How do you store your coffee? We would love to hear in the comment section. But as is my custom, allow me to tell a story to illustrate why it is important to store your coffee properly.
Imagine yourself sitting at the opera house. You have paid good money to see the best in the world. The curtain is lifted and a blast of light hits the stage, almost toppling over a bleak looking figure. He proceeds to make a valiant effort, but his voice is simply weaker and flatter than anticipated, and with the finale's grand finish you are treated to this:
After the show in the lobby, you have a conversation with a stranger and you ask her, “I thought this singer was the best in the world, what do you think happened out there tonight?” She responds, “Oh he is the best, but unfortunately he ran into trouble with the authorities last night after a wild night out. Maybe it was a night in a cold and mouldy prison cell which didn't do his performance any favours.”
What does opera have to do with storing coffee?
Good coffee is brimming with art. Every quality coffee bean has locked into it the brilliant art both of creation and preparation. It can have many beautiful notes and nuances of flavour and character. In other words, drinking coffee made from such beans should be like a symphony to your senses. However, like in our story above, if you let those little brown musicians sleep in bad conditions you are going to ruin their performance.
The reason for this is that coffee is very sensitive to environmental conditions which degrade all the rich flavour substances in the coffee over time. The best coffee is fresh coffee, and good storage will slow down the staling process.
What turns an orchestra into a racket?
One study, done in the late 1980's, found about 20% of all the then known flavour substances in roasted coffee - an astounding 1600 compounds (approx.). These compounds create that symphony of flavours I mentioned above.
In fresh, well processed and roasted coffee beans, the desirable compounds are predominant. But let’s face the music - as coffee ages, processes take place that reduces the desirable compounds and increases staleness.
The four causes of senile coffee.
- 1. Dissipation: Many of the desirable flavour compounds are highly volatile and dissipates into the atmosphere.
- 2. Chemical reactions: The sensitive flavour compounds are also prone to react with atmospheric oxygen and turn into undesirable substances (oxidisation). Also, internal chemical reactions among compounds take place, degenerating the ideal composition achieved with good roasting.
- 3. Contamination: Coffee absorbs water from the environment (i.e. it is hygroscopic) and along with it any other odours or contaminants. This not only adds undesirable flavours, but the water also introduces more oxygen to the coffee, speeding up the chemical reactions mentioned above.
- 4. Temperature (and light): Increasing storage temperature, and/or exposing coffee to light, pumps energy into the coffee and thus speeds up dissipation and chemical reactions. So the logical step for many people to take is to store their coffee in the cold, dark fridge or freezer. However, what most people do not know is temperatures that are this low can change the structure of the compounds inside the coffee and actually encourage staling (see this article for more technical details ). What’s more, cooling coffee in the fridge or freezer causes condensation of water vapour on the coffee the moment it is taken out, which is contamination in overdrive.
Don’t bore me with the facts! Just tell me what to do?
Unfortunately, as with anything that ages, nothing can stop coffee from degrading over time. But with a few simple precautions, you can slow the process from hours to weeks.
- 1. Buy fresh coffee (but this can be trickier than you think): It almost goes without saying, even if you pull out all the stops - if your coffee is already stale when you bring it home, you’re fighting a losing battle. Coffee beans are optimally fresh between 7 and 30 days after roasting. Ground coffee is best right after grinding and is only passably fresh within the first week after grinding (see this excellent article for more ).
- Unfortunately, coffee you buy from a supermarket shelf most often have their best before dates months and months (sometimes a year or more) into the future, and packs can sit on the shelf for ages, as long as it is still within it's best before date. They also most often have no roasting date on the packaging. So let’s face the music - it is almost impossible to buy fresh coffee in this way, especially ground coffee.
- So if you can’t determine the roast date from the supermarket coffee, consider buying your coffee direct from a roastery. Pause Coffee Roastery always prints the roast date on every pack, and online ordering is quick, easy and secure with nationwide delivery.
- 2. Freshly grind just enough for each brew at home, if possible. (Read more about grinding here).
- 3. Use a small airtight container or packet. Common sense dictates that the container should be as airtight as possible to keep out the oxygen, damp and other contaminants. But a container with a large volume of air inside will offer little benefit, and be similar to storing it in the open since it has plenty of space for air with oxygen, damp and other contaminants inside.
- 4. Store it in a cool, dark place. But see nr 5 below.
- 5. Avoid storing coffee in fridges and freezers (as explained in the previous section). However, if you have no other option but storing coffee long term, like when you go to a deserted island or something, freezing should help to keep coffee fresher, compared to leaving it out for an extended period of time. It also helps if you are able to do nr 6 below. Just make sure you leave the coffee out to defrost and return to room temperature before opening it, to prevent condensation.
- 6. Vacuum packing can be beneficial. Vacuum sealing will minimise air and damp around the coffee and thus prevent oxidisation and contamination.
Ok, let me zip(lock) it
Now that you know the best way to store your coffee, and the science behind it, you can enjoy the symphony of flavours that your coffee was intended to play. And what a delight it is to enjoy the small pleasures in life! Life is short. Drink.Good.Coffee.