Why does coffee need to be rested after roasting?

Super fresh – one to five day old freshly roasted coffee can sometimes be less flavoursome than when fully rested.

This is because during the roasting process of turning beans from green to brown there is a chemical reaction which produces other gases and these gasses can prevent the water and coffee from touching, therefore the coffee extraction is poor and the flavour weak.

While approximately 40% of the gases, which includes carbon dioxide, are released within 24 hours, the remaining gases will only be released slowly over the next few days.

The perfect amount of time for freshly roasted coffee to degas also depends on how it was roasted, grown, processed, and how it will be brewed but resting three to five days is therefore a good all-round practice.

So, if beans are not rested, there is a danger that trapped gas will impact the extraction – leading to inconsistent brews and sometimes sharp & acidic or even flat tasting coffee.

Even if beyond five days after roasting; when brewing you should allow the coffee to bloom to help release carbon dioxide trapped within the beans.

Blooming is wetting the grounds with a small amount of hot water. The coffee should swell & bubble. Leave it for about 30 seconds before you start making your brew by pouring in the rest of the hot water.

We hope you found this useful.