Temperature and Humidity for Pu'er Storage: Getting the Numbers Right
Everyone has heard that "pu'er should be kept somewhere dry," but how dry is dry? How cool should it be? In fact, local standards in Yunnan, tea associations, and researchers have all put forward specific numbers. Set those numbers next to Taiwan's climate and you'll know what to do at home.
What Standards and Associations Say
- National standard: China's national standard for pu'er requires storage in a clean, well-ventilated, dark, dry environment free of odors, without specifying exact temperature or humidity.
- Pu'er City local standard (Technical Specification for Pu'er Tea Storage, issued in 2020; repealed in August 2026, though its numbers are still useful as a reference): storeroom temperature should be below 25°C and relative humidity below 70%; above that, lower the temperature or dehumidify. Tea should be raised at least 10 cm off the floor, kept away from walls, and temperature and humidity should be checked monthly.
- Xishuangbanna Prefecture local standard (Technical Specification for Pu'er Tea Warehousing, issued in 2022): keep temperature at ambient levels and relative humidity no higher than 70%, dehumidifying when it goes over; tea should be raised off the floor, kept away from walls, and conditions recorded regularly.
- China Tea Marketing Association recommendation: storage temperature of about 20–25°C, relative humidity of about 55%–75%, well-ventilated, dark, and free of odors.
These numbers have one thing in common: relative humidity of around 70% is an important line.
Where Taiwan's Climate Falls
According to Central Weather Administration data, the Taipei station's average annual relative humidity over the past ten years has been about 71%–78%, with an average annual temperature of about 24°C. The Hong Kong Observatory's 1991–2020 climate normals show an average annual relative humidity of about 78%, and March to May is often 82%–83%.
In other words, if you do nothing about it, indoor humidity in Taiwan often sits at the edge of the recommended line or above it, especially during the spring plum rains and around summer typhoons. That's why, when storing pu'er in Taiwan, keeping moisture out matters more than anything.
What Happens When Humidity Is Too High or Too Low
- Consistently above 75%–80%: The leaves absorb moisture and change faster, but they easily develop a storage taste or mustiness, and in serious cases mold spots.
- Consistently below 50%: The leaves get too dry, change very slowly, and the aroma may turn flat.
- Temperature swinging up and down: Alternating warm and cold easily causes condensation inside the packaging, which is more trouble than steady high heat.
Researchers have also compared the same batch of raw tea stored in Guangdong and in Xinjiang. In hot, humid Guangdong storage the tea changed quickly and its aroma compounds shifted dramatically; in dry, cold Xinjiang storage it changed slowly and gradually, and overall quality ratings did not simply improve the faster the tea changed. That's a reminder that a stable, moderate environment matters more than chasing rapid change.
What to Do at Home
- Get a thermo-hygrometer: Put it in the cabinet or box where you keep your tea. It's far more accurate than going by feel.
- Target range: Keep temperature steady between 20 and 28°C, with relative humidity around 55%–70%.
- When humidity runs high: Keep tea in a room with a dehumidifier running, or put replaceable moisture-absorbing packets in the cabinet; avoid keeping tea on the ground floor, next to a bathroom, against an exterior wall, or near an air-conditioning vent.
- When humidity runs low: Usually no need to add humidity; just don't put tea directly in front of a dehumidifier or next to a heater.
- Raise it up and keep it off the wall: Don't set boxes directly on the floor, and leave a little space from the wall so air can circulate.
- Check once a month: Turn the tea over, give it a sniff, and note the temperature and humidity while you're at it.
Key Times of the Year
| Period | Conditions in Taiwan | What to do |
|---|---|---|
| February–May | Spring rain and plum rains, high humidity | Dehumidify, check often |
| June–September | High heat, damp around typhoons | Avoid west-facing afternoon sun and AC vents |
| October–January | Relatively dry | Open boxes to air out, tidy your tea storeroom |
Small Portions and Everyday Tea
Small-portion teas such as dragon pearls, tea bags, and loose-leaf tea are best finished within a month or two. Keep them sealed in their original packaging; there's no need to deliberately store them long-term. Only whole cakes and whole stacks that you want to watch change over time call for the effort of setting up a small "home tea storeroom." For basic storage principles, read How to Store Pu'er at Home; the concepts of dry and wet storage are in Dry Storage and Wet Storage.
Each of Guyuntang's Bingdao Old Village Dragon Pearls is individually wrapped. After taking what you need, seal the bag and keep it in a cool, dry place.
Setting Up a Small Tea Storeroom at Home
- Containers: Corrugated cardboard boxes or wooden cabinets both work; they breathe and block light.
- Location: An interior room is best; avoid bathrooms, kitchens, exterior walls, and windows.
- Tools: A thermo-hygrometer and a few replaceable moisture-absorbing packets.
- Zones: Keep raw and ripe tea apart, and loose-leaf tea apart from whole cakes.
- Records: Once a month, note the temperature, humidity, and how the tea smells.
Reading Your Thermo-Hygrometer
| Reading | What it means |
|---|---|
| Humidity 55%–70%, steady temperature | Ideal; just maintain it |
| Humidity 70%–75% | On the high side; run the dehumidifier or replace the moisture packets |
| Humidity above 75% for several days | Needs attention; check whether the tea smells damp |
| Humidity below 50% | On the dry side; just keep it away from the dehumidifier outlet |
Where to Put the Hygrometer
Put the thermo-hygrometer inside the tea box or tea cabinet, not in the middle of the room; humidity in the room and inside the cabinet can differ by several percentage points. If you store tea in several places, put one in each for more accurate readings.
FAQ
What temperature and humidity should pu'er be kept at? Based on Yunnan's local standards and the tea association's recommendation, about 20–25°C and about 55%–70% relative humidity is a good target. Most important of all is stability.
Do I need to run a dehumidifier to store tea in Taiwan? Indoor humidity in Taiwan is often above 70%, especially in spring and summer. Dehumidifying the space where you keep tea, or putting moisture-absorbing packets in the cabinet, gives you more peace of mind.
Can I keep it in the refrigerator? Not recommended. Refrigerators are humid and full of mixed odors, and the big temperature difference when you take the tea out easily causes condensation. Pu'er does best in a stable, dry, room-temperature environment.