Coffee roasting is an art and a science at the same time. The art starts at the cupping table. Where a professional Barista can make his decision for a roast style and profile based on factors of aroma, taste and peak flavor. The science aspect includes your level of understanding of the chemical reactions inside the coffee bean and the technical know how about roasting technology and equipment.
As a roaster, it is very important that we taste the coffees we are making—it’s the only way to understand how to roast the coffee. When we roast, we’re using all our senses, especially the nose. The way a coffee smells while it’s roasting will help explain what it might taste like. The coffees are always changing as well, from the size of a batch we roast, to the way it changes with time. It all depends on the season as well. We forget coffee is a raw product. We want characteristics of that country to really shine in the coffee.
Artisan coffees are created when the grower is willing to take the extra steps to ensure quality results, and the roaster is willing to pay the premium price necessary to support quality.
Artisan coffees evolve from sustainable farm practices which include a respect for the habitat and good production values at each stage: meticulous selection, milling and drying of the raw hand-picked coffee at origin, and careful crafting of the coffee into a finished form by the roaster.
Artisan coffee roasting is a marriage of science and sensibility. The science involves controlling the roasting medium via the roasters knowledge of the roasting machine, the raw product (green beans) and the roaster’s visual and tasting sensibility.
From a technical perspective, a great cup of coffee starts at the farm level with top-grade, high quality, expertly processed coffee beans. As coffee roasters, once we’ve sourced excellent coffee, it is our job to roast it to a profile that highlights all of the best natural qualities of that specific coffee’s growing region, species, etc. Once you’ve got all of that, fresh from the roaster, it comes down to filtered water at proper temperature, proper grind of the coffee, and appropriate extraction time (exposure of ground coffee to water).
The overall roasting process needs heat to progress and this is transferred from the heating element in the roaster to the beans during the roasting process. There are three main forms of heat transfer that we’re concerned with in drum roasting; convection, conduction, and radiation. Convection heat is heat moved by a liquid or a gas and in the case of a drum roaster, we’re most concerned with heat moved by gasses present in the roaster, i.e. the air in the roaster. Conduction heat is transferred through direct physical contact. Heat travels from higher gradients to lower gradients and can happen from bean-to-bean and drum-to-bean contact. Radiated heat is the most complicated of the three forms of heat transfer. The drum will radiate heat to the air and the air will transfer heat to the bean. None of the heat transfer forms are independent of one-another.
Artisan roasting allows the user to determine roast profiles from batch to batch as opposed to following a general recipe every time. Each bean is different and each batch will roast slightly differently.
Artisan roasters, in addition to using accurate gauges, timers, thermocouples, etc, also use all their senses when following the development of a roast — observing the color, the smell, the sound, and the gradual change in shape of the beans. Through extended experience with his machine and his coffee, the artisan roaster develops an intimate knowledge of how each bean behaves and he can make subtle adjustments during the roasting process so as to maximize quality.
Automatic roasting systems are less prone to the introduction of human error. They can work very well if the automated profile is worked out intelligently and verified on the cupping table. Even the best automated profile will have to be checked and re-checked as time goes by, because subtle changes in the beans will affect how the end quality results.
Each coffee growing region varies greatly due to variables such soil conditions, elevation, and rainfall. Additionally, processing methods (such as wet or dry) affect the bean. Consequently, each bean varies in size, moisture content, density, etc. Therefore, each coffee must be roasted individually to maximize its unique flavor.
The coffee roasting process allows you to create a personal and signature taste that can distinguish your coffee beans from other coffee beans in the marketplace.
Mulatoz’s Roaster is able to regulate the effects of roast variables such as heat, and bean temperature over time. As a result, factors for taste is defined to find the perfect "Peak of Flavor" for each roasted coffee and supply truly fresh, grade one coffee to fine restaurants, coffee houses and catering companies.