Daily Life

License article

Why coffee should not be stored in the freezer, despite the advice that abounds

Australians might be regulars at our local cafes, but an awful lot of us prefer a home brew. If you're in the latter camp, the key to a perfect cup may lie in how you store your coffee.

The fridge or freezer should be avoided, coffee experts say, because the humidity and temperature changes cause condensation. Moisture is the mortal enemy of coffee beans and can rapidly turn them bad, spoiling the taste.

"The cell structure changes, which causes a loss of the oils that give coffee its aroma and flavour," Starbucks taster Scott McMartin explains.

This applies to the stash of coffee you access daily. But there is debate about whether it's OK to freeze larger reserves. According to the US National Coffee Association, you can refrigerate beans for up to a month - but only if they stay there for the whole period. Once the coffee is out, it's out for good. It is best to divide your stockpile into small, airtight portions, rather than dumping large bags in the freezer, they contend.

Others, however, have a slightly different take. California-based coffee guru Tony Konecny says there is no point freezing your coffee unless you plan on keeping it for longer than a month. "For shorter stints, you're better off just storing it airtight at room temperature," he argues.

Minimising airflow is an important part of storing your coffee properly. The beans do not respond well to sunlight, and should be kept in a cool, dark and dry place - such as a cupboard. The bag the coffee came in may be ideal, particularly if it has a one-way valve to allow carbon dioxide out without letting air in. Good old oxygen is "perhaps the biggest coffee killer of all",  says  a US-based coffee blog.

Vacuum-sealed bags, on the other hand, are problematic for fresh coffee. The seal will preserve the beans for longer but it generally means the beans have released all their gasses since roasting and have probably been sitting around for some time. According to Coffee AM, freshly-roasted beans stored in a valve-sealed bag will be at their best 48 hours after roasting.

Another pitfall can be forgetting to properly reseal your container. Some home brewers are tempted by expensive storage gadgets and gizmos but Mr Konecny says these are generally too tricky by half. "If it plugs into a wall outlet, don't store beans in it," he recommends.

Leaving your coffee in the grinder is also unwise, Mr Konecny says, because it is likely to just go stale.