Over many years of working within the coffee industry, I have found that one question comes up time and time again. I’ll give a gold star to anyone who can guess what it is. In fact you may have askewd the wuestion yourself at some point:
How do I store my coffee beans??!…
Naturally, the answer has changed over time as industry research has exposed the effects of different practices on the freshness of stored coffee. While it isn’t a simple answer, there are certainly rules-of-thumb to follow to ensure that your coffee stays fresh, consistent and delicious.
In A Nutshell
To sum it all up in one sentence for you: Keep it away from light, heat and air… and NOT in the fridge or freezer!
In order to fully empower you to make the best decision in your circumstances, here are the latest findings on how to store coffee beans. It is important to discuss the different stages of coffee starting with raw coffee through to roasted and ground beans because another rule of thumb is this: coffee becomes less chemically stable as it is roasted and then ground. This means we need to be more diligent with our storage practices as we deal with coffee in different states if we want to preserve its flavour!
THE LOW-DOWN ON COFFEE BEAN STORAGE
We’ll start our journey with raw processed coffee also known as green coffee. The most chemically-stable the coffee beans will ever be is when the cherries have been picked, and the producer has processed then dried the coffee to a moisture content of between 8-12%.
In this stage, although the coffee still needs to be kept in a moderate range of temperature and humidity, green beans are the most resilient and have the longest “shelf-life”. Properly stored raw, green coffee can remain reasonably unchanged, in some cases, for years. Typically, green coffee is kept in either hessian or plastic sealed bags, away from sources of moisture including dew or condensation from the ground.
In summary: Green beans are most stable and can be stored for the longest time. We recommend you keep green beans away from extremes of temperature and humidity. Atmospheric air will have a minimal impact on green coffee beans.
As mentioned earlier, once we roast green coffee beans past First Crack, they undergo a significant state change which is characterised by less molecular stability. In order to understand why roasted coffee has such a reduced shelf life, we need to look at what happens during the roasting process.
This process is well researched and there are many chemical reactions that take place. Today we’ll just examine the main factors that will impact the freshness and flavour of your roasted coffee and what that means for how you should store roasted coffee beans.
The first and longest phase of the roasting process involves slowly and progressively drying out moisture content while leaving the natural oil composition. The intense heat used while roasting creates a number of by-products, one of which is carbon dioxide which is discharged from the sugars in the beans as they caramelise.
The longer we roast it, the more the oils intensify and the more gasses are created. The darker the roast profile, the shorter time you have before you start to lose flavour.
The most common roast level is espresso which is considered to be a medium to dark level of roasting (depending on who you talk to!) Therefore we’ll focus on the “rules” that apply to espresso-roasted coffee bean storage.
Freshly roasted coffee, (by our definition that means 3-5 days old) will be extremely volatile when extracting because the gasses present haven’t had a chance to “settle”. This results in obvious, big bubbles present when extracting the coffee. It will also have a fairly bitter carbonic tasting crema which will overpower the sweeter flavours present in the bean.
Therefore, it is common practice for roasteries to “rest” the roasted coffee by storing it in barrels for up to a week before packaging.
One-way valves play an important role in extending the shelf-life of the roasted coffee as it keeps the air from drying out the oils in coffee but allows the carbon dioxide to escape at a controlled rate. Once packaged in a bag with a one-way valve, roasted coffee will stay reasonably stable for about 5 weeks after the roast date.
BEST PRACTICES FOR COFFEE BEAN STORAGE
The first factor we need to control once we have opened our bag of coffee is excessive exposure to air. To manage this, a coffee container that can vacuum seal is ideal, but anything airtight will suffice.
The next thing to consider is the climate. If coffee is left in hot conditions, we will be faced with the same problem as before whereby the coffee dries out. Therefore, we want to keep it away from direct light or heat. Since hot air rises, best practice is to store coffee somewhere lower to the ground, in a cupboard would be preferable.
Finally, excessive moisture or humidity will significantly impact how your coffee ages. This brings us to another age-old question!
HOW TO STORE GROUND COFFEE
The convenience of buying your coffee pre-ground is certainly alluring however, even when stored properly you wouldn’t expect to get more than a week out of it before losing the majority of its richness and body. That being said, the same rules apply to ground coffee as do to roasted coffee. Keep it away from extremes of temperature and excessive humidity.
Since grinding coffee increases its surface area to volume ratio, relative to atmospheric air, its susceptibility to chemical change is much greater. If possible, use vacuum-sealed bags! We also recommend buying smaller portions which will be consumed within a week for maximum preservation of flavour and body.
In summary: Don’t expect ground coffee to keep its flavour for more than a week, so buy appropriate quantities. An airtight container with a vacuum pump is your best option. Keeping it away from excessive temperature conditions.
Q. BUT… CAN WE STORE IT IN THE FREEZER?!
Yes, it has been a common practice in years gone by to put your coffee beans or ground coffee in the fridge or freezer…
BUT the main problem with this is that both of these options create a lot of condensation. A fridge will take all of the moisture in the air and condense it into bigger water molecules which will settle on your beans or ground coffee and be absorbed, resulting in dulled flavour and intensity when served.
In Summary: Roasted coffee will last up to 5 weeks when stored in an airtight container with a one- way valve. It is even more susceptible to the effects of heat and moisture. Fridges and freezers will impact the quality of your coffee by increasing moisture, dulling the overall taste and mouthfeel. It is best to put your airtight container in a cool cupboard, close to ground level.