In an ideal world you would probably buy small amounts of green beans (perhaps from a specialist roaster), roast them yourself, and grind them immediately before you want to make coffee. However, most of us have to buy roasted beans, often in larger quantities than we can use in just a few days.
When you have to store coffee beans, remember that the main enemy is water. The volatile oils are water soluble – which gives us the flavour in the cup – but damp conditions will taint the oils. Do not store coffee in the refrigerator, because, once opened, moisture will condense on the surface of the container.
If you have to store coffee for any length of time, it is better to put it in the freezer, making sure that it is in an airtight bag. Roasted beans that are to be kept for longer than a week should always be kept in the freezer. Do not try to thaw the beans when you need them – they can go straight from the freezer into the grinder.
The other great enemy of coffee is oxygen, which oxidizes the volatile flavours. This is why it is important to grind the beans immediately before you brew. Once coffee has been ground, much more of its surface is exposed to air, which means that oils begin to evaporate and the flavour vanishes into thin air.
Do not store coffee near to other strong-smelling or strongly flavoured products. Like tea, coffee quickly picks up other scents and flavours. Store your coffee in an airtight, clean container that is reserved only for coffee.
If you buy coffee through mail order, only purchase small amounts at a time. Although you might save money through bulk buying, you will lose value as you lose flavour.
The fresher the beans, the richer and more flavourful the cup. Coffee suppliers go to great lengths, therefore, to protect the freshly roasted beans from air, heat, light, and moisture, all of which impair the flavour.
In both Europe and the United States, the packaging of coffee has become something of a problem in itself. Not only are strict national regulations about the use of recyclable materials in force in many countries, but some countries within the European Union impose even tighter limits on the kinds of material that may be used. For example, aluminum, which was once widely used, has now fallen from favor in some markets. Combine this with increased consumer awareness of the costs – both in financial and environmental terms – of unnecessary packaging, and it is easy to see why many coffee companies are investing so much time and effort into rethinking their packaging policies.
Single laminate packaging, with materials comprising many ultra-thin layers, is the mainstay of coffee nowadays, and in the United States, the traditional can has left the scene altogether – to be replaced by increasingly high-tech barrier films designed to protect the coffee. These laminated packages reduce both transport and environmental costs and some even allow consumers to reseal the bag with an enclosed zip-lock.
Most coffee packaging now uses specially designed one-way valve bags, into which the beans are packed soon after roasting. The valve on each bag allows the carbon dioxide, which is released by the freshly roasted beans, to escape, but prevents oxygen, which robs the beans of flavour, from entering. Whatever the packaging, however, remember that, once opened, coffee must be stored in an airtight container in a cool, dry place.