The process by which CO₂ escapes from freshly roasted coffee. Heavy degassing in the first 24–72 hours can disrupt extraction. Most roasters recommend resting coffee 5–14 days after roasting before brewing. That one-way valve on coffee bags lets gas out without letting oxygen in.
Brewing coffee on the day of roasting produces an uneven, gassy cup. Waiting 7–10 days lets CO₂ escape and allows extraction to stabilize.