After eagerly opening the paper wrapper, I noticed some white spots spread unevenly over the surface of the tea. This elicited my first concern about its quality. Raising the cake for better inspection, my excitement was stifled by the odor of mold. This stink was immediate and conclusive proof that the tea had been tainted due to poor storage. I didn't want to disappoint my friend so quickly and kept my silence as I carefully separated the cake and prepared the tea. The liquor was dull and dark like ink. The flavor was muddy and moldy. It all confirmed my original suspicion that the tea had been contaminated.
How did this happen? The tea was stored in an overly warm and moist environment, either due to negligence or perhaps to hasten fermentation. As a result, the amount of moisture the tea absorbed rose over 10% of its total mass, creating felicitous conditions for growing mold. In China, it is not unusual to use warmth and moisture to mature puerh while it is in storage, although they are supposed to be controlled. We even have a professional term for this: "wet-stored" (shicang 湿仓) puerh. As one might suspect, the alternative is known as "dry-stored" (gancang 干仓) puerh.
Of course, it is both very disappointing and frustrating to age a cake for decades, only to grow mold, or produce what should have been a delicacy and is now only compost. So what are the significant points we should know to store our tea properly?
1. Air Circulation is necessary
Don't store puerh in a plastic bag or airtight container, because the microbes that cause fermentation need to breathe. Constant and regular air circulation will help the tea develop and blow away odors. However, puerh should not be kept anywhere breezy (e.g. next to a window, doorway, or on a balcony), as the wind will carry its aroma and flavor away. In sum, moderate air flow is important, but drafts should be avoided.
2. Constant Temperature is necessary
The best temperature to store puerh is between 68-86°F (20-30° C). If the temperature is too high, it will affect the mouthfeel. The taste could become dull, flat or sour. In addition, raw (sheng 生) puerh will sometimes develop into cooked (shu 熟) puerh (this has been reported for tea stored in Hong Kong). This means a normal indoor temperature for us would be suitable for puerh as well.
3. Moderate Humidity is necessary
As mentioned above, puerh is divided into two kinds according to storage method: "dry-stored" puerh (gancang puerh 干仓普洱) and "wet-stored" puerh (shicang puerh 湿仓普洱). The former refers to tea allowed to ferment naturally in an environment that is relatively dry, ventilated, and moderately hot; the latter refers to tea aged in an environment with low ventilation and high humidity in order to hasten development. This is done sometimes because the tea producer can make more profit on it.
If the environment is too dry, it will slow down the ageing process. So if conditions where you live and keep your tea are dry (e.g. maybe you live in a desert or alpine environment), you can put a glass of water next to your puerh, to increase the nearby humidity slightly. Alternately, if conditions are too humid, it will typically result in mold, as happened to the tea I tried at my friend's house.
4. Avoid any odor
Tea is very good at absorbing any kind of odor. Not long ago, I bought a second-hand dress that had a strong unpleasant smell. I didn't want the stench to spread to the rest of my clothes, so I left some loose tea leaves in the dresser drawer. A few days later, the tea had the strong smell of the dress, which itself smelled better than before. My advice is that you should never store your tea, no matter what kind, in an environment that has any other scents whatsoever.
5. Material to wrap the tea
Imagine tea has a life like us and needs to breathe. Pack your tea in something made from a permeable material, such as organic nonwoven bags, kraft paper bags, paper towels, wooden or cardboard boxes, bamboo baskets or husks, clay or porcelain containers, and so on. I strongly recommend you do not put puerh tea in a plastic bag if you are planning to store your tea for years. Moreover, do not keep tea in a metal container. Remember that whatever packaging you choose should have no other smell.
Once you understand puerh as having a life just like us, it becomes easier to see how to keep it alive. It should have a comfortable place to stay; somewhere not too fancy or complicated. There is no need for refrigeration (remember I am talking about puerh, not green tea), no need to seal it in an airtight container, no special equipment and no direct sunlight. You can store it in your study room where there are no other smells and some air moves through. If the room is too dry or humid, it is better to open the window once in a while. In Pacific Northwest weather or during a monsoon, the tea has a greater chance of growing moldy, so remember to examine it occasionally. Finally, I want to remind you yet again that you should never keep your tea in an area with other smells, such as a bathroom, kitchen, new cabinet, drawer holding soap, incense, etc. Moreover, you should understand that puerh cakes from the same production line will have different aromas and tastes because they have been aged in different conditions. Decades after they are made, one from Yunnan will never be the same as one from Hong Kong, Taiwan or the USA.
One final aside is that you should not store cooked and raw puerh together.
I am sure if you follow these rules to store your puerh tea, the tea will be safe and develop well. Enjoy it, and don't forget to invite me by for a sip! :)
