“For how long can I store coffee?” If there was a ranking of FAQs, this would be one of the top. Have a look at this blog and learn how to phrase it more accurately. The real question is: “When does coffee experience its peak flavor?”
It’s the eternal battle of beans, two forces start working against each other straight away after roasting: oxidation and carbon dioxide (CO2).
Oxidation is bad! It “attacks” the aroma of the coffee from the moment the beans leave the roaster. We could now think, we should consume it right away. But no, wait a second! The fresher the roast, the more CO2 the beans contain. Is that bad? Indeed, we don’t like CO2 in our coffee. The heat of roasting breaks the coffee sugars and amino acids into CO2. It masks the flavors, plus it affects brewing negatively, especially espresso. The extraction is too "wild" as the CO2 gas around the coffee grounds prevents the water from extracting all the good flavours from the coffee. It's almost as if the CO2 is trying to protect the coffee from getting wet.
So what do we do? We have to degas our coffee first. During the first five days after roasting, degassing is at its most aggressive rate and is losing the most CO2.
We find that our medium roasts are at their best from 1 week to 8 weeks and dark roasts from 2 weeks to 12 weeks. Filter roasts can be consumed immediately and are best up to almost 2 months.
The following graph depicts it well:
A few more interesting facts regarding “peak flavor:
- Always use coffee bags with one-way valves: CO2 can appear but flavor, aroma, acidity and sweetness retain much longer since oxygen cannot get into the bag.
- Dark roasts degasse and oxidize faster than light roasts, because the darker you roast, the more porous the beans are.
- Ground coffee increases oxidation drastically. You expose more coffee surface to oxygen.
- Very dark roasted beans have oils on the surface. The exposure of oils may cause rancid flavors.
- Yes, you can deep-freeze coffee for longer freshness. Do it in small one-way valve packages. De-freeze slowly.
- Do not put coffee in your fridge. It has no positive affect at all. The fridge environment is too moist and the coffee might absorb the taste of other products in fridge.
- Keep coffee always in a cool, dry place.
- After the peak flavor window, the coffee has less nuances, acidity, sweetness and lively level. It does not taste bad at all, but not perfect any more.
- After 90 days, the oxidation has really taken hold. The cup will taste flat, cardboard-y and stale.
- On very dark roasts, you might not taste the negative effects of oxidation (although it oxidizes faster than light roasts) because all you taste are roast flavors from opening the packaging until the last bean months later.