In this article, I would like to talk a little about some of the most frequent questions regarding the conservation of coffee: How should I store coffee? How long does its freshness last? How do I maintain its freshness for longer? Can it be kept in the refrigerator? Can it be frozen? Etcetera.
If you ask yourself these questions, you are on the right track since many people mistakenly think you can buy a coffee in a supermarket expecting it to have months or years of shelf life.
If you are consuming coffee this way, you probably drink an oxidized or stale coffee. You may not realize it since the only thing you feel is that bitter and roasted taste with notes of ash due to the poor quality of the coffee. In addition, having such a high roast does not let you see its original characteristics.
But to answer the previous questions, we must begin by understanding a little of what happens to coffee chemically during roasting. I will explain it briefly below.
- 1 Chemical processes of coffee during the roasting process
- 2 Implications of the degassing process
- 3 What is the best way to preserve the freshness and flavors of coffee?
- 4 It is better to grind the coffee at the moment of consumption
Chemical processes of coffee during the roasting process
When roasting coffee, the beans undergo different chemical reactions and changes, such as:
- Complex carbohydrates are broken down into smaller particles.
- The beans begin to brown, and a large amount of water vapor and carbon dioxide is created. When we hear the first “crack,” which is a sound very similar to when corn explodes, it is the accumulation of the gases causing enough pressure to rupture the cell wall of the coffee bean. The development of gases continues throughout the roasting process.
- Once roasting is complete, the coffee beans release these introduced gases (most of which are carbon dioxide), in a process known as degassing.
Implications of the degassing process
It is important to remember that the presence of carbon dioxide in coffee is not bad; in fact, the degassing process plays a very important role in the quality of the coffee.
Knowing what happens during the chemical process of roasting, a question arises… do we have to consume the coffee as fresh as possible after roasting? No, it is not that simple.
Due to degassing, the carbon dioxide forms small bubbles that work as water barriers. Therefore, we will be unable to extract the coffee correctly and consistently after roasting the bean.
The result will be a coffee with a very high and sharp acidity, rough and astringent. This coffee must degas for a few days to allow the flavors to shine.
How long does the coffee need to degas?
This is the question we should ask ourselves: how many days does the coffee need to degas to be at its optimum point? It will depend on several factors, such as the extraction method, the beans’ processing, density, and the roasting level.
1. Degassing time according to the method of extraction
If you use this coffee for espresso, the resting and degassing time should be approximately two weeks after roasting or even a little more. On the other hand, if you are going to use it for filtered methods such as the French press, you can start using it one week after roasting since the extraction times are much longer than those for espresso.
2. Degassing time depending on bean processing
It will also depend on the processing of the beans; washed, natural, or honey. For example, raw beans need more time for degassing than washed ones.
3. Degassing time according to grain density
The density of the bean also has an influence. For example, coffees from greater heights are generally denser and have a more compact cellular structure, so they retain more gases and need more time to degas.
4. Degassing time according to roasting level
Another very important point is the roasting level. A dark roast accelerates degassing because the beans undergo greater degradation. While with a light roast, a greater part of the grain remains intact, so it will need more degassing time.
Is it worth buying fresh coffee, knowing you should wait for it to degas before consuming it?
Perhaps at this moment, you are wondering… if the coffee needs time to degas, why bother buying fresh coffee? The thing is that after the necessary degassing, the beans enter their optimal point of consumption, and you can feel how it evolves day by day.
From my experience, I have tasted some of the richest coffees four weeks after roasting in espresso. But since it continues to release carbon dioxide throughout this time, we can move to the other side and feel how the aromas and flavors will gradually fade and be lost.
With time, the coffee will oxidize and become rancid with unpleasant flavors, depending on all these variables I have already mentioned, after the fifth week of roasting. But all this is assuming that the beans were perfectly packaged and stored.
What is the best way to preserve the freshness and flavors of coffee?
Coffee is food that reacts with oxygen. Therefore, we must find a way to reduce this contact as much as possible. For this, you can use some methods such as the following:
Airtight coffee bags with valve
In most cases, we recommend the original bags in which some quality coffees come since they have an airtight container made of aluminum inside and a unidirectional degassing valve.
Once the carbon dioxide accumulates inside this bag, when pressed, the valve expels it outwards without allowing any air to enter. This is also why removing all the air before closing the bag after each use is very important.
Vacuum-sealed coffee containers
There are also other options, such as vacuum-sealed containers, with some system where all the air that remains inside is expelled.
In reality, not all the air is extracted, generating a vacuum. Still, they are very efficient, especially if they have an indicator that indicates when all the air has been completely expelled.
Comparing this form of packaging with airtight bags, it has been shown that during the first two weeks of storage, the differences are minimal. But after this time, vacuum-sealed containers have an advantage and maintain flavors better over time, so you may consider using them.
Should coffee be frozen to preserve it better?
If you have a coffee that you know will not use for a long time, a month or more, and you do not want it to worsen, you can consider freezing it. Many studies prove that at -40 degrees Fahrenheit the degradation of coffee is completely stopped.
However, domestic freezers reach approximately -20 degrees Fahrenheit, enough to delay coffee’s aging drastically. However, to do so, some details must be taken into account:
- The ideal would be to store the coffee beans in a vacuum bag, or at least in a bag or jar that is airtight and without leaving much space between the coffee beans. Look for a container that is the size of the amount of coffee you have.
- Once you decide to use it, it is very important to let it thaw in this container without opening it until it reaches room temperature. For example, you can take it out at night, and it will be ready to use the next morning.
- Remember to let it degass for a few days after roasting, depending on the extraction method and the variables I have already mentioned.
Knowing that freezing coffee keeps it better, the question arises as to whether it is equally useful to store it in the refrigerator. The answer is a resounding no. Coffee is like a sponge that absorbs humidity and surrounding odors.
Even if we keep it in an airtight jar, every time we take it out to use it, condensation will be created due to the temperature difference. Therefore, a lot of humidity will be very bad for this coffee.
The bag or jar where we store it should be in a dry environment, ideally with a cool temperature of around 68 degrees Fahrenheit and in a dark place outside the reach of light.
It is better to grind the coffee at the moment of consumption
Another detail to mention is that if we buy already ground coffee, everything we were talking about, the degassing will happen much faster since there is more surface of the beans in contact with oxygen. So ideally, it should be ground at the moment of consumption, provided you have a good grinder.
Considering all of the above mentioned, we guarantee that the coffee will remain as fresh as possible and thus we can enjoy it to its full potential.
Don’t miss my experience using this manual espresso machine for more than two months; The Picopresso.