Roasted coffee beans are at their best between roughly one and four weeks after roasting. Before one week, they are off-gassing too much CO2 to brew evenly. After four to six weeks, the volatile aromatic compounds have started to fade and the cup turns flat.
The freshness timeline
Days 0-3 post-roast: Too fresh for most brewing methods. The CO2 produces excessive bloom and uneven extraction.
Days 4-7: Espresso starts settling in. Pour-over still bloomy.
Days 7-21: The peak window. Coffee tastes the way the roaster intended.
Days 21-42: Still good, slowly fading. Flavor notes get less distinct.
Day 42 onward: Stale territory. The coffee is drinkable but the brightness, sweetness, and complexity are gone.
Whole bean vs. ground
Pre-ground coffee loses freshness within hours of grinding, not weeks. The increased surface area exposes the coffee to oxygen and accelerates flavor degradation. Even the best beans, if pre-ground at the roastery and shipped, will be noticeably stale by the time you open the bag.
Storage matters
Keep beans in an airtight container at room temperature, away from light, heat, and moisture. The original bag with a one-way valve is fine if it reseals well. A purpose-built bean canister with a CO2-release valve is better for serious users.
Do not refrigerate. The temperature swings every time you open the door cause condensation, which is the worst thing for coffee. The freezer can work for long-term storage if you portion beans into sealed bags and never refreeze, but for normal weekly drinking, room temperature is best.