Why Fresh is Best
Coffee freshness isn't an exact science, as it usually comes down to the subjective nature of tastings. But science and consensus agree that two things happen as coffee ages, beginning the moment coffee leaves the roaster. Over time coffee loses aromas and begins to stale.
Especially during the first 24 hours after roasting, coffee will be degassing. Large amounts of CO2 will vacate the bean during the first day and continue throughout the first week. By day 7, coffee has reached relative stability. During this time, the aroma characteristics of the coffee will also change continually, and many people enjoy tasting these changes over the first week. Many coffees are at their peak flavor between day 2 and 5. Many people have never experienced a truly aromatic cup of coffee, as most grocery store coffees have been roasted for many weeks of not months. Grinding coffee greatly accelerates the loss of aroma and should be done immediately prior to brewing.
Coffee also goes stale as time passes. Oxygen and moisture are the two great enemies of coffee freshness. Advances in packaging have helped mitigate this problem, but not stop it altogether. Bitter compounds develop over time. The darker a roast is, the faster it goes stale, and any oils on in the coffee quickly become rancid. If you know your coffee will be around for awhile, choose a lighter roast!
Coffee freshness isn't an exact science, as it usually comes down to the subjective nature of tastings. But science and consensus agree that two things happen as coffee ages, beginning the moment coffee leaves the roaster. Over time coffee loses aromas and begins to stale.
Especially during the first 24 hours after roasting, coffee will be degassing. Large amounts of CO2 will vacate the bean during the first day and continue throughout the first week. By day 7, coffee has reached relative stability. During this time, the aroma characteristics of the coffee will also change continually, and many people enjoy tasting these changes over the first week. Many coffees are at their peak flavor between day 2 and 5. Many people have never experienced a truly aromatic cup of coffee, as most grocery store coffees have been roasted for many weeks of not months. Grinding coffee greatly accelerates the loss of aroma and should be done immediately prior to brewing.
Coffee also goes stale as time passes. Oxygen and moisture are the two great enemies of coffee freshness. Advances in packaging have helped mitigate this problem, but not stop it altogether. Bitter compounds develop over time. The darker a roast is, the faster it goes stale, and any oils on in the coffee quickly become rancid. If you know your coffee will be around for awhile, choose a lighter roast!