Optimizing the Roast of Decaffeinated Coffee

By Aaron Braun, Swiss Water Decaffeinated Coffee Company. Thanks to Swiss Water Decaf for this article.

In 2017, decaffeinated coffee consumption grew faster than that of non-decaffeinated coffee, especially in the restaurant and café segment. According to various research, the largest past-week consumers of decaffeinated coffee are actually young – 18-24 years old; a trend consistent in Canada and in Western Europe¹. As younger consumers are also the heaviest drinkers of specialty coffee and it appears that they move fluidly between regular and decaffeinated coffee, it’s clear that a high-quality, great-tasting decaf coffee is more critical than ever for any specialty roaster or retailer.

There can be a lot of trepidation and misinformation about roasting decaf, and I often get asked “How do I roast decaf?” This is a difficult question to answer as no two coffees are the same, so it’s impossible to develop a full list of ‘roasting rules’ for decaf.  Never-the-less, here are a few tips to help you begin to get the most out of your decaf offerings.

TIP #1 – DECAF LOOKS DIFFERENT. THAT’S OK.

It’s important to remember that your decaf offerings aren’t going to look the same as non-decaffeinated coffee – green or roasted – no matter the decaffeination method. These differences in appearance from non-decaffeinated coffee can be challenging at first when roasting, so it’s crucial to know what you’re getting into and to get accustomed to how that appearance will change as the roast progresses.

For instance, Swiss Water® processed coffee starts out a darker shade of green and has a matte finish. It will follow a similar roast progression to non-decaffeinated coffee and the exterior of the bean will maintain a darker color through the entire roast. Keeping this in mind, we have to move past the roasted whole bean color to give us an indication of roast development instead looking for other visual indicators such as internal ground color or surface texture.

However, texture can also be deceiving. Coffees decaffeinated with chemical methods, such as Ethyl Acetate or Methylene Chloride can develop a shiny sheen at very light roast levels, while water processed decafs can remain matte even with deep development. Getting the most out of your decaf is all about learning about and embracing these differences and not letting a different visual appearance negatively influence your intended roast style.

Every roaster handles this differently, but here’s how Rob Hoos, Director of Coffee for Nossa Familia and author of Modulating the Flavour Profile of Coffee, handles the different visual appearance of decaf:

“Typically, until first crack I have to rely more on my thermocouple than the actual visual appearance because the browning has already been a bit jump-started. So I will use my thermocouple, smell for first crack (as well as listen, but for me smell takes precedence) and then aim for reasonable development and end temperatures.”

Ultimately, how the coffee looks when roasted should be of secondary concern to how it tastes in the cup.  Set aside the bias and put that coffee on your cupping table. Let taste be the deciding factor.

TIP #2 – YOUR DECAF COFFEE HAS BEEN THROUGH A LOT. BE NICE.

By the time it gets to your roaster, your decaffeinated beans have already been through some stress, so be gentle. All decaffeination methods involve a re-hydration stage and are then re-dried after processing.  This expansion and contraction of the coffee will affect the structure of the coffee and the way it holds moisture. This will have an impact on how the coffee develops in the roaster. While no two beans are the same, as a general rule one can expect that a decaffeinated coffee will more readily give up its moisture early in the roast which can affect how the coffee will react at first crack.

Roasting Consultant and owner of Equilibrium Master Roasters in Australia, Anne Cooper, highlights the need to understand this: “I think the biggest thing … is that most roasters aren’t aware of [these different moisture properties] and thus wouldn’t be thinking of decaf in that way. It’s important to recognize [these differences] and roast accordingly.”

Opinions on how to approach this in the roast will be varied, but many roasters share similar advice. Matt Higgins, owner and founder of Portland’s Coava Coffee Roasters recommends “being gentle upfront of the roast to not push too hard and burn off what moisture it does have, then planning your ramp to push the coffee into crack to excite what moisture it does have to still work with.”

Revelator Coffee’s Director of Coffee Operations, Cameron Heath, echoes the gentle approach, “Knowing that the process might affect the structural integrity of the bean I make sure the roast is slow and low with a gradual application of heat. We tend to prefer a low output temperature and high development for a balance of acidity and sweetness so our approach to that stage of roasting is to embrace it. The rate of rise will fall at a faster rate but making sure my gas is decreased steadily will really help my total development.”

TIP #3 – YOU’RE NOT GOING TO LOSE AS MUCH

We’re all aware that there’s a yield loss in the roasting process, and we take that into consideration when planning our roasts and costing our roasted products. Because all decaffeinated coffees go through a cleaning process before decaffeination and a portion of the coffee has already been removed, decaf coffees will have a lower yield loss at similar development levels to non-decaffeinated coffees.

While this may not be a game-changer in your purchasing decisions, it means that the Cost of Goods per lb. of roasted coffee will be slightly lower than non-decaffeinated coffees. This could allow you to spend more than you originally thought on decaffeinated coffee, since you won’t lose as much during roasting.

If you’re one that uses roast yield loss as a measure of quality control it’s important to do is target a different yield loss percentage for decaffeinated coffee than your non-decaffeinated coffee.

DECAF JUST WANTS TO BE LOVED

Most importantly, getting the most your decaf requires that you give it the same care and attention that you give to any other coffee in your roster.

Roast it. Cup it. Make adjustments. Repeat.  It’s the same recipe for success when approaching any other coffee, only the stakes are magnified. While you may have dozens of different offerings throughout the year, most roasters usually only have 3 or 4 decafs in that same time period.  This makes the effort you put into building an appropriate profile for those offerings that much more important. Your customers will thank you.

Thanks to Swiss Water Decaf for this article.