When people are given the option of decaf coffee, they often think of the malty, stale flavors of “fake” or “damaged” coffee. I was actually one of those people. It was not until I had my first sip of a Swiss Water Processed decaf, that I truly understood how flavorful and similar a decaf could be to a non-decaf coffee. Weakly flavored decafs are often the result of a low-quality bean or faulty processing. When a specialty coffee is used, and the processing is handled attentively, then the original characteristics of the coffee should be maintained. Recently, I have received a few emails asking about the techniques of roasting decaffeinated coffee. It can be difficult answering questions about roasting, as every coffee is unique, but I have gathered a few tips from my experience that will help you get the best flavor out of your decaf beans.
Roasting decaf coffee can be a tricky process. Although the roasting progression is similar to a non-decaffeinated coffee, the exterior of the bean looks much darker throughout the entire roast. The Swiss Water decaf coffees that we offer are a darker shade of green pre-roasted and will have a darker, matte finish the duration of the roast. This difference in appearance is one of the main reasons decaf coffees are challenging to roast at first. For this reason, I do not distinguish the roast profile based on the color of the bean. Instead, I figure out the roast profile based on the 1st crack (which is softer than a non-decaf coffee bean) and the aroma. Once the first crack is finished, the coffee should lose some of its "bready" aromas and start smelling pungent and sweet. It took me a few roasts to understand the proper sights, cracks, and smells.
While roasting, you may find that the weight and density of the beans decrease. The reason for this is that the way decaf coffee holds moisture is altered due to the intense decaffeination process. This causes the beans to lose their moisture early in the roast and is the reason why the first cracks are often hard to distinguish. Decaf beans are fragile and should be treated with care. It is essential to begin the roast slowly with a gradual increase in temperature. As far as chaff goes, much of it is removed during the decaffeination process, so little chaff will collect in your roaster's chaff collector. Minimal clean-up is one of my favorite perks of roasting decaf coffees. Another thing to keep in mind is that oils tend to emerge a few days after roasting due to the more fragile structure of the beans. This is unavoidable and should not affect the overall flavor of the coffee.
Decaffeinated coffees tend to take a little bit longer to roast. When I am roasting a decaf at the same time as a non-decaf, I always end the roast of the decaf last. I aim to start the cool down process around 7 mins in, maybe 7.5 mins if it is a dark roast. Ultimately, a successful roast comes down to the flavor of the coffee. I highly recommend experimenting with your time to discover which roast profile you like best. Many adjustments will probably be made before you figure out your perfect cup. Coffee roasting is extremely subjective. What I prefer for a specific coffee may be entirely different for your taste palette. Roasting decaf coffees just require that you give them the same attention and care you would any other coffee.