To keep tea fresh once you open its original packaging requires that you store it in an airtight non-plastic container in a dry, dark, cool environment. The ultraviolet rays in light will cause the polyphenols in tea to break down, which will reduce the tea’s aroma and taste. Do not store your tea in a refrigerator or freezer.
Matcha is the exception. Once opened, its freshness, taste, and color begin to degrade, so we advise storing opened matcha in a refrigerator in an opaque, airtight container and using it within six to eight weeks, if not sooner.
Similar to white wine consumption, green teas, white teas, and many oolongs (oxidized less than 30%) should be consumed within six to nine months after opening the original package.
Similar to red wine consumption, oolong teas (oxidized more than 30%) and black teas, should be consumed within one to two years after opening. Puerh, and some other aged teas, are the exception in that they actually age like a fine wine as they get better and better the longer they are stored. These teas need to be exposed to air, but they should still be kept away from light. Ideally, they should be stored in an environment with humidity below 50 percent and at a constant temperature of about 55-65 degrees Fahrenheit.
We recommend storing tea at room temperature out of direct sunlight in airtight opaque containers made of glazed ceramic or a non-reactive metal like stainless steel or tin. Make sure to keep your storage containers full; the more air in the container, the more likely that the tea will degrade through unintentional oxidation. It’s a good idea to keep track of how much tea you drink and buy your tea in quantities that make sense for proper storage.