Fluid Bed vs. Drum - What's the Difference?

I started roasting 20+ years ago and have learned a lot along the way. I've used both fluid bed style and the drum style roasters. Both have produced great, as well as horrible results. It's not usually the machine's fault; it's operator error!

I locked in on fluid bed roasting because I like the taste of the coffee it produces. There are plenty of studies that highlight the advantages and disadvantages of both fluid bed and drum roasting. For me, fluid bed roasting produces a clean, bright cup with a very distinct flavor profile.

Since more than 90% of the coffee roasted today is on a drum roaster, the taste has become the "standard" for many people. The cup features more smokey, charred notes such as brown butter or caramel. Taken to the extreme, the exterior of the bean turns black and the coffee takes on a charcoal taste. Some high capacity chains leverage this approach so that the coffee tastes the same from batch to batch.

Being a micro-roaster, my approach is less scientific and more artistic. I often say, "The beans will tell you when they are done roasting." And they do. I have a good idea of how long it will take to roast a batch but each one is unique. The roast is affected by ambient temperature, humidity, and other environmental factors. In addition, no two lots of coffee taste the same.

I remember roasting some Mexican coffee that was a family favorite. Every year, I would reorder the same coffee when it became available. Yet, the taste was never the same as the first year. Sure, the roast was good, but each was unique.

For commercial roasters, the nuances are problematic. For me, they are an opportunity to provide my customers something new and different. The fluid bed roaster allows me to achieve my goal of delighting customers with the best possible coffees.

So, in the end, you choose the coffee you like. Most will be from drum roasters (and they produce some excellent coffee). Enjoy it. But give fluid bed coffee a try. It will open your eyes to a new taste experience.

Just remember... keep it fresh, brew it right!