If you work in coffee, some of the of the most common questions you’ll be asked are about how to store coffee. How long does it last? Should I put it in the fridge? Can I freeze it? How should I store it? As with most subjects related to coffee, there are many different schools of thought around the issue, so we thought we’d try and explain what affects coffee when it’s stored, and hopefully answer any questions in the process.
How long will my coffee last?
This is probably the most common question and the answer has many variables. The most obvious one being if the coffee has been ground or not. There is no convenient “best before” date on a bag of coffee, and it doesn’t really go off like other perishables. It is much preferable to keep your coffee as beans, ideally in an airtight container in a cool dark cupboard, and then grind enough for a single cup when you need it.
As beans, the optimal time to be drinking is about 4-7 days after the roast date, then after about two weeks the taste will flatten a little, but will by no means be bad or go off. I’ve drunk coffee that has tasted fine over a month after roasting. If the coffee has been ground, that is a different question altogether, and leads nicely on to the next question.
Should I put my coffee in the fridge? Can I freeze it?
You’ll have probably been told to never put your ground coffee in the fridge, and that is correct to a certain extent. The reason you shouldn’t keep your coffee in the fridge is because ground coffee is hygroscopic, which is just a fancy way to say that coffee absorbs moisture from the air.
It’s what means coffee can dissolve into water and become a drink, and also means that almost as soon as you grind your coffee it begins to lose its flavour. If left out in the open, ground coffee will oxidise and go stale. If you put it in the fridge, the coffee will absorb all the moisture it can and start to go bad.
Hygroscopic substances absorb odors and, when it comes to coffee, that affects the taste. If you have a bag of coffee in your fridge as well as an onion, for example, your coffee would taste more and more like onion the longer it is in there. On the other hand, if your fridge smells you can put some coffee in there to neutralise the odor!
If your ground coffee is in a completely airtight container, there is no reason why you can’t store your coffee in the fridge or freezer. If you choose to do this, I’d recommend splitting up the coffee into smaller portions, as each time you take it out and open it up, you’ll expose the coffee to a large amount of moisture.
So how should I store it?
So we’ve mentioned two of the things that majorly affect coffee – moisture and oxygen. There are two more factors that are equally important – sunlight and heat. Heat is an obvious one, if you leave food or drink out at room temperature, it goes off quicker that if it’s cold. Molecules move faster the hotter they are, therefore deteriorate quicker.
Sunlight, or light in general, causes something called photodegradation. It is the same process that causes the colour of something to fade when left in sunlight. In coffee, the light causes compounds within the coffee to degrade, which affects the taste. Put simply, it makes the coffee go stale.
The science is all well and good, but you haven’t answered the question: How should I store my coffee?
Store your coffee as whole beans if you can, in an airtight, opaque container, and put it in a cool dark place. If it’s ground, you can follow the same rules. Freezing it will keep it fresher for longer, but portion it into small amounts to avoid contamination.