What is a Micro Artisan Roaster ?
Roasting coffee is both an art and a science. Throughout the centuries, people have quested for the “perfect roast”. We have employed everything from pan roasting over open flames to much more sophisticated equipment such as the modern drum roaster – all to bring coffee beans to their fullest potential. As any good roaster knows, coffee is a temperamental food that requires perseverance and creativity to reveal each variety’s ideal roast. Fortunately for those of us who have a passion for coffee, technology has evolved to help us with this pursuit. At Joe Bean, we are artisan micro roasters who use a drum roaster and a profiling system to produce exceptional coffee.
So what does all that really mean?
As it implies, micro roasters roast in small batches, similar in concept to the microbreweries that have emerged in the last few years. The advantage of small batch roasting is control—the control necessary for an artisan micro roaster to be exact with each attribute of a coffee’s taste: acidity, body, flavor and aroma.
The term artisan roaster implies much more than the creativity of the roaster. It is really a commitment to a creative process. Every coffee we roast is cupped until we feel that its coffee’s attributes are perfect. This is a time-consuming process—sometimes taking months of experimentation to bring out a particular coffee’s rich qualities.
Although roasting coffee can be done a variety of ways, including in a pan over an open flame, commercial roasters generally use one of two types of machines: a drum roaster or a hot air roaster. In a hot air roaster, coffee will literally float on a bed of hot air that roasts the coffee, similar to a popcorn popper. In a drum roaster a metal drum is rotated over a flame, or some other source of heat. At the same time, air is drawn from the flames (or other source of heat) and passed through the drum itself. Hot air roasters tend to have a shorter roasting time, usually around 6 minutes per batch, as compared to drum roasters, which have an average roast time of 10 – 15 minutes. At Joe Bean, we use a drum roaster because we believe 6 minutes is not sufficient time to develop each attribute of the coffee bean.
How coffee is roasted greatly influences its flavor. The final temperature is the most important influencer of a coffee’s flavor. Generally, a coffee will be roasted somewhere between 415°-460°, 415° being right at the edge of a light roast, 425° being right in the middle of a medium roast, and 460° being a dark (or Italian) roast. As the beans reach a higher temperature, sugars become more developed and different chemical reactions occur.
Time is the second most important factor in roasting. The greatest effect of time is felt in the amount of organic acids, and the number of chemical reactions. Organic acids affect the acidity (naturally) as well as the aroma of the coffee. There are several different acids in coffee, the largest being Chlorogenic, but also included are Quinic, Citrus, Acetic, Lactic, Malic, and Phosphoric. Each of these acids will develop as a result of chemical reactions during roasting as well as naturally residing in the coffee.
Because these factors are so important, we use a profile roasting system—a method of controlling the rate of heat transferred into the coffee during the roasting process, with the goal of optimizing flavor and consistency. The profile roasting system involves bean probes, environmental probes and a computer program that helps us analyze the coffee’s temperature progress over time. If the progression is constant, forming a straight line when graphed, the coffee will taste different than that yielded by a roast cycle that has a curved graph. What is important here is how long the coffee is held at certain temperatures, because different chemical reactions occur at specific temperatures. For instance, a coffee held at 370° will develop more of a certain chemical (as a result of the reaction) versus a coffee that is roasted in a straight line. Profiling is the most difficult part of determining how to roast a coffee.
Each type of green (unroasted) coffee has its own unique roast profile. It is the roaster’s job to bring out the best in each coffee. Since green coffees from
different regions possess unique qualities, each profile must be developed individually. Once we have created each profile, we faithfully follow it to ensure consistency and quality in future roasts.
After coffee is roasted, the beans are still developing. They emit generous amounts of CO2 gas. Coffee must sit 18 hours before it is ground or consumed to ensure that the majority of CO2 is released and that the flavor has fully matured. During this time the coffee is packaged into foil bags with one-way air valves. The one-way valve allows CO2 to escape, but prevents oxygen, which can be damaging to the coffee, from entering.
Between growing quality coffee, profile roasting each variety, and packaging in a timely manner, there is an enormous amount of effort and knowledge necessary for producing a good cup of coffee. But, it does not end here. Even top quality coffee can be
brewed incorrectly thus detracting from the coffee’s flavor. Therefore, it is important to understand the properties of brewing coffee to make sure you get the most out of your specialty coffee investment.