One of the questions we get asked all the time at markets is “When was it roasted?”. Our answer is almost always “within the last week”. Sometimes folks will turn their nose up at this answer; they’re looking for the freshest possible coffee, roasted yesterday or this morning.
While we’re not ones to yuck someone else’s yum, we do have some pretty strong opinions about coffee’s freshness. (Big surprise, we know). This is because of the way coffee offgasses. For those of you looking to be the best home barista you can be, understanding offgassing is an easy step to getting just 1% better at your coffee game.
What is offgassing?
Offgassing, sometimes called degassing, is part of the coffee natural process after roasting. The same process that turns roasted coffee brown (the maillard effect) also makes the coffee produce carbon dioxide. Most of the CO2 stuck inside the beans releases in the first 24 hours, and then the rest slowly releases over several days. As the coffee offgasses, the carbon dioxide and other aromatic compounds seep out. After a couple weeks, when the coffee has completely offgassed, the beans will start to get stale, loosing their flavor and aroma.
Why does offgassing matter?
Offgassing affects how the coffee tastes and smells. When coffee is first roasted, it will have a great flavor and aroma to it, but that flavor has not really settled yet. In fact, the coffee may be a bit more sour when fresh out of the roaster. Once the majority of the CO2 is released, the coffee’s flavor stabilizes and stays more consistent for a week or two before it starts to get stale. So while you might like your coffee fresh from the roaster, it won’t taste the same a day or two later. We prefer to try coffees about 3 days after roasting because we think it gives a clearer, consistent idea of what the coffee tastes like.
This is an easy experiment you can try at home! If you do get your hands on coffee that was roasted this morning, try it. And then keep trying it over the next few days. Take some notes and observe how the smell, taste, and texture shift over that time. You’ll notice when the coffee’s flavor gets more consistent.
Coffee will offgas no matter what; it’s just what happens as part of the roasting process. And while the flavor while shift over the first few days, it will stay consistently delicious for a week or two. Looking to keep that coffee fresh? Stay tuned! That will be the subject of our next post.