An overview of our decafs and how to roast them
This decaf coffee fundamentals post sets out to provide background on the coffees we carry, as well as offer our roasting tips to get the most out of your decaf coffee.
When thinking about how to produce an excellent decaffeinated coffeeCoffee from which caffeine has been removed, either chemically or using water filtration. A variety of methods for decaffeination exist, but all operate on the same basic principle:... you have to first focus on the coffee before decaffeination. That’s right, we said “excellent decaf”, a term reserved for coffees you’d be hard-pressed to know are decaf at all.
We find these exceptions most with coffees we’ve sent off for decaffeination ourselves, lots that were selected for high cup quality to begin with. It turns out, the original quality of the green coffee
Green coffee refers to the processed seed of the coffee tree fruit. Coffee is a flowering shrub that produces fruit. The seeds of the fruit are processed, roasted,... before decaffeination is extremely important, surprise surprise.
We like to think of decaf drinkers as simply “coffee drinkers”, in that each person has their own preference for flavor, acidity
Acidity is a positive flavor attribute in coffee, also referred to as brightness or liveliness. It adds a brilliance to the cup, whereas low acid coffees can seem..., bodyAssociated with and sensed by mouthfeel, body is sense of weight and thickness of the brew, caused by the percentage of soluble solids in the cup, including all..., and all of the other sensory aspects of a coffee. This wasn’t top consideration with decafs of the past, flavor being secondary to inexpensive processingThe removal of the cherry and parchment from the coffee seed.: Coffee is either wet-processed (also called washed or wet-milled) or dry-processed (also called wild, natural or natural.... Plus, flavor matters little if in the end the coffee is poorly roasted, right?
The Swiss Water decaf method
The Swiss Water Process provides great clarity of flavor between the “before and after” decaffeination results. Because the volatile compounds are less disturbed with this method, the decaf should taste close to the original green coffee.
After each decaffeination run, the folks at Swiss Water sample roast and taste the before-and-after samples side by side, focusing primarily on any differences in cup qualities between the two.
Outside of cup quality, physical bean characteristics are also an important factor in selecting coffees for decaffeination. Swiss Water analyze all coffees for their moisture content (percentage of the bean that is water), water activity (the state of energy of the water in the bean), and densityThe density of a coffee bean is often taken as a sign of quality, as a more dense bean will roast more with a better dynamic. The density... (mass/volume) to make sure they can withstand processing.
These three aspects of green beans are an important trifecta for both roasters and decaffeinators alike, though Swiss may use the information differently. Knowing the relationship between those three physical characteristics gives some indicator as to whether or not a green coffee is viable for decaffeination. And as long as a coffee is fresh and stable, there are generally no problems with the decaffeination process.
Tips on Roasting Decaf Coffee
The classic decaf flavors that most people think of are the overwhelming maltiness, and in the worst cases, wet cardboard, but these flavors are generally the result of the original quality of the coffee itself or the intensityWe have a simple scale to rate intensity in our coffee reviews, from Mild to Bold. Low intensity does not mean low quality!: We have a simple scale... of the decaf processing. When the right coffee is selected and the process is carefully monitored, a good deal of the coffee’s volatile compounds that effect characteristics such as flavor and aroma
Aroma refers to sensations perceived by the olfactory bulb and conveyed to the brain; whether through the nose or "retro-nasally": The aromatics of a coffee greatly influence its... should survive. As Mike says, a really great decaf should resemble the original non-decaf coffee.
The same holds true for how the coffee behaves in the roaster. A well processed decaf EthiopiaEthiopia, formerly known as Abyssinia, or a coffee cultivar: Ethiopia, or more specifically the Empire under Haile Selassie, was known as Abyssinia. The name is Latin, derived from... should behave more or less like a regular Ethiopia, except that the decaffeination process does affect the coffee’s density. Because of this you want to be sensitive to how you use your energy input during the roast, especially during the initial drying stage and after the 1st crackAn audible popping sound heard during roasting. In coffee, one refers to "first crack" and "second crack," which come from two different classes of chemical reactions.: An audible... has really started to roll so it doesn’t get away from you.
A good rule of thumb is to try pulling back on heat as you near 1st snaps to minimize violent bean fracturing, and let the charge carry roast through to your final targeted roast development. On our Probat L-12 fully loaded (23 lb batch size), this means dropping the heat from 75% to 25% about 10 – 20 degrees before first cracks occur. This varies from one roaster to the next and will depend on batch size as well.
The major difference in roasting a decaf are the color change indicators. Color change is a big part of monitoring roast development in regular coffees, but because the decaffeination process alters the color of the raw coffee so drastically, the same color change indicators are no longer present.
One of the areas where this is the most problematic is at the very end of the roast. Decafs can appear much darker than what their actual roast levels are, and even begin to sweat some oils as the cellular structure is weaker from decaffeination. Even though a decaf may look dark, it might not actually be as dark as it looks since it started out a darker shade to begin with.
Most other physical and chemical changes are similar in decafs as in regular coffees, such as bean expansion, the 1st and 2nd cracks, as well as aroma indicators. The initial pops of 1st crack may be a little softer, but any well developed roast should have a distinctive finishSimilar to aftertaste, but it refers to the impression as the coffee leaves the palate. Aftertaste is the sensations gathered after the coffee has left the mouth. We... to 1st crack.
The roast aromas during and after the 1st crack are some of the most telling indicators of roast development during this period. You should move past the cereal and bread-like aromas and begin to smell some pungency, almost vinegarA defective flavor taint in coffee, resulting perhaps from poor processing, fermentation, sanitation.: Vinegar-like qualities are a defective flavor taint in coffee, resulting perhaps from poor processing, fermentation,...-like aromas, but with sweetnessSweetness is an important positive quality in fine coffees, and is one of five basic tastes: Sour, Sweet, Salty, Bitter, Savory (Umami). In coffee, sweetness is a highly... to it.
Timing past the end of 1st crack is also crucial here. Use it along with your aromas to tell you when the coffee has reached your desired roast target. If you roast the regular version of that coffee to an end point of 20 seconds after the end of first crackFirst crack in one of two distinct heat-induced pyrolytic reactions in coffee. It is distinguished by a cracking or popping sound in the coffee, and occurs between 390..., then do the same with the decaf version, and adjust from there.
Just because the coffee color is darker and some oils may be present, this doesn’t mean that you’ve engaged in dry distillation or are developing roasty flavors. This is one more reason why when we talk about roast level that the conversation has to be about more than just roast color.
Read more about the Swiss Water Process HERE
More tips and tricks on roasting decafs can be found HERE
Update of an 2013 article by Chris Schooley and Mike Strumph
