Dry Storage vs. Wet Storage: How Pu'er Storage Works
Take one batch of tea, store half in Kunming and half in Hong Kong or Guangdong, and open them ten years later: you might feel they're two completely different teas. That's the effect "storage" has on pu'er.
What Are Dry Storage and Wet Storage?
"Storage" refers to the environment where pu'er is kept long-term. Depending on humidity, the tea world usually divides it into:
- Dry storage: A lower-humidity, well-ventilated environment. The tea transforms more slowly and keeps more of its original character.
- Wet storage: A higher-humidity environment. The tea transforms faster, the liquor darkens quickly and the mouthfeel becomes mellow and thick, but it can easily pick up a distinctive storage odor.
In earlier years, tea merchants in Hong Kong and Guangdong would keep tea in humid warehouses to speed up aging and make it "old" faster; this is traditional wet storage. Later, as more and more people sought a clean taste, dry storage gradually became the mainstream.
Storage in Different Regions
You'll often hear these terms in the pu'er world:
- Kunming storage: Kunming in Yunnan sits at high altitude with a dry, cool climate, so tea transforms slowly and has a clean, lifted aroma.
- Guangdong storage, Hong Kong storage: A hot, humid climate, so tea transforms faster, with darker liquor and a thicker mouthfeel.
- Taiwan storage: Taiwan is also an important place for collecting pu'er. Its climate is humid, and if storage is well managed, the pace of transformation falls between the two.
These are only broad tendencies. Different warehouses and management methods within the same region can produce different results.
How to Tell Dry-Stored From Wet-Stored Tea
| Dry-Stored Tea | Wet-Stored Tea | |
|---|---|---|
| Dry leaf | Natural color with a sheen | Dark, somewhat dull color |
| Aroma | Clean, with tea aroma and aged aroma | May have a storage or earthy odor |
| Liquor color | Shifts from yellow to red with age, clear | Darkens quickly, sometimes not very bright |
| Mouthfeel | Keeps the tea's character, with clear layers | Mellow and thick, but layers may be less distinct |
Storage Odor, Aged Aroma, and Mustiness
These three terms are often confused, but they're quite different:
- Aged aroma: The aroma produced as tea transforms naturally in a good environment, often described as woody, camphor, or jujube. It's clean and pleasant.
- Storage odor: A smell picked up from the storage environment. A mild storage odor can usually be dispelled by "airing out" (leaving the tea in a dry, well-ventilated place for a while), and rinsing the leaves an extra time or two when brewing also lightens it considerably.
- Musty odor: The smell of tea that has absorbed moisture and molded. It's sharp and unpleasant, and the surface of the tea may show mold spots. Don't drink tea like this.
What Good Storage Looks Like
Careful storage today shares a few things in common:
- Temperature and humidity are kept stable, avoiding sharp swings.
- The environment is clean, free of off odors, and out of the light.
- Raw and ripe teas are kept in separate areas, and different teas are stored apart.
- Regular inspections and records.
The China Tea Marketing Association recommends storage conditions of 20–25°C and 55%–75% relative humidity, with ventilation, no light, and no off odors, which can serve as a reference.
Your Home as Your Own Tea Storeroom
An ordinary household doesn't need a professional warehouse. Just follow four principles: dry, ventilated, out of the light, and free of off odors, and the tea you have will transform well. For practical methods, see How to Store Pu'er at Home.
Airing Out: Letting Tea Breathe
Tea bought from a more humid environment, or tea that smells of storage, can be "aired out":
- Remove the outer packaging, keeping the cotton-paper wrapper.
- Place it somewhere dry, well-ventilated, and free of off odors, out of direct sunlight.
- Leave it for a few weeks to a few months, smelling it now and then.
- Once the storage odor has faded and the aroma smells clean, it's about done.
Longer isn't always better when airing out tea; the main goal is to let the tea settle into its new environment.
When Buying Tea With Some Age
- Look at it: The dry leaf should have a natural color and sheen, with no frost-like white mold spots.
- Smell the dry leaf: A clean aged aroma is good; avoid a sharp musty smell.
- Check the liquor color: Clear and bright, not cloudy.
- Check the spent leaves: Soft and springy. Black, hard spent leaves may mean the tea was stored too damp.
The Humidity Line
Local standards in Yunnan all happen to set 70% relative humidity as the upper limit for pu'er storage: Pu'er City's 2020 technical specification for storage recommends a warehouse temperature below 25°C and relative humidity below 70%, and Xishuangbanna Prefecture's 2022 technical specification for warehousing also requires relative humidity of no more than 70%, with dehumidification if it goes higher. The China Tea Marketing Association recommends a temperature of about 20–25°C and relative humidity of about 55%–75%.
Compare that with climate data: the Hong Kong Observatory's average annual relative humidity for 1991–2020 is about 78%, rising to 82%–83% from March to May, while Taipei's average annual relative humidity over the past decade has been about 71%–78%. That explains why Hong Kong storage without deliberate control transforms quickly with a heavy storage odor, and why tea lovers in Taiwan pay particular attention to dehumidifying. The full set of figures is in Temperature and Humidity for Pu'er Storage.
What Research Says About the Two Environments
Researchers stored the same batch of raw tea in hot, humid Guangdong and in dry, cold Xinjiang and compared the changes after several years: the Guangdong-stored tea transformed quickly, with dramatic changes in its aroma compounds, while the Xinjiang-stored tea changed slowly. In the overall evaluation, faster transformation didn't mean better quality. This matches tea drinkers' experience: good storage aims for stability and cleanliness, not speed.
The Story of Hong Kong and Taiwan Storage
In the 1990s, many aged pu'er teas made their way from Hong Kong warehouses to Taiwan, which gave rise to the industry saying "stored in Hong Kong, aired out in Taiwan": tea that had transformed for years in Hong Kong's hot, humid environment was kept in drier conditions after arriving in Taiwan, and its storage odor gradually faded. This history is covered in Pu'er and Taiwan.
FAQ
Is Taiwan a good place to store pu'er? Taiwan's climate is warm and humid. As long as you control humidity and avoid off odors, it's very well suited to letting pu'er transform slowly. Taiwan is also where many aged pu'er teas are collected.
Is dry-stored tea always better than wet-stored tea? They're different styles. Most people today prefer clean, dry-stored tea, but some tea lovers appreciate the mellow, thick mouthfeel of traditional storage. What matters is that the tea is clean and free of mustiness.
Is a home in Taiwan dry storage or wet storage? Indoor humidity in Taiwan is often around 70%, which leans damp without dehumidification. With proper dehumidifying and ventilation, it comes close to dry storage conditions.