DECAF
We often say around Deeper Roots that decaf drinkers are the truest form of coffee lovers: they’re not in it for the caffeine, they’re just in it for the love of the game. We take our decaf pretty seriously, but how does a plant that naturally produces caffeine become decaffeinated? There are two main methods you’ll see us roasting - let’s take a look at them.
Before we do that though, let’s talk about caffeine itself. What is caffeine? Caffeine is a convergent evolution in around 60 plants. That means that it evolved pretty much independently in plants as diverse as coffee, tea, cocoa, and even some flowers. Caffeine originally evolved as a pest deterrent. If you, as a plant, simply kill the pests that attack you evolution will self-select for those individuals that are resistant. Instead, caffeine evolved to confuse and in the case of some flowers, attract insects. In what amounts to a happy accident of evolution, this molecule blocks receptors in our brain for adenosine, a chemical that produces sleepiness - hence that jolt of energy we’re all familiar with.
To decaffeinate coffee, raw coffee beans are put through one of two processes: ethyl acetate (sometimes called sugar cane processing) and mountain water processing. Though these two processes differ, they start out the same way. Raw coffee beans are brought to a decaffeination facility and washed to remove dust or any foreign objects. Next they are polished to remove the silver skin layer and steamed. The act of steaming coffee beans helps them to open up on a cellular level, so that they are more receptive to having caffeine removed.
Here is where the two processes differ: you next add a solvent to the raw coffee to remove the caffeine. A solvent is a substance that dissolves a solute, or a specific compound we’re trying to get at - in this cafe, caffeine and hopefully nothing else. In sugar can processing the solvent is ethyl acetate - which might sound like a scary artificial chemical, but is actually a naturally occurring ester made up of alcohol and acetic acid (vinegar). It’s found in apples and pears and is a byproduct of fermenting sugar cane into molasses. The raw coffee is added to a sealed tank along with ethyl acetate where it’s held at a specific temperature and refreshed with new ethyl acetate as many as 10 times over about 8 hours. It’s agitated constantly to help “wash” out the caffeine. We use ethyl acetate because it’s very selective; it takes out caffeine but leaves most of the other compounds that make coffee delicious. Afterwards the tanks are flushed with steam for about two and a half hours, causing the ethyl acetate to boil away. Finally the coffee is dried and cooled down before it’s packed and sent to us for roasting.
Mountain water processing is very similar to ethyl acetate, however the solvent used is a proprietary blend called green coffee extract. While we don’t know exactly what’s in this, we do know that it is made from coffee, contains most of its solubles, yet leaves a convenient gap where caffeine should be. When you add the green coffee extract to water and raw coffee and heat it up, only the caffeine will extract because everything else is balanced. After coffees processed both ways are dried, they’re tested rigorously to make sure no solvent remains, as well as making sure the caffeine has been completely removed.
That’s a lot of science but suffice to say that to decaffeinate coffee you need a solvent, and that solvent is either ethyl acetate or green coffee extract depending on the process. You won’t ever see us use something called methyl chloride, an erstwhile solvent used to decaffeinate. It’s been found to be harmful even in small quantities, so we stay away from it. Regardless of the process, we roast to perfection and make sure you can be sipping any time of day or night.