Is the roast date or the "best by" date more important?

When you are buying coffee, the roast date is the most reliable indicator of quality. Coffee is a perishable food product, and its flavor profile changes dramatically in the weeks following the roast. Most specialty coffee is at its peak between one and four weeks after the roast date, as the beans have had time to degas—releasing carbon dioxide that can interfere with extraction—but have not yet lost their volatile aromatic compounds to oxidation.

'Best by' dates, on the other hand, are often misleading. They are frequently set by manufacturers to indicate a shelf life of six months to a year, which is far beyond the window of optimal freshness. By the time a bag of coffee reaches its 'best by' date, it has likely been stale for months. These dates are designed for inventory management and retail convenience, not for the consumer's sensory experience.

If you see a bag of coffee with only a 'best by' date and no roast date, it is a red flag. It suggests that the roaster or retailer is not prioritizing the freshness of the product. In the specialty coffee world, transparency is key; a roaster who is proud of their product will always include the date it was roasted so you can enjoy it at its best.

In practice, look for bags that clearly state the roast date. If you find a bag that was roasted within the last two to four weeks, you are in the 'sweet spot' for brewing. If the coffee is older than two months, it will likely taste flat, papery, or bitter, regardless of what the 'best by' date says. Always choose freshness over the convenience of a long shelf life.