Coffee and tea are among the most expensive things per gram in most kitchens and among the worst stored. Both lose their character quickly, and most of that loss is avoidable.
What Coffee Loses
Roasted coffee contains volatile aromatic compounds that begin escaping immediately. It also contains oils that oxidise. Both processes are accelerated by air, heat, light and moisture.
The practical result is that coffee is at its best within a few weeks of roasting and noticeably flat after a couple of months. Ground coffee degrades far faster than whole beans, because grinding multiplies the surface area exposed to air.
Where to Keep It
- An airtight, opaque container at stable room temperature
- Away from the hob, the kettle and any source of heat or steam
- Out of direct light, which degrades the oils
- Whole beans rather than ground, wherever possible
- Smaller quantities bought more often, rather than a large bag used slowly
Airtight containers with a genuine gasket seal, of the kind catalogued at https://oggi.us.com/, address the air component, which is the largest single factor after time itself.
The Refrigerator Question
The refrigerator is a poor place for coffee. It is humid, coffee absorbs odours readily, and every time the container comes out condensation forms on the cold beans.
Freezing is more defensible for long-term storage of a large quantity, provided the coffee is in a genuinely airtight container and is removed in portions rather than repeatedly thawed and refrozen. For coffee that will be used within a month, room temperature in a sealed container is better.
Tea
Tea is less oily than coffee and keeps longer, but it is unusually absorbent of surrounding smells. Tea stored near spices, coffee or anything strongly scented picks up those aromas within weeks.
The requirements are the same: airtight, opaque, cool and away from anything fragrant. Green tea deteriorates faster than black and is worth buying in smaller quantities.
Tea also should not be refrigerated, for the same absorption reason.
Original Packaging
Good coffee frequently arrives in bags with a one-way degassing valve, which lets carbon dioxide out while keeping oxygen from getting in. That packaging is genuinely well designed for the purpose.
Where the bag reseals properly, keeping the coffee in it inside a container is a reasonable approach. Where it does not, decanting into an airtight container is better than folding the top over.
Buy Less, More Often
The single most effective change is quantity rather than storage. Coffee bought in a quantity you will finish in three or four weeks stays good regardless of container; a large bag used over three months does not, whatever it is stored in.
Roast dates on the bag, rather than best-before dates, are the useful indicator. A roaster confident enough to print the roast date is telling you something.
