Gauging quality of Coffee Arabica beans: Sticks and stones – and quakers?

Last time we talked a little about the origin of coffee beans, and how they’re used in mass production of coffee versus what we do, which is small-batch roasting.

In recent years there’s been a shift among the more “refined” canned coffee companies to use Arabica beans. However, as with any food, there are grades of quality.

Many countries classify and compare coffee beans by using a “screen size” sorting system, which is exactly what it sounds like. Coffee beans are sifted through screens which allows for uniformity. That’s where gradation in quality comes in.

For instance, a glass of freshly squeezed orange juice sounds wonderful, but if it is made out of the worst, deformed, sour oranges, it is going to taste pretty bad. Same with coffee.

There are six areas that are assessed when tasting coffee: aroma, acidity, body, flavor balance and finish. Aroma is how the coffee smells. It is good to smell both the dry and wet grounds. Acidity is the bright tangy quality found in coffee, similar to the bright quality of a tomato. Body is the weight of coffee in the mouth; how heavy or light. Flavor is how the coffee tastes.  Balance is how all the components work together. Finish is how your mouth feels after you swallow the coffee. Is there a residual flavor or texture? When assessing coffee, we use the Specialty Coffee Association of America’s (SCAA) Cupping Protocol. By using this protocol, we eliminate multiple variables so all we taste is the coffee.

Of course, before we get around to the tasting, the crucial grading, processing and roasting of the beans has to happen.

Specialty-grade Arabica coffee is grown in every continent except Antarctica.  It is grown in a specified zone on either side of the Equator, between the Tropics of Cancer and Capricorn.  In fact, there are two main growing regions and climates.

The first region is in subtropical regions that have distinct rainy and dry seasons.  Mexico, Jamaica, Zimbabwe, and regions of Brazil are examples of countries with this type of climate.

The second type of growing region is the equatorial region at altitudes of 3,600-6,000 feet.  Frequent rainfall results in two harvests per season.  Kenya, Colombia and Ethiopia have this type of climate.

As with wine, the climate, type of soil, nutrients in the soil, and air quality do impart distinct characteristics to the beans. Coffee likes volcanic soil, and many of the growing regions have active volcanos.

There are many cultivars of the Arabica species.  Some are heirloom, like the Bourbon and Typica, and many are now hybrids based on the heirlooms that have changed with region, altitude and grafting. The varieties are chosen by growers based on disease resistance, production yields, and regional track record. The trees are evergreen and yield two crops per growing season unlike our fruit trees, which lose leaves in winter,

It is important to only pick the red, ripe cherries to get the best tasting coffee. The natural sugars have properly developed when the cherries are ripe. They develop slower at higher elevation, imparting more sweetness to the bean as they mature which means altitude is an important factor in the sweetness of the bean.

There are five grades of coffee – 1. Specialty Grade Green Coffee; 2. Premium Grade Coffee; 3. Exchange Grade Coffee; 4. Below Standard Grade Coffee; and 5. Off-Grade Coffee. Unlike the lower grades of coffee beans, Specialty Grade coffee beans may not contain any debris, including sticks, cherry stones or  “quakers” – that is, unripened coffee beans, which is considered a defect. Lower grades are allowed an increasing number of defects.

Next time, we’ll talk more specifically about how coffee is graded. Then we’ll look at how coffee goes from bean to your cup.

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