Sun-Dried, Oven-Dried, Pan-Dried: Why Pu'er Has to Be Sun-Dried

In Yunnan's tea mountains, leaves from the same large-leaf tea tree can be made into several kinds of tea. The early steps (withering, kill-green, rolling) are much the same; the real fork in the road is the final drying. Tea dried in the sun is called "shaiqing" (sun-dried), tea dried with hot air is "hongqing" (oven-dried), and tea dried in a wok is "chaoqing" (pan-dried). Pu'er's national standard is clear on this: the raw material for pu'er is Yunnan large-leaf sun-dried tea.

Three Ways to Dry

The kill-green temperatures for the three also differ somewhat. Rule-of-thumb figures in the trade are roughly 200–300°C for chaoqing, around 260°C for hongqing, and about 200°C for shaiqing, and during sun-drying the leaves themselves usually don't get hotter than 60°C. These numbers vary with the pan, the batch size, and the tea maker's technique, so take them only as general guidance.

Why Pu'er Is Sun-Dried

Gentle Temperatures

Hongqing and chaoqing dry at high temperatures and fast, so the leaves set quickly and the aroma is bright and lifted. Shaiqing, by contrast, loses moisture slowly in the sun, and the leaves experience much lower temperatures. The tea world widely believes that this gentle drying leaves more room for later transformation, which is why sun-dried tea, once pressed into cakes, can keep changing year after year.

Moisture Standards

The Yunnan Tea Circulation Association's 2021 group standard, Sun-Dried Tea (Large-Leaf Variety), caps the moisture of sun-dried tea at 10% and explicitly excludes practices like withering for oxidation, yellowing, reddening, and leaf tossing (yaoqing) that cause early oxidation. Pu'er's national standard sets moisture limits of no more than 13% for raw tea, no more than 13% for loose ripe tea, and no more than 14% for compressed ripe tea. The sun-dried tea itself has to be dry enough so that steaming, pressing, and storage go smoothly later on.

The Underlying Character

Sun-dried tea has what tea drinkers call a "sunshine taste" or "sun-dried note": a steady, understated aroma and a thicker body, and with storage the brew gradually becomes even thicker. This underlying character is one of the biggest differences between pu'er and other green teas.

How to Tell Sun-Dried From Oven-Dried

Now and then you'll come across "pu'er-style" tea made from oven-dried leaf, or tea that blends sun-dried and oven-dried leaf. It's hard for most people to tell at a glance, but there are a few things to look for:

1. Dry leaf aroma: oven-dried tea often has a distinct beany, fresh scent that smells "brighter"; sun-dried tea's dry aroma is lower and deeper, with a hint of sun-baked character.
2. Liquor color: fresh sun-dried tea mostly brews yellow-green to golden and clear; oven-dried tea leans green with some yellow.
3. Taste: oven-dried tea has a high, fresh, brisk aroma on entry but a thinner body; sun-dried tea may not be as aromatic on entry, but it has a thicker body and a clear huigan (the sweet aftertaste) once the bitterness and astringency fade.
4. Time: oven-dried tea's aroma noticeably fades within two or three years and turns flat; sun-dried raw tea, after a few years, develops aged aroma and a mellow, rich body.

If you have a new raw tea, brew it at the same time each year and keep notes, and in three to five years you'll clearly feel the sun-dried tea "growing up."

Sun-Drying Depends on the Weather

The quality of sun-dried tea is closely tied to the weather. On sunny days with plenty of light, maocha dries in a day or two and the aroma is clean; during stretches of rain, farmers have to spread the leaves indoors or use low-heat drying to keep them from spoiling. This is one reason pu'er "depends on the vintage": from the same mountain and the same farmer, maocha flavor rises and falls between sunny and rainy years.

After Sun-Drying

Finished maocha takes one of two paths. Sorted, picked over, and then steamed and pressed directly, it becomes raw pu'er; put through wet-piling fermentation first and then sorted and pressed, it becomes ripe pu'er. For the difference between the two, read Raw and Ripe Pu'er: Two Paths From the Same Leaf; every step from fresh leaf to sun-dried maocha is covered in Sun-Dried Maocha: Where Pu'er Flavor Begins.

Guyuntang's Bingdao Old Village Dragon Pearls are raw pu'er. Brew one in a gaiwan and smell the lid for that steady, sun-dried note.

The Role of Oven-Dried and Sun-Dried Tea in Pu'er

You'll occasionally find teas that blend sun-dried and oven-dried leaf, or cakes pressed from oven-dried leaf. They aren't necessarily unpleasant, and when new their aroma can even be more appealing. But under pu'er's national standard, the raw material must be sun-dried tea, and oven-dried tea's aroma fades noticeably within a few years, so it isn't suited to long-term storage. If you plan to buy tea to age, choosing tea that's clearly labeled and made from sun-dried leaf is the safest bet.

A Small Experiment

If you can get hold of both sun-dried maocha and an oven-dried green tea:

1. Take 3 g of each and steep in 150 ml of boiling water for 2 minutes;
2. Smell the dry leaf first, then the wet leaf, then drink;
3. Let both cups cool and taste again.

The oven-dried tea usually leads with aroma and has a thinner body; the sun-dried tea has a steady aroma and a thicker body, and it stays sweet even after cooling.

How Sun-Dried Tea Ages

Both research and tea drinkers' experience show that the aroma of sun-dried raw tea changes most in the first few years of storage. Aroma compounds are at their richest around the 3rd year, and woody, aged aromas begin to appear around the 8th year. This long, steady transformation is the key reason sun-dried tea is the raw material for pu'er. Further reading: Pu'er Aging and Vintages.

FAQ

Can tea made from oven-dried leaf be called pu'er? Under pu'er's national standard, pu'er must be made from Yunnan large-leaf sun-dried tea, so oven-dried tea doesn't meet that definition.

Does sun-dried tea always have a sunshine taste? The "sun-dried note" is how tea drinkers describe a sensation, and its strength varies from tea to tea. Clean sun-dried tea has a steady aroma and shouldn't smell stewed, smoky, or musty.

Is raw pu'er a green tea? The raw material for raw pu'er, sun-dried maocha, is made in a way close to green tea. But once pressed, raw pu'er slowly transforms in storage, so the tea world usually considers it separately from ordinary green tea.