Coffee brewing masquerades as a simple process, when in reality it is a very complex interaction of many variables, all of which must be tightly regulated. Coffee gets most of its flavor from the great variety of chemical compounds released when the ground particles make contact with water. Under normal circumstances, water extracts roughly 80 […]
Category: Brewing Fundamentals
The Brewing Process
Aroma + Taste = Flavor Some of the chemical compounds in coffee evaporate easily and are responsible for the brew’s aroma. Others aren’t so volatile and are the source of the brew’s taste. The combination of aroma plus taste constitutes coffee’s flavor. Further, there are the insoluble compounds – the ones that don’t break down […]
Grinding Essentials
If you took one whole coffee bean and placed it in water and subjected it to heat and agitation, at some point the coffee flavoring material would be extracted. But this method would take much too long to be practical. Now, consider taking one whole coffee bean and splitting it in half. The water now […]
Time, Temperature & Turbulence
Time’s Relationship to Extraction Hot water removes flavoring solubles effectively and rapidly. At the beginning of the brew cycle, the resulting extract appears dense and dark caramel in color. As extraction continues, the extract becomes less concentrated and lighter in color. Near the end of the brew cycle, the extract is pale and appears almost […]
Filtering Devices
What’s the purpose of filtering? To separate the grounds from the coffee beverage after the brewing cycle has concluded. Filtering coffee usually consists of two parts: 1) the structure of the device and a shape that contains the bed of coffee grounds as well as the water that passes through them; and 2) the filter […]
Holding & Serving Coffee
Holding Temperature The shelf life of green, unroasted coffee is usually expressed in years – for example, new crop, current crop and past crop. Once it has been roasted, the shelf life is measured in days. The stale flavors in coffee can become detectable as early as 4 days after roast, or as late as […]
Analysis of the Finished Brew
When coffee is brewed, hot water removes most of the water-soluble material by a process that combines dissolving and extracting. The water first penetrates the grounds, dissolves some of the chemical components it encounters, makes a solution of these materials, and then exits the grounds to produce the familiar beverage. We measure the solubles yield […]
Water Quality Standards
Water (H2O) is comprised of one oxygen and two hydrogen molecules, and the bonds between and among them lead it to be a unique and fascinating biological molecule. As we know, depending on the coffee beverage (espresso versus drip-based) water can contribute 94-98% of the ‘coffee’ beverage as we consume it (Illy and Viani 2005). […]