The debate over coffee storage rages on, with well meaning folks maintaining that the freezer or refrigerator is the optimum place for beans. Wrong. So wrong.
Lets assume that the coffee you are storing is fresh and from a credible roaster, like this one. A good way to tell is that you have bought from a café or speciality roaster: the coffee has a roasting use by date, and is packed in a bag with a valve to release the C02.
Straight up, there is your storage vehicle, a purpose built coffee bag, made to keep your browns snug. Lets also assume that you are buying coffee regularly, like through a subscription for instance. This will likely mean that you know your average usage and won’t be storing coffee for a long time. Coffee has a shelf life, and a best before. There are some tolerances in the range linked to bean and roast, but generally shelf like for freshly roasted coffee is about three weeks.
There are three main elements that speed up coffee getting stale.
- Air: Coffee oxidizes, so the more it is exposed to air and oxygen, the more the coffee flavour is degraded. The coffee bean has numerous volatile aromatics and oils which, when in contact with air become rancid and evaporate. Always aim to keep your coffee beans or ground coffee in as airtight environment as possible. While the one-way valve bag works for a small quantity used fast, if you are ordering say 500g you may need to decant. A clip lock or airtight bag or container is best.
- Moisture: Coffee is hygroscopic. It absorbs moisture from the air, which means if you live in a wet humid climate, you will have a different response from your coffee than someone in a dry cold one (grinder adjustment is all part of working through the changing elements to get best particle size).The message here is that coffee definitely doesn’t go in a freezer, or in a fridge. Ever. Period. Its needs a dry, airtight environment to keep the volatile oils fresh, and moisture and other smells at bay.
Heat: heat degrades the volatile oils in coffee. Specialty roasters spend a lot of time making sure the roasting process teases out the best flavours and doesn’t end with the bean black and oily like some of our imported supermarket Italian coffees. Likewise, you need to make sure that your machine is brewing and extracting at the optimum temperature. Storage is best at around 16-18 deg. C.
Again, airtight and dry are the mantras. Dark is also good – you may have noticed many grinder hoppers are tinted, this is to stop UV light degrading your beans. So add dark to airtight and dry and you are close to perfect. Perfection obviously being buy frequently and fresh, so storage isn’t a problem.