On storage of pu-erh tea

Storage conditions have a big impact on how tea changes over time. Especially when talking about old or semi-old pu-erh teas. Because the longer the storage time, the bigger it's influence on taste, and the more apparent the differences become.

Pictured in the header are three teas, all sheng pu-erh from similar years of production, which have been kept in very different types of storage.

The first one (left) is Changtai 2002 Yi Chang Hao in traditional Hong Kong storage. This is a staple name on the Hong Kong market.

In the middle is a Jia Ji grade tuocha from 2002 (Feng Qing Tea Factory) which was kept in traditional storage until 2014 when we bought it. We like this tea for its rustic complexity and the way it ages. We’ve been using it as a benchmark for our aging conditions for years.

The last one (right) is a 2004 maocha from Da Xue Shan that's been kept in dry storage all the way through. It stayed less than a year in Yunnan before making its way to the West.

As can be seen from the brews' color, their taste and aromatic profile do not resemble each other. The level of “fermentation”, or aging of the leaves, goes according to how humid and warm the environment was in which the tea is stored. In more humid conditions, pu-erh teas tend to ferment quite rapidly. That is to say that the bacterias responsible for their aging process find this type of environment quite suitable for their activities. So they thrive and eat away the leaves with very little competition to stop them. The average humidity and temperature being higher year-round in Hong Kong than in Yunnan, and higher in Yunnan than in North America, explains the difference in the demonstration.

The challenge when storing tea in high humidity to accelerate its aging process is to keep enough different bacterias competing on the leaves to produce various kinds of flavors, textures, and aromas. Teas that have been aged too fast and too aggressively tend to be very simple and narrow in taste. TRADITIONAL storage isn't the same as WET storage though. Wet storage refers to storage conditions that have been pushed beyond the natural high humidity/temperature levels of the climate to accelerate even further the aging process. It's not unlike Wo Dui ("wet piling" - the transformation process behind shou pu-erh), just not pushed to the same extremes. Traditional storage doesn't mean no actions are taken to influence ambient temperature and humidity, but it rather seeks to stabilize it and work around it instead of accelerating it. Seasonal variations and competition amongst bacterias are important because they help create or maintain complexity in the tea. The implications are many and balancing traditional aging is quite an act. Hong Kong tea dealers are very good at this, often as good as cheese makers can be at aging their cheese or distilleries at aging/blending their whiskies.

When, however, we reduce fermentation speed, complexity tends to naturally occur (or be preserved). Competing bacterias will do it for you. The drawback, of course, is it can take many decades for a slowly aging tea to reach the earthy smoothness a traditional Hong Kong storage can produce in 5-10 years. Patience is key here. Or a deep wallet if you're not to age tea yourself.

Tastewise, the traditional storage is the earthiest of all three, has the softest mouth feel and the most soothing sensations. No bitterness. The semi-dry storage is the most complex and the boldest (because of its low-grade material and transformation, mostly). There is still a lot of rusticity in the profile, although it obviously softened over time. The dryer storage is still relatively close to the tea's original profile (regarding the maocha's aromas) but has sloooowly developed an exquisite structure and mouthfeel that can't be produced by any other means. It has both charm and aggressiveness, a silky liquor with abnormally smooth tannins.