Degassing

The release of carbon dioxide from roasted coffee in the days and weeks after it leaves the roaster. CO₂ is trapped inside the bean during roasting and slowly escapes through the cell structure as the coffee rests.

Why it matters — Fresh, gassy coffee doesn't extract well — the CO₂ disrupts the brewing path, producing sour, sharp shots and aggressive blooming in filter brews. Letting beans rest 10–21 days after roasting typically produces more balanced, repeatable cups.

Good to know

• Espresso usually wants 10–21 days of rest; filter is often great at 14–28 days; some lighter roasts open up at 4–6 weeks.
• Don't buy bags without a roast date. Without it, you're guessing where the coffee is in its life.