How long do coffee beans stay fresh?

Whole coffee beans taste their best for about three weeks after roasting, and they stay good for a while after that if you keep them well. Ground coffee fades far faster. The Specialty Coffee Association says ground coffee might be considered fresh for about an hour after grinding, which is why we sell whole bean only and ask people to grind just before they brew.

Our own rule, from our FAQ, is to drink a bag within a month of it arriving. Here is where that number comes from, what stale coffee looks and tastes like, and what actually slows it down.

What the sources say

Peter Giuliano, who writes about coffee science for the SCA, puts it plainly: whole bean coffee can reasonably be considered fresh within about three weeks of roasting. He adds that the beans lose carbon dioxide quickly for the first 20 days and much more slowly after that.

The National Coffee Association's storage guide gives whole beans kept at room temperature one to three weeks, and ground coffee one to two weeks.

On whole beans the two roughly agree. On ground coffee they disagree by a wide margin: an hour against two weeks. We side with the SCA, because it matches what we taste. Coffee ground last week still makes a drinkable cup. It just tastes of much less than the coffee the farmer picked.

Our month runs a little past the SCA's three weeks, and we know it. Your bag reaches you some days after roasting, and flavor fades slowly rather than falling off a cliff. A bag folded shut in a cool cupboard still brews a lovely cup in its fourth week. After that the bright top notes thin out first, and each cup tastes a little flatter than the last.

Why coffee goes stale

Roasting fills each bean with gas, mostly carbon dioxide, along with hundreds of aroma compounds and some oil. From the moment it cools, two things work against you.

1. The gas leaves and carries aroma with it. The SCA's Coffee Freshness Handbook, written by scientists at the Zurich University of Applied Sciences, names this loss of volatile aroma compounds as one of the two main causes of staling.
2. Air moves in. Giuliano describes oxygen rushing in to take the place of the escaping carbon dioxide, and the coffee starting to develop off flavors. Those new compounds are the second cause, and they are what make old coffee taste papery and dull.

Warmth and damp speed up both. So does sunlight.

Grinding runs the whole process in fast motion. In Giuliano's words, the carbon dioxide that whole beans lose over weeks is lost in minutes once the coffee is ground. A whole bean keeps most of its aroma locked inside a hard shell. Grinding breaks that shell into a pile of tiny pieces and opens all of their surface to the air at once.

Signs your beans are stale

• The bag smells faint when you open it. Fresh beans fill the room the moment the bag is unrolled. Stale ones smell of dust, of paper, or of very little.
• The bloom stays flat. In a pour over, fresh grounds puff up and bubble when the first hot water hits them, because carbon dioxide is escaping. Stale grounds darken and sink.
• The cup tastes hollow. Sweetness and acidity drop away first, and what stays behind is a woody bitterness.
• A dark roast smells sharp. The oils on the surface of a dark roast can turn rancid, and you will smell it before you taste it.
• Grinding finer does not help. If you have tightened the grind and the cup is still flat, the beans are the problem rather than the recipe.

Fresh does not mean hours old

Coffee straight out of the roaster is too gassy to brew well. The escaping carbon dioxide pushes water away from the grounds, and espresso in particular tastes better after a rest of some days. We explain why in why fresh roasted coffee needs a few days.

Every bag we sell is roasted to order by our roasting partner, Roastify, in Bend, Oregon, and usually ships within four business days. By the time it reaches you it has had a few days to settle, so it arrives at the start of its best weeks.

How to keep beans fresh for longer

• Buy whole bean and grind only what the next brew needs. We compare the two in whole bean vs ground coffee.
• Keep the beans in the bag they came in, folded over, somewhere cool and dark. Our guide to storing coffee beans covers the details.
• Keep them out of the fridge. It is damp, it smells of everything else in it, and cold beans gather condensation every time they meet warm kitchen air.
• Freeze only a bag you have not opened and will not open for months, and let it come up to room temperature before you open it.
• Buy what you will drink. The NCA suggests buying enough for one or two weeks at a time. A 12 oz bag makes about 14 pour overs, so one cup a day finishes it in two weeks.
• Look for a roast date. A best by date is chosen by the seller and tells you little about when the beans were roasted.