Roasted Coffee

It is impossible to make good coffee using poor green components. In addition, poor roasting techniques have ruined potentially excellent coffee. Roasting is a process that is technically challlenging and difficult to completely replicate. As a result, there is a wide variety of interpretations of what constitutes a properly roasted product.

The most important physical standards for the testing of roasted coffee are:

The roast degree will determine what flavor component of the individual coffee is emphasized and is a primary determinant of the flavor profile.

More acidic coffees may maintain their acidity better at darker roasts, while those that naturally have heavier body may be able to maintain that body through darker roasts. Some origin flavors can be more clearly perceived when the roast is lighter (more acidic), while some are obscured at the same level of roast.

Two measurements can be taken using the Agtron, the whole bean color and the ground bean color. The ground roast color will always be a number greater than the whole bean roast number. The difference between these will reflect the evenness of roast. If the difference is too great there is a chance that "tipping" (burned ends of the beans) has occurred resulting in a charred flavor or the inner portions of the bean have not been completely roasted, resulting in an astringent flavor. If the difference is too small the coffee may tend to taste bland and uninteresting.

It may be necessary during the crop year to change the Agtron standard slightly. Past crop coffee, which has lost significant acidity and moisture, may taste a bit better if the roast is a little lighter, while a slightly darker roast may eliminate some new crop taste and add body.

The degree of roast is one of the primary decisions to be made in determining the flavor profile of the coffee. Coffee Analysts can assist the roaster in bringing the best out of the coffee and assist the retailer in developing specifications for the desired flavor profile and managing that profile throughout the crop year.

Measurement of moisture content will assist in predicting shelf life. Coffee with too much moisture will stale quicker, even if its packaging has been vacuum-sealed or nitrogen flushed. Too much moisture can be the result of overquenching during roasting or having come into contact with humidity for extended periods of time.

The relative fineness or coarseness of grind will determine how quickly a coffee’s flavor will extract during brewing. The relative coarseness or fineness of grind must be appropriate for the brewing equipment and size of batch being produced.

The grind is measured by means of sieve analysis. Grinders go out of adjustment through use and wear, and grinder burrs should be replaced regularly according to manufacturers’ instructions.

For more information on Coffee Analysts’ services, call TOLL FREE 1.800.375.3398, or send an email to info@coffeeanalysts.com.