How to store your puerh tea

I was so excited! One of my friends invited me to taste a puerh tea produced in the 1980s. The cake had just arrived from China, and in a week we would meet to share it together. This week seemed neverending. When the date we set finally arrived, I raced to his place for a taste of something genuinely special.

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. 

                                                                    "Dry stored" puerh

                                                                  "Wet-stored" puerh


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! :)

How to keep your tea fresh

Even if you buy the highest possible quality tea, if you don't store it well, you will just waste your tea and money because the tea will lose its color, aroma and taste. Why does that happen and how should we store tea properly?

First of all, please allow me to explain some important characteristics of tea.

• Tea is good at absorbing moisture.

Experiments have been conducted on dry tea leaves left unwrapped indoors. After one day, the water content of the tea was about 7%; five or six days later, it had increased to more than 15%. In another test conducted in rainy weather, the water content in tea left exposed for one hour increased by 1%. If you don't believe me, you can perform your own test: put some dry loose tea in an open space next to a container of water overnight. The next day, you will find that the tea leaves will be more damp. Moreover, when the water content of tea reaches higher than 10% (the water content of good fresh tea is around 3%-5%), the tea will become moldy and lose its value.

• Tea is good at absorbing odors.

Again, you can test this by leaving your tea next to some ground black pepper, scented soap, or other odiferous things overnight. The following day, your tea will smell like black pepper, soap or something else. When tea loses its fragrance or is polluted by other odors, the value of tea greatly decreases.

• Tea is easily oxidized (i.e. it is a fresh product that can become stale).

Tea oxidizes naturally during storage. The longer tea is stored, the more its color, fragrance and flavor will change - especially green tea. Tea will oxidize
more quickly at higher temperatures or in a moist environment.


Secondly, let's analyze the factors influencing quality during tea storage.

1. Temperature:

The quality of tea deteriorates more rapidly at higher temperatures. Tests have shown that an increase in temperature of 10℃(50℉) causes an increase of 3-5 times in the rate of discoloration of tea due to oxidation. This is because the chlorophyll in tea easily breaks down when exposed to heat and light. Refrigeration is a good way to prevent this kind of deterioration.

2. Moisture:

When the moisture of tea increases, chemical components such as polyphenols and chlorophyll will break down more rapidly. It also creates an environment more attractive to mold, which of course accelerates decomposition. To prevent this the moisture content of tea should be kept below 5%. Accordingly, if you refrigerate your tea, don't let any moisture (e.g. condensation) inside the package.

3. Oxygen:

Roughly 20% of the air we breathe is oxygen, so if tea is left unsealed, exposure to air will speed up oxidization. Store tea in a container with an airtight seal.

4. Light:

Light also speeds up the chemical reactions in tea; when exposed to sunlight, tea will develop a stale taint and deteriorate more quickly. Tea should be stored in an opaque container.

To summarize, proper storage of tea has two fundamental requirements: first, a dry place; second, a temperature no higher than 5 ℃. The key to keep your tea as fresh as possible is to seal it in an airtight bag or in a jar/container and save it in a clean, dry, cool and dark place. It is good to store tea in the refrigerator (-4℃to 2℃), but you must make certain it is not exposed to other odors inside the refrigerator - this is especially true for a high quality green tea. In addition, a large quantity of tea should be divided into small packages, which can then be vacuum sealed. Black or oolong teas stored in a sealed package at a low temperature will keep for one to two years (although very delicate green teas won't last that long - a year is about the longest they'll last).

Of course, if you drink tea every day like me, you can simply finish it all before it goes bad. :P