, aftertaste, and body.

Maillard Reaction

Roasted coffee flavor and color are developed as a result of the Maillard reaction. Aroma and flavor compounds are formed by reacting carbonyl groups in sucrose with amino groups in amino acids and proteins at temperatures of 150° - 200° C. Maillard chemistry produces hundreds of coffee flavor compounds. The complexity of chemical reactions with many steps has left so many controversies unresolved despite the importance of this reaction.

Caramelization

When sugar in coffee caramelizes between 170° and 200° C, aromatic and acidic compounds are released. The sour compounds will not degrade if you roast the coffee lightly, as most of the sucrose is converted to caramelized compounds. 

This can be seen in the Maillard reaction, where caramelization occurs roughly at the same temperatures. In addition to this, because sucrose is used as raw starting material in both reactions, it is a competitive reaction as well as occurring simultaneously.

First Crack

A bean expands and cracks when the water inside releases vapor at around 205° C (both physically and audibly). In the stages before first cracking, bean turns from green to light brown. After this step, light roasts are done.

Pyrolysis

A thermal decomposition occurs when materials are heated to high temperatures in an inert environment, such as a vacuum gas. Carbon dioxide is released into the atmosphere when a chemical reaction occurs within a bean at approximately 220° C. Approximately 13% of the bean's weight is lost and the color turns medium brown.

Stop here!

For those starting out, this is an excellent place to stop. It's just beginning to sound like the second crack after you've passed the first crack. However, you only see a small amount of smoke. During the darkening process, just seconds are critical. I recommend practicing your darker roasts a few times rather than trying to pull back after making charcoal.

 What did you learn from this experience? Take notes. In your opinion, how might the bean be improved? All things to consider on your future roasts ─ they can only get better from here!