How We Roast Our Coffee
Richard Steffensen, the roast master at Strictly Organic Coffee Company has 16 years of coffee roasting experience. When he started his own business, he chose to use a fluid bed air roaster. There are many differences between the two main types of roasters and here are a few of the main ones that led us to prefer air roasting over drum roasting.
1. The longer and hotter the beans are roasted, the more flavor escapes.
A commercial drum roaster can take 15, 20 or more minutes to roast a batch of green beans. The same batch size of green beans can be roasted in 6 to 8 minutes in a commercial air roaster. The longer the beans are subjected to roasting temperatures, the more flavors and aromas volatilize away.
2. Air Roasters provide consistent temperatures to all of the beans in a batch.
Fluid bed air roasters are called “fluid” because of the fluidity of movement the beans are allowed, not because water is involved. Our current air roaster does not use one drop of water in either the roasting or cooling process. No water soaking is involved in any air roaster we have heard of. In larger fluid bed air roasters, a 45-second water spray is recommended at the end of the roasting cycle to bring the temperature of the roasted beans down more quickly. Since the spray takes place in the roasting chamber while the beans are still being circulated at a temperature of 400 degrees F or more, virtually all of the water flashes immediately to steam, which is forced out of the roasting chamber through the venting system.
Hot air coffee roasters are a lot like hot air popcorn poppers. The beans float on a bed of air in the roasting chamber, allowing all of the beans to be heated to exactly the same temperature at exactly the same time. Degree of temperature directly correlates to degree of roast.
In drum roasters, the beans sit in the drum and are stirred with a mechanical arm. Depending on whether they are directly on the drum surface or in the middle or top of the batch of beans, the coffee beans reach the optimum temperature and ultimately the “second crack” at different times, resulting in an inconsistent roast. Roasting can be uneven and some beans that remain in direct contact with the cylinder too long are scorched. This is a much less controlled method.
3. Drum Roasters trap and burn coffee bean chaff.
In a drum roaster, much of the chaff that comes off of the roasting coffee beans remains in with the beans throughout the roast. The chaff burns and smokes, causing a burnt flavor, especially in dark roasting.
In an air roaster, the chaff rises into the cyclone and is deposited into the chaff collector as it comes off of the beans. It does not burn and damage the flavor.
4. Air Roasting is easy to control and duplicate.
Air roasting provides the roaster exact control over each batch of coffee. Beans are roasted “to temperature," in hot air roasting, rather than "to color," as with drum roasting. Color matching is much more subjective. When each batch of coffee is roasted to precisely the same temperature, roasters are better able to yield coffee batches that are consistent in color, flavor, undertones and aroma. The degree of roast is known at all times and is easy to duplicate accurately. Drum roasting relies more heavily on the experience and opinion of the individual roaster. Batches are not as easy to duplicate.
These are the main reasons one would choose an air roaster over a drum roaster. The drum vs. air argument has been going on for a long time. Most consumers do not know the difference. They just know what they like and as the average person’s palette is becoming more educated, they are turning away from the traditional burnt taste of drum roasting.
Everyday we hear that our coffee is the best coffee someone has ever had. We do not take that compliment lightly. Since we are not the only local coffee roaster, we cannot put that compliment down to freshness alone. One of the major factors is air roasting; it affords us amazing consistency and control and allows the flavors of the beans to speak for themselves.