Roast date vs best before.
One of these dates tells you how the coffee will taste. The other tells you when it legally stops being food. They are not alternatives, and a bag that carries only the second is telling you something by omission.
The difference
| Roast date | Best before | |
|---|---|---|
| Answers | When was this roasted? | When does the seller stop guaranteeing it? |
| Typical span | A specific day | 6–24 months after packing |
| Useful for | Knowing how it will brew today | Stock rotation |
| Required by law | No | Usually yes |
| Tells you about flavour | Everything | Almost nothing |
A best-before eighteen months out is not a claim that coffee tastes good for eighteen months. It is a claim that it will not harm you. Roasted coffee is shelf-stable for a very long time and interesting for a few weeks, and those two facts are what the two dates are separately describing.
What the useful window actually is
Roughly three days to four weeks off roast for most coffee, varying by roast level, and it shortens sharply once the bag is open. The freshness guide covers the windows by roast level and why an open bag ages about four times faster than a sealed one.
Against that, a best-before date is not merely unhelpful — it is actively misleading, because it implies a bag six months in is fine when it is long past anything worth dialling in.
What a missing roast date means
Roasters who are proud of their turnaround print the roast date prominently. Roasters whose coffee sits in distribution for months generally do not. That correlation is strong enough to be a useful buying heuristic on its own.
It is not absolute. Some small roasters use a lot code they can decode but you cannot, and a handful of good ones print only a packed-on date. But as a rule: no roast date means you cannot know, and not knowing is itself information.
Scan the bag and Coffee Aeye pulls the roast date straight off the label, then pairs it with the date you opened it — the two numbers that actually decide how a bag is behaving today, and the pair nobody remembers a month later.
€4.29 on Google PlayDecoding the other dates you will see
- "Packed on" / "packaged on". Usually within a day or two of roasting for speciality coffee, so it is a reasonable proxy. For supermarket coffee it can be considerably later — beans are sometimes roasted in bulk and packed to order.
- "Best before" only. Work backwards. If the roaster states a shelf life somewhere on the bag or their site — commonly twelve months — subtract it to estimate the roast date. It is an estimate, not a date.
- A lot or batch code. Often encodes the roast date in a format the roaster uses internally: a Julian day number, or a compressed YYMMDD. Sometimes decodable, frequently not. Worth an email to the roaster if you buy from them regularly.
- No date at all. Rare and a genuine red flag on whole-bean speciality coffee.
Buying on the date
- Buy what you will drink in three to four weeks, not what is cheapest per kilo. A 250 g bag finished at its peak beats a kilo that spends its last month flat.
- Check the date before you pay, not after. In a café or shop this is a normal question and any speciality roaster will answer it happily.
- Online, look for roast-to-order or a stated roasting day. Roasters who roast on fixed days and ship immediately are usually explicit about it.
- Very fresh is a real consideration, not just a boast. A bag arriving two days off roast needs resting before it brews well. That is a good problem, but plan for it rather than being surprised on day one.
The one number worth writing down
Not the roast date on its own — the date you opened the bag, alongside it. Those two together are what determine how the coffee is behaving right now, and the second one is the one nobody records. A bag opened fresh and a bag opened two months late are on completely different trajectories from the moment the seal breaks, and by the time you notice the brews going flat you will not remember which one you had.
Coffee Aeye reads the roast date off the label when you scan the bag, and records the date you opened it. From those two it draws a freshness ring that accounts for both clocks — including the penalty for a bag that was already old when it was opened — so you know whether a bag is still resting, at its peak, or past the point where dialling in is worth the beans. Get it on Google Play — €4.29, one-time.