How to store your coffee to keep it fresh and as tasty as the day it was received:
Staling is caused, in order of most harmful to least harmful
- Exposure to air (Oxidization)
- Exposure to heat
- Exposure to moisture
- Exposure to light
Roasted Coffee beans are composed of approximately 800 organic chemical compounds. Many of these organic compounds create the flavor you love.
There are sugars, alcohols, acids, Ketones, Aldehydes, minerals and all sorts of volatile flavonoids and antioxidants. When these organic compounds are exposed to air, many of them will combine with the Oxygen, forming new organic compounds that don’t taste good. The coffee becomes flat, losing its brightness and personality. This doesn’t happen immediately– it begins when you open a vacuum packed bag and the process continues on for about a month. The great flavor of high-quality coffee lasts longer at first but their fall over the cliff is more dramatic then lesser coffees. This is because the taste of lesser coffees when fresh often resembles stale coffee.
The Oxidization process is clearly observed as a freshly cut apple browns over time
- Don’t open the vacuum bag until you are ready to use its contents.
- Close the bag and within the first three days, transfer the coffee into an airtight container. No need to purchase an expensive kitchen accessory. Just use a quart mason jar and seal it with a lid.
All chemical reactions are speeded up by heat, so we want to keep the coffee at a low temperature. That will go a long way in saving the flavor.
Oxidation can be slowed down or speeded up. Temperature is the factor and since Staling is caused, essentially, by oxygen combining with other compounds, we want to keep the beans cool but not frozen.
- Store your sealed container in a cool dark pantry or in the refrigerator. If you have ordered a five-pound bag, you will need five quart-sized jars and lids.
- Cool is better than room temperature. Since warm air rises, store your sealed containers on your lowest shelves.
Your coffee beans are pretty devoid of moisture. When we put green raw beans into the roaster they are about 11% moisture. When they exit the roaster after being at high heat (400-465 degrees) they are really dry. But like a dry sponge, they will attract moisture from the air. This is Osmosis. Moisture softens the beans and further enables organic compounds to combine and change, reducing flavor and speeding up the oxidization process.
- Do not store the beans in the original vacuum packed bag for more than a few days unless you have a heat sealer. Moisture creeps into the bag easily, and even more when it is in the freezer or refrigerator.
- A sealed container is the answer to moisture.
It takes an awful lot of light to make coffee stale; if you address the air, heat, and moisture issues, then the light will become a small factor. On it’s own, in my experience, light alone will take a long long time to damage coffee beans. However, if coffee beans are exposed to prolonged sunlight, then heat becomes the primary culprit.
If you address the problems of Air, Heat, and Moisture correctly, then Light will have little effect on your coffee.