Some call it body, but that is an illusive quality to describe without an understanding of how to judge body. Well it’s all about mouthfeel.
The body sensation of a coffee beverage is affected by two main factors:
- The coffee-to-water ratio;
- too much water = thin, bland, flat
- too little water = sharp, astringent.
- The amount of soluble sugars and fats that are released by the coffee into the water during the brewing process.
Coffee is a colloidal suspension. Of the 800 +/- different chemical compounds in roasted coffee, some are water-soluble and some are oil-soluble. Brewing extracts both, but oil-soluble compounds tend to take longer to extract than the water-soluble compounds in the grinds, and the oil-solubles tend to be on the bitter spectrum. Thus a 3-4 minute brew cycle will be sweeter and more pleasant than an 8 minute cycle.
Now, just for a practical application of the mouthfeel, let’s use this progression: water, skim milk, low fat milk, 2% milk, whole milk, half-and-half, heavy cream. In coffee, drip method preparation might approach 2% milk, while espresso may give you a similar mouthfeel as half-and-half. Finally, roast color does have an important influence on the body of a coffee, regardless of brew method. The key: the lighter the roast, the greater the body. The darker the roast, the thinner the mouth-feel. The importance of body relates to flavor retention or finish. The greater the body, the longer the finish.