Most coffee bags carry a best-before date somewhere between 12 and 24 months after roasting. That date tells you when the coffee becomes genuinely undrinkable, not when it's at its best. The roast date. Which many roasters don't print at all. Is the number that actually matters.

What happens to coffee after roasting

Roasting drives CO2 into the bean. In the first few days after roasting, the coffee off-gasses rapidly. This is why freshly roasted coffee blooms dramatically when you pour hot water over it. During this off-gassing phase, the flavours are still developing and the cup can taste a bit sharp or uneven. Most specialty roasters recommend waiting 5-10 days after roast before brewing filter coffee, and 10-14 days for espresso. After that window, the coffee is at its peak for roughly 3-4 weeks before oxidation starts to flatten the flavours.

The problem with supermarket coffee

Supermarket coffee is typically roasted, packaged, shipped to a distribution centre, and then to a store. A process that can take 4-8 weeks before the bag reaches a shelf. By the time you buy it, the coffee may be 2-3 months off roast. The one-way degassing valve on the bag keeps oxygen out, but it can't stop the slow oxidation that happens from inside the bean. The result is a flat, dull cup that no amount of good brewing technique can fix. This isn't a quality issue with the roaster. It's a logistics issue with the supply chain.

What to look for when buying online

Look for the roast date, not the best-before date. If a roaster doesn't print the roast date on the bag, that's worth noting. If they do print it, check how long after roasting they typically dispatch. Some roasters batch-roast and hold stock for weeks before shipping. We print the roast date on the front of every bag and dispatch within 48 hours of roasting. If your bag arrives more than 14 days after the roast date, we'll replace it.

The roast date is the one number that tells you whether the coffee in the bag is worth brewing carefully. Everything else. The origin, the processing, the tasting notes. Only matters if the coffee is fresh enough to express it.