Does the age of the coffee beans affect grind settings?

Coffee freshness is a dynamic process. Immediately after roasting, coffee beans contain a high volume of carbon dioxide, which is released over the first few weeks—a process known as degassing. As the beans age, they lose this gas and some of their internal moisture, which changes their physical structure. Fresh beans are dense and elastic, requiring a coarser grind to allow water to pass through at the correct rate. As beans age, they become more brittle and porous, meaning they shatter more easily during grinding and offer less resistance to water during brewing.

If you are dialing in an espresso shot, you will notice this change almost daily. A bag of coffee that was perfect on day seven might pull a shot too quickly on day fourteen if you don't adjust your grinder. To compensate for the increased porosity of older beans, you must tighten your grind—moving to a finer setting—to increase the resistance and slow down the extraction. This ensures that you are still achieving the desired contact time and flavor balance.

This phenomenon is not limited to espresso. In pour over brewing, older beans may require a finer grind to achieve the same level of extraction that you would get with a coarser grind on fresher beans. However, there is a limit to this. Once coffee beans have passed their peak freshness—typically 4 to 8 weeks after roasting—they begin to lose their volatile aromatic compounds, which are responsible for the complex flavors we associate with specialty coffee. No amount of grind adjustment can bring back the vibrant acidity or floral notes of a stale bean.

In practice, the best way to manage this is to buy coffee in smaller quantities and store it properly in an airtight container away from light and heat. If you find yourself constantly adjusting your grinder to compensate for age, it is a sign that your beans are losing their peak quality. Always prioritize fresh, high-quality beans, and use your grinder as a tool to fine-tune the extraction based on the current state of your coffee.