In short: Coffee beans age on contact with air and lose their aromatic compounds. Peak flavour falls roughly within the first two to three weeks after roasting, which is why the roast date on the pack matters far more than the expiry date.
Coffee as a ritual
Coffee stopped being merely a drink a long time ago. Most people would agree that a good cup is a ritual — and for coffee to give you its best qualities, it has to be fresh.
Beans age quickly on contact with air and lose their properties, which is the single fact that explains almost every disappointing bag of coffee.
What ageing actually is
Immediately after roasting the bean releases carbon dioxide and, along with it, the volatile compounds that make up the aroma. That process is fastest in the first days and continues steadily afterwards.
Nothing about the coffee becomes unsafe. It simply becomes flat, and the origin character disappears first.
Which date to read
The roast date. Expiry dates tell you about safety, not flavour: coffee is formally good for a year, but it is interesting for a few weeks.
How to store it
In an opaque airtight container at room temperature, away from the hob. The fridge is the wrong place — beans take up moisture and surrounding odours there.
Grinding
Only immediately before brewing. Ground coffee loses its aroma within minutes, because the surface area exposed to air increases enormously.
Frequently asked questions
Which date should I look for on a coffee pack
The roast date. The expiry date concerns safety, not flavour.
How should coffee be stored at home
In an opaque airtight container at room temperature, away from heat. Not in the fridge, where it takes up moisture and odours.
Should I grind in advance or before brewing
Only before brewing. Ground coffee loses its aroma within minutes.