Coffee Analysts » brewing

Optimal Coffee Brewing Explained

Staff — Tue, 17 May 2011 14:00:00 +0000

When coffee is brewed correctly, there is truly nothing like it. You do a double-take, look incredulously at the cup in your hand and say, “man … that’s GOOD.”

But in order for the coffee to come out just right, the correct brew parameters must be in place: water quality, water-to-coffee ratio, water temperature, and grind. When brewed correctly, the coffee’s best flavors are released quickly, and bitterness will be present, but it will be perceived as more of an aftertaste or “finish.” Cutting off the extraction at a certain point can control the amount of bitterness.

The ideal cup

However, when coffee is brewed poorly, you can be left with a weak or bitter or *gulp* weak AND bitter cup of coffee.

Water Not Hot Enough

If the water is less than 190º F., the best flavors are not extracted, but the more soluble bitter flavors will be. The product will taste weak and bitter.

Water not hot enough will lead to bitter, weak coffee

Water Too Hot

If the water is above 205ºF, all soluble material, including less desirable material, is quickly extracted, resulting in a strong bitter cup.

Water over 205F results in strong, bitter coffee

Coffee Grind Too Fine

When the coffee is ground too fine (particle sizes too small), the best flavor is quickly extracted. More of the bitter flavors will also emerge after the better flavors have been washed out.

Too fine of grind leads to bitter coffee

Grind Too Coarse

When the coffee is ground too coarse (particle sizes too large), the brewing process proceeds slowly. The best flavors are not dominant and the cup will taste weak and somewhat bitter or astringent.

Too coarse of grind results in weak coffee

Brewing Coffee – Testing and Analysis

Staff — Wed, 27 Apr 2011 14:28:40 +0000

Any coffee, no matter of what quality, can be affected dramatically at the stage of brewing. Brewing is a chemical reaction between hot water and coffee. According to work done by the Coffee Brewing Center, while roasted ground coffee is about 30% soluble by weight, only 18-22% of that soluble material results in desirable coffee flavor. This material must be present in a certain concentration to be best appreciated. For more details on ideal conditions for producing a satisfying cup, see the SCAA website.

Important Considerations

Most parameters affecting brewed coffee are those which must be adjusted (and measured) on site. Sensory evaluation must be performed when the coffee is freshly brewed to be evaluated fairly.

However, some clues as to the quality of brewed product can be obtained through certain measurements.

Perhaps the most important (and often ignored) factor in brewing is water quality. Water makes up 98-99% of the finished beverage and any off-flavors will ruin a cup of coffee. The presence or absence of certain chemicals will inhibit or allow the best flavor to emerge.

Water Quality

Premium water filtration system

As brewed coffee is 98-99% water, the quality of that ingredient dramatically affects the finished product.

Two parameters are important in measuring brewed coffee: the quality of flavor and the strength of flavor. The strength of flavor, the amount of solids that have actually been extracted, can be measured by the use of a Total Dissolved Solids (TDS) meter. This information can be extrapolated to determine the flavor quality if the water to coffee ratio is known. Testing of pH can give additional clues as to the quality of the brew.

It is especially important for retailers of brewed coffee with multiple locations to produce coffee beverages that are consistent at all locations. One can use these tests to determine how closely the different locations match up, and then create a coffee specification program to ensure consistent quality.

How to Make the Ultimate Cup of Coffee

Christine Hibma — Sun, 09 May 2010 15:09:15 +0000