If you want to drink premium coffee, the quality of the coffee ingredients and the procedures for preparing it are obviously important factors, but so is its state of preservation: what’s the best way of preserving coffee?
Let’s start by saying that there are various coffee “formats” on today’s market: ground, coffee beans, in pods and in capsules…and each format has different indications regarding preservation.
Generally speaking, coffee is sensitive to air, coldness, heat and light. This is because it is rich in fats, which during the roasting process become concentrated on the bean’s surface. When fat comes into contact with the air it turns rancid and oxidises. Humidity and heat act to accelerate this process. On top of this, the roasting process causes the coffee beans to swell, which renders them more porous and more penetrable by air and humidity compared to a freshly picked bean.
Coffee, in other words should be consumed as quickly as possible, given how quickly it deteriorates. This is illustrated by the so-called “rule of 2”, which goes “50% of coffee bean aromas deteriorate in 2 days, 50% of ground coffee aromas deteriorate in 2 hours, and of espresso in a cup 50% deteriorate in 2 minutes.”
How to preserve ground coffee
Let’s start by considering the most common type of coffee in Italian kitchens: ground coffee.
We all relish the intense aroma of coffee when we open a new pack, but what should we do to preserve this aroma for as long as possible?
Ground coffee is the most delicate of all coffee forms: compared to unground coffee beans, a much higher percentage of its surface comes into contact with atmospheric agents and so it deteriorates much more rapidly. This is why manufacturers vacuum-pack it, with light-proof packaging material.
However, once the 250 gr “brick” is opened, the coffee needs to be urgently stored out of contact with air, coldness, heat and light. This is why ground coffee should be preserved in a non-transparent hermetic container, in a cool dry place. For example, shut in a light-proof jar closed inside a cupboard, far away from heaters or direct sunlight.
Many people suggest storing coffee in the fridge, but we discourage this, for at least three reasons. First of all, the coffee would be subjected to a major thermal shock, and secondly it would come into contact with the condensation inside the fridge (seen in the drops that form on glass fridge containers). And as we have seen, coffee doesn’t like either cold or moisture. Plus, thirdly, the coffee would risk absorbing the odours of foodstuffs inside the fridge… as can be seen from the “granny cure” for eliminating unpleasant smells in a refrigerator, namely placing a jar of coffee inside.
For the same reasons, storage in a freezer is also to be avoided.
Various coffee fans have conducted “experiments” in which they tasted coffees stored in a cupboard and compared it with coffees stored in refrigerators and freezers: the cupboard-stored coffees preserved their aromas best, with taste and aroma much more intense than the other two kinds.
In general, ground coffee should be consumed over a short period (within two or three weeks of opening the pack), because product quality deteriorates every time it comes into contact with the air, i.e. every time we open the container where it’s stored. This is why it’s a good idea to buy amounts of coffee in line with your consumption rate and to open packs just before consumption.
Bartenders, however, have to always serve optimum quality coffee, and therefore ought to throw away ground coffee from the previous day, or use it first thing in the morning to start their coffee machine.
How to preserve coffee beans
Coffee beans are generally packaged in roasting plants, inside bags fitted with one-way degassing valves that allow gases to filter out from inside. This is because they are packed immediately after roasting, and so they continue to release the gases absorbed during the roasting process: without a degassing valve the pack would risk bursting. At the same time, it is vital that air passes only from inside to outside the pack and not vice versa: if air entered the bag it would risk damaging the coffee.
Once the pack is opened, coffee beans preserve much better and for much longer than ground coffee, because the amount of surface in contact with the air is less. Home-ground coffee beans will always taste fresher than packed ground coffee and have more aroma, so long as the grinding is done just before consumption, and in minimum amounts…i.e. the amount you are about to consume. The degree of grinding (finer or coarser) should be adjusted according to the amount of moisture in the air.
As with ground coffee, a coffee bean pack, once opened, should be stored in a cool dry place, protected from air, light, heat and cold.
Bartenders generally consume large amounts of coffee beans during the day, and this explains why bar coffee doesn’t have time to deteriorate and so maintains excellent quality. If some coffee beans are left unused at the end of the day, we suggest returning them inside their pack, closing it tightly, and storing it underneath the counter until the following morning. Another good practice rule is to wash the transparent bean container at least once a week, to eliminate oily residues. Then, before refilling, make sure it has totally dried.
Coffee bean blends, even if slightly less practical, are preferable to ground coffee because in this format the coffee retains more of its integrity and its sensorial pleasures. That’s why true “coffee purists” have a grinding machine in their homes: so that they can always serve freshly ground coffee, as in a bar.
How to preserve capsule coffee
Capsule coffee comes in two types: self-protecting or not self-protecting.
Self-protecting capsules have a layer of aluminium applied, which avoids oxidisation and contact with oxygen. This means that they can only be consumed by using coffee machines with needles, and cannot be used in water-pressure machines. Self-protected capsules can therefore be left in contact with the air, because they will not deteriorate: so, no problem with ornamental designer capsule bowls on display in kitchens or office meeting rooms!
In the case of non-protected capsules, however, the coffee is in direct contact with the air, and deteriorates after a while… consequently, these capsules are sold in vacuum-packed containers. Once the pack has been opened, the capsules should be stored in a closed bag and consumed relatively quickly… approximately within 2 weeks. Capsules that are not self-protecting can be used both in machines with needles and machines that function via water pressure.
How to preserve ESE coffee pods
Let’s start by explaining that ESE stands for Easy Serving Espresso, an open access system par excellence. This means that all coffee pods are compatible with all the machines that use the ESE coffee pod system… unlike capsules, which change format according to the system used (e.g. Nespresso*, A Modo Mio*, Dolce Gusto*…etc.).
An ESE coffee pod consists of filter paper wrapped around 7 gr of compacted ground coffee. It is packed in a protected atmosphere and hermetically closed, which guarantees a certain qualitative constancy: for quite a while its coffee content maintains its sensorial properties… undoubtedly for much longer than normal ground coffee. Coffee pods are often sold inside plastic mono-packaging, ensuring that the coffee preserves its fragrance for even longer. The only care to be taken is, as usual, to store them in a cool dry place and consume them before the sell-by date on the pack.
Coffee pods are highly practical to use: the dose is already prepared and you don’t get dirty in any way while preparing the coffee. They also have minimal environmental impact, being totally recyclable as wet organic waste.
To sum up…
Coffee is a highly delicate product. In contact with air it deteriorates rapidly, due to the fats present on the surface of coffee beans. As a result, the coffee contained in all kinds of format should be stored away from air, light and extreme temperatures.
The most delicate and vulnerable format is ground coffee, which loses its aroma a few hours after opening and which needs to be drunk quickly. The best way of preserving it is inside a hermetically sealed light-proof container, stored in a cool dry place.
Coffee beans maintain their sensorial properties for longer, but they should be ground at the last minute to achieve optimal quality. If any beans are left over, remove them from the container attached to the grinder and return them to their packaging bag, closing it tightly.
The preservation of capsule coffee depends on whether the capsule is self-protected (closed hermetically) or not. In the first case, the capsule can remain in contact with the air for long periods, but in the second case it should be stored in a closed lightproof bag, away from direct heat, and consumed within 2 weeks.
And, to conclude, coffee pods maintain their coffee’s sensorial properties, because the filter is hermetically closed. It is anyway important to keep an eye on the sell-by date indicated on the pack.
Now that you have learned how to best preserve the coffee in different kinds of formats, you should learn how to best carry out the next step too: how to make it. Read this article to discover the best methods (link to article on “how to make coffee”) and… enjoy your coffee!