Although they are rare in the Western tea world, tea jars are common in Asia. Similar to tea caddies in certain respects, but more often than not made in a rounded, bulbous shape, tea jars are clay or porcelain vessels that are used to store teas, either for consumption on a regular basis or for aging. Tea jars are most often used for oolong teas, puerh teas and Japanese green teas, though they may also be used for other types of tea as well.
How Tea Jars are Used to Store Teas
Generally, puerh teas are stored in more porous tea jars with a loose lid (such as a loose-fitting lid of the same material as the jar, a rough-hewn wooden lid or a cork lid) or a piece of cloth draped over the mouth of the jar.
This is true for sheng puerh and shou puerh, and for puerhs that are for drinking now or for aging, because (generally speaking) moisture in the air and seasonal changes in climates like those in Hong Kong, Taiwan and Malaysia are good for puerh storage.
Oolongs that are intended to be consumed soon are usually stored in a glazed or less porous jar with a tight-fitting lid. Oolongs that are being aged are usually stored in a non-porous jar with a lid that has been sealed with wax to keep moisture out. This is because moisture level changes and high moisture are not good for oolong tea storage.
In Japan and certain other areas, green teas are also stored in jars. For example, traditionally, matcha green tea was stored in a large jar that was sealed with an elaborate knot. Each year, the matcha was aged a bit, knot was untied on a special day in the autumn, and the start of matcha season began. Today, matcha is often stored in a small jar (a tight-lidded vessel usually made of glazed porcelain and known as a cha-iri) until just before a tea ceremony, when it is sifted and transferred to a natsume (which is a bit like a jar, but with a low-slung, looser lid).
Today, many other Japanese green teas are stored in vacuum-sealed bags or in airtight tea caddies. However, some still use traditional tea jars, which allow the tea to age differently.
Types of Tea Jars
In Asia, there are many vintage and antique tea jars available. These often originated as water jars, alcohol jars or jars for pickled / fermented foods, such as kimchi or Japanese pickles. Some of them still have their original wooden lids, which have usually warped badly over time. These can be used on their own for storing puerh if they're in good enough condition, or they can use used along with a piece of cloth.
There are also many modern tea jars available in Asia. They are usually made of glazed ceramic or porcelain material, and they typically have a foil-lined lid. The foil is pleated around a stopper-like portion of the lid, so it adjusts to the shape of the neck of the jar and fits very snugly.
There are also some very beautiful, handmade clay jars which are intended for puerh storage; these usually do not come with a lid or have a cork or cloth lid.