We often receive questions about how to store coffee.
You often see advice that you must store coffee in a vacuum canister, but our conclusion is that storing at room temperature is fine.
It’s true that after about six months it starts to taste oxidized, so as long as you prevent oxidation you’re OK.
The two things to watch are dark-roast beans, which oxidize more easily, and the hot summer season.
So in this article I’ll explain what to watch for when storing coffee and recommend storage methods!
Enjoy your coffee all the way to the last cup while minimizing degradation of the beans.
Three factors that make coffee taste bad
What makes coffee taste bad are the three elements that oxidize coffee: light, oxygen, and high temperature and humidity.
Direct sunlight strips the aroma and increases bitterness.
Exposure to oxygen in the air reduces sweetness and acidity and produces an oxidized odor.
Higher temperatures accelerate oxidation, and high humidity lets moisture touch the coffee, causing off-flavors.
So reducing these three factors as much as possible is the key to keeping coffee tasting good!
Recommended coffee storage methods
Now let’s explain specifically how to prevent coffee from oxidizing.
Recommendations vary depending on how long it will take you to finish the coffee, so check the options to match your needs.
Store in the original bag at room temperature (within 1 month)
First, if you will finish the beans within about a month of opening, storing them in the bag at room temperature is perfectly fine.
This is because the bags used by coffee roasters are often made of materials with good light-blocking and moisture-proof properties.
For example at Waikiki Coffee, we use aluminum metallized bags that block light and air, which maintain freshness well.
They are certainly better than canisters, ziplock bags, or Tupperware at least!
Many bags have valves that let air out but not in, or are nitrogen-flushed to remove oxygen, so as long as you don’t open them, room temperature storage is fine.
If you can finish within a month after opening, simply clipping the bag to minimize air exposure is enough (no need to vacuum).
Put the coffee bag inside an aluminum can and refrigerate (within 2 months)
A method better than room-temperature storage is to put the coffee bag inside an aluminum can and refrigerate it!
The trick is using an aluminum can, which prevents flavor degradation from condensation and stops odors from other foods transferring.
With this method, the rate of oxidation is less than half compared to room-temperature storage.
As a result, you can keep aroma, sweetness, and clarity for about two months.
However, besides condensation and odor transfer, frequent in-and-out increases temperature changes that promote moisture and oxidation.
Depending on storage conditions, disadvantages may outweigh benefits, so take care.
Divide into small bags and freeze (over 2 months)
If it will take a long time to finish, freezing is the best storage method!
Coffee begins to oxidize about 2–3 weeks after opening.
If it will take more than two months to finish, freezing is recommended.
Freezing essentially stops oxidation, so it’s safe to consider that the beans won’t deteriorate.
However, you can only preserve peak freshness if you divide into small portions, seal them tightly, and take steps to prevent condensation, so pay attention to these points.
By the way, you can grind frozen coffee beans while still frozen with no problem!