Coffee Roasters

No matter how fine the conditions, plentiful the harvest, and neatly picked and hulled and dried the fruit, the best coffee beans in the world don't stand a chance if the roasting goes awry. Roasters start with pale green beans--which, left alone, stay fresh for a full year or two--and turn out any number of subtle variations. Roasted beans remain fresh for several days to perhaps a week. The roasting process is therefore touted as part science and part art, and so it is.

The basic parameters for roasting, whether it is done commercially or at home, involve temperature. At the low end, it's critical that the temperature rises above 400° F. At the higher end, it's equally critical that it does not exceed perhaps 460° F.

At 390° F the color is still pale, the flavor oils aren't cooked enough to peak, the coffee tastes sour or grassy, and there is little to no characteristic coffee aroma. At the 480° F range the beans turn black, the oils burn, and the coffee will taste thin and charred. Baking beans at too low of a temperature or for too long, or scorching their exteriors, are the comparable excesses in home roasting.

Just as certain phrases are used to describe the taste of coffee, another set is used in relation to roasting. Those that apply to taste are acidity, body, depth, aroma, and complexity. Those that apply to roasting are sweetness, pungency, and what is referred to as either roast or bittersweetness. Breadiness refers to those not roasted enough, and baked to those too long in the roaster at too low a temperature.

Home Coffee Roasting Methods

There are four commonly accepted ways to home roast coffee beans. If you prefer a bright and acidity brew, the hot air popcorn poppers will serve you will. If you favor a heavier body and rounder taste, the traditional stove-top popcorn popper is ideal in allowing the roasting smoke to envelop the beans as they roast. Gas ovens produce a full-bodied coffee, low in acidity, and interesting complexity. Electric convection ovens, on the other hand, yield low-acid, rather full-bodied, and understated beans.