From the Roastery: Why do we give our coffee a rest before sending it out to you?

Coffee is part of your daily routine, but there’s a whole world behind each cup. We often get asked questions about how specialty coffee works, from roasting to brewing, and we see it as our role to share what we know.

This series of articles is our way of pulling back the curtain. We’ll talk about how coffee travels from places like Papua New Guinea, Sumatra, Brazil, and Colombia to your cup at home or in one of our outposts.

We’re starting with one of the questions we hear most: why does coffee need to rest after roasting?

What is resting (or degassing) coffee?
When coffee is roasted, the beans release gases, mostly carbon dioxide, that stay trapped inside. These gases slowly escape in the days that follow roasting. This is called degassing, or resting.

Why does it happen?
Roasting is intense. Heat triggers chemical reactions, moisture evaporates, and the beans expand. CO₂ builds up inside and continues to release after roasting. Some escape right away, but a lot lingers.

Why does resting matter?
Freshly roasted coffee smells great, but brewing it too soon often leads to a cup where the full flavour as it’s intended may not come through. That’s because CO₂ gets in the way of extraction. When hot water hits the grounds, bubbles form, stopping the water from drawing out full flavour. 

What happens when you wait?

1. Sweeter, rounder flavours - As coffee rests, CO₂ slowly escapes and volatile aromatics stabilise. This opens up deeper sweetness and origin character in the cup,

2. Easier to dial in - Less gas means your coffee bed stays stable during extraction, so it’s simpler to find the right grinder setting and shot time.

3. Less wastage - Rested coffee behaves predictably; you’ll pour fewer dud shots, use less coffee when testing, and get more consistent brews.

How long should coffee rest?
There is no one rule and a lot of it comes down to Quality Control processes, but here’s what we do at Kōkako:

• For filter brewing, coffee shines from about day 5 through day 21 and still tastes great beyond that,

• For espresso, many coffees hit their sweet spot around 10 to 28 days after roasting,

• Coffee that’s over a month old will still taste pretty good, but might be starting to lose a bit of complexity.

What happens after degassing?
Once the gases are gone, oxygen becomes the challenge. Oxygen makes beans stale over time. To protect flavour, we use packaging with one-way valves that let CO₂ out but keep oxygen and moisture away.

At home, you can help preserve flavour too. Let coffee reach it’s sweet spot, then store them well. Some people freeze their coffee or seal in a vacuum container like our Airscape storage containers: get yourself one here.

This is the first in a series where we’ll answer your most asked questions about coffee. If you’ve got one you’d like us to cover, let us know - we’re always keen to talk about coffee.