One of the questions that I see posted on tea forums and message boards has to do with how long tea stays fresh. Unlike most other foods and drinks in our kitchens, tea is often packaged (and/or repackaged) without a defined expiration date. There also aren't really firm rules like you might find with something more perishable. In this post, I'll do my best to address those concerns and put you on the path to tea storage success.
Types of Tea
There are six categories of tea and the way that each of them are processed effects how long the product will stay fresh. Tea with higher oxidation will generally last longer than those that are not oxidized.
- White tea is an interesting one because aging it has become all the rage recently. That being said, not all white teas are good candidates for aging. Sun-dried teas will age much like a sheng puerh. As time passes the tea will become darker and develop interesting medicinal flavors that many people enjoy. Leaves that have been dried using a heat source will not age.
- Green tea has the shortest shelf life because it is not oxidized. The leaves retain a larger portion of their enzymes, making them more susceptible to environmental damage. Most green teas are best consumed within six months to a year after harvesting. Matcha, in particular, can go off very quickly since the leaves are ground into a powder which exposes more surface area to the air.
- Yellow tea does have some oxidation due to the piling process that is repeated several times before the final drying step. I find they don't go bad quite as quickly as a green tea for that reason. In my experience, Yunnan yellow teas tend to keep much longer than their greener cousins like Meng Ding and Huo Shan Huang Ya.
- Oolong is a pretty wide-ranging category. Greener oolongs will generally not last as long as their more oxidized or more heavily roasted counterparts. Some oolongs, such as those from the Wuyi mountains, actually require resting for up to a year due to the charcoal roasting that is part of their processing. Oolong that is intended for aging is often re-roasted periodically to remove moisture from the leaves.
- Black tea is generally very shelf stable because it is nearly fully oxidized. An exception to that would be first flush Darjeeling as the leaves are still on the greener side. Black tea that is no longer good will have a cloudy, translucent appearance immediately after brewing.
- Puerh is generally considered to have the longest shelf life out of all of the types of tea. Sheng puerh can be tricky because it will not age if the leaves are exposed to too much heat during the kill-green step. This still a hotly debated subject in the tea world and I will touch on that a bit at the end of this post.
The Importance of Storage
How your tea is stored is the biggest determining factor in its shelf life. Exposure to air, heat, light, and moisture are all the enemies of tea. What that means is that tea is best kept in an opaque container with a well-sealed lid. When I worked at Teavana customers would almost always insist that they don't need a tin to store their tea in. While add-on sales are a part of any retail interaction, in this case, they actually are the best way to maintain the freshness of your purchase. Paper bags with tin ties will not protect your tea from much of anything.
Your tea is exposed to air and residual moisture each and every time you open the container in which it is kept. While this is unavoidable, it can help to keep your tea in as small of a container as possible, leaving less room for air inside. This may involve transferring as you go but it will extend the drinkable life of the leaves.
Glass jars might look pretty sitting out on your counter but both natural and artificial light will age your tea significantly faster. Heat will also rapidly steal strength and flavor from your tea. I know many people keep their tea in a cabinet over their refrigerator or stove but these areas are too hot to safely keep your tea. If it is at all possible, designate a separate area to store your tea that will keep it safe from any possible contamination.
Room temperature is the safest way to go unless you live in a place that has extreme variations in weather conditions. Some people do refrigerate their tea but condensation can be a concern as the leaves warm to room temperature. If you do opt to refrigerate your tea it is best to keep a designated minifridge for that sole purpose. Tea is very absorbent when it comes to odors and no one wants to drink a tea with hints of last night's Chinese food dinner.
Is Your Tea Still OK to Drink?
The good news is that tea very rarely actually goes bad, meaning that it won't hurt you or make you sick if you consume it. Mold is to be avoided but otherwise, tea that is past its prime will just lose aroma and strength. The best way to tell if your tea is still fresh is to rely on your senses. Smell dry leaf, brew it, and drink it! Tea should still be pleasant to drink even if it seems a shadow of its former self. Green tea won't be a delicate as it was when you first bought it but the aromas will likely still be there on some level. Metalic, mildewy, or chemical aromas are not a good sign and I would likely throw a tea that presents those smells out.
Older tea can still be very useful. I like to use them for making iced tea because the flavor is often rounder and they tend to be less sensitive to brew time and water temperature. Japanese green teas especially make for a really nice cold brew. Baking is also another great way to use up your older tea. The leaves are more brittle, making them easier to grind up into recipes.
Of course, there are always exceptions and outliers in the world of tea. I'll be sure to add to this section as new topics come up.
Home storage of puerh is a hot-button topic for many tea drinkers. It has become quite popular to build a pumidor, keep the tea in a carefully controlled and moist environment, in order to quicken the aging process. I do not store my tea in this way partly because I prefer the taste of dry stored tea but also because I would hate to lose my entire hoard to mold. For cakes that I am storing, I tend to use the cloth bags sold by vendors such as Yunnan Sourcing. It lets air in but still protects the tea to an extent.
Puerh is often billed to newbies as "the tea that gets better with age". This is not always the case though. You have to start off with quality material in order to get a good aged tea. Bad tea will still be bad no matter how long you age it. There is also the issue of production methods for sheng puerh. The leaves must not be overheated during the kill-green step. Otherwise, you'll wind up with a what amounts to a compressed green tea with a good aroma that will fall flat over time.
The trouble with flavored tea is that essential oils, dried fruits, and other ingredients are added to your tea. This can complicate things quite a bit because of the potential for introducing moisture. If the tea is not properly dried it can cause real problems for the consumer. I do find that flavored teas are unlikely to stay fresh as long as a tea that has not been mixed or blended for this reason. Teas that contain citrus fruit can actually release gases, making it difficult to open the container in which they are kept. I recommend using a tin that has an inner plastic lid rather than the kind that snaps shut in order to avoid that happening.
I'd love to know your thoughts on tea storage. What do you do with your old tea? Leave me a comment below!