Want to have the best coffee at home? Of course you do, that’s why you are a Cartel customer. Something I am asked a lot at the roastery is how home coffee enthusiasts should store coffee. Just to settle that question, you can’t go wrong with something airtight, light proof, and kept at room temperature. But that aside, what I really want to focus on is the question behind the question—what is freshness?
Well, simply put, it is distance from roast. Roasting is like a key that unlocks a coffee’s aromatics. It involves (among other things) the bean’s natural sugars and proteins being morphed into new magical compounds. The problem is, these aromatics are volatile and will not stick around forever. Oxygen in the air will seek them out and destroy them over time. The energy in radiated light will also affect them. But, what else have we learned about freshness?
Did you know that coffee can be too fresh for brewing? It is absolutely true. Any coffee roaster worth their salt (or sugar?) will tell you that the first twelve hours are the worst. We actually did a taste test involving the same coffee with different roast dates. The range was from one hour off roast up to well over a month. Now, every coffee will have its own sweet spot due to differences in bean density and cellular structure, but no coffee is at its best right out of the roaster. That is an undeniable fact. In our tests, the super fresh sample tasted so flat that it was hard to believe it was even the same coffee.
The culprit is carbon dioxide. It is leaving the roasted coffee at a dramatic rate immediately after roasting. This ‘out-gassing’ interferes immensely with extraction, so even though the aromatics are at their peak, they are still largely inaccessible by brewing. Out-gassing continues for several weeks but ceases to be an issue with filter coffee within two or three days (a bit longer for espresso).
Furthermore, when you see a coffee ‘bloom’ during its first interaction with water, out-gassing is what is happening at an accelerated rate. If a coffee does not bloom, it is because it has completely lost all of its carbon dioxide. The loss of carbon dioxide and the degradation of aromatics are separate events, but they happen on a similar timeline and have a relationship with each other. This is why this can be a helpful indicator.
As a rule, you can’t go wrong with brewing coffee four days to fourteen days from roast. Even if your container is not completely airtight, the aromatics are still quite potent and stable in this range. You see, the subtle outgassing at this stage acts as a natural preservative against oxidation but doesn’t interfere with extraction.
After about a month, coffee that has been stored in an airtight container or in a sealed bag with a one-way valve (hey that’s what we have!) will still be quite delicious when first opened but will lose aromatics much faster once exposed to air. It is for this reason I recommend the four/fourteen window. And with a reliable local roaster, there is no excuse!
Here is one final note regarding freshness and storage. I include this because I get asked about it a lot. Do not use your fridge or freezer. Temperature extremes will damage your beans. Room temperature is your best bet, unless you plan on deep-freezing beans for Walt Disney to enjoy when they revive him in the year 3015. This is the only reason I will condone it.