The shelf life of coffee depends on a variety of factors:
- Processing stage
- Air circulation
In general, keeping coffee in an airtight container in a cool, dry place extends its shelf life.
Green or not yet roasted coffee has the longest shelf life of any processing stage. When stored correctly, it remains fresh for six months to a year.
The ideal conditions for storing green coffee are fairly simple. It should be kept in an airtight container at around 60 percent humidity and 75 degrees Fahrenheit. Fortunately, this is close to the typical temperature and humidity level in most homes, so you can keep your green coffee in a cupboard in the kitchen.
If you live in an area with high fluctuations in humidity, keep your green coffee in a cooler. This will regulate the humidity and keep the beans at a consistent temperature.
Alternately, freeze green coffee beans in a deep freezer. Portion them into individual bags containing the amount of coffee you'll use in one roast batch, then freeze them as quickly as possible.
Roasted Whole-Bean Coffee
Once coffee has been roasted, the volatile oils responsible for flavor and aroma rise to the surface of the beans. This transformation makes it possible to brew a flavorful cup of coffee, but it also means that the beans become stale more quickly. When stored properly, roasted beans last for up to 2 weeks.
The best way to store roasted coffee beans is in an airtight container in a dark cupboard. The bag the coffee came in may be a good choice if it is resealable and features a one-way valve. This valve allows the coffee to release carbon dioxide without letting oxygen in. If the coffee came in a paper bag, move it to a sealed jar or other container for storage.
Ideally, you should grind coffee just before brewing, and only grind what you need for a single pot. However, if you buy pre-ground coffee, the same storage tips apply. Kept the coffee away from heat, light and moisture; ground coffee stays fresh for about a week before it begins to lose its flavor.
If you see mold on your coffee beans, the container is contaminated. Throw it out and open a fresh bag of coffee.
To extend the freshness of coffee for long-term storage, vacuum seal it then store it in the freezer. When you're ready to use it, remove the coffee from the freezer and thaw it inside the vacuum-sealed bag.