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Blog 121: Determine the “Prime Time” of a Wuyi Oolong (Yancha)

In our previous blogs, we’ve been talking about why Wuyi oolong (Yancha) aren’t available right after the tea-making. Recently, some of our readers raised another question: how do tea makers know when a Wuyi oolong (Yancha) is ready for market?

To answer this question, we first need to revisit why Wuyi oolong (Yancha) can’t be sold right after the tea-making. To make a long story short, the reason is “the smell of the residual heat”, or Huo Qi/火气 in Chinese.

This “smell” refers to the unique scent attached to dry leaves after the roast. Actually, this is more than just one “smell”. It’s a collection of multiple odors including smells like roasted nuts, burned protein, or heated caramel. Of course, the most noticeable smell of all is smoke and fire.

Similar to the smell that we get in a Sunday barbecue, roasted Wuyi oolong leaves acquire this smell from the charcoal ash during the roast. However, different from that of a barbecue, the smell of roast on leaves will eventually die out with time.

We have to admit that fire is quite contradictory in Wuyi oolong (Yancha) tea-making. It gives Wuyi oolong’s distinct color, taste and mouthfeel, but it also prevents us from enjoying it right after the tea-making.

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The smell of smoke and fire comes from charcoals that are used in roasting.

Of course, if you really prefer the taste of this “residual heat”, you can still drink it. But most tea drinkers would rather wait until the smell is gone.

Since most respectable Wuyi oolong (Yancha) tea makers only sell their products when tea leaves no longer bear this smell, tea makers need to decide just when and how a tea qualifies as “without the smell”.

To check it, experienced tea makers usually inspect 3 major sectors: dry leaves, fragrances on the lid of Gaiwan, and fragrances in the tea soup.

First is the state of dry leaves. If we open a bag of tea and immediately discover a strong smell of smoke and fire, this tea is definitely not ready.

Secondly, we’d infuse the tea with a Gaiwan and sniff the inside of the lid. Hot water greatly enhance aromas that have a high boiling temperature. No smells from the “residual heat”can hide from hot water. The smell of smoke and fire first evaporates, then gets captured by the lid. If we discover a strong smell on the lid, we need to further inspect the tea soup.

Finally, tea soup is the last place where we can find the trace of the smell. If there’s the smell on the lid of Gaiwan, but not found in the tea soup, the tea can be considered as “free of the smell”.

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When leaves are just roasted, they contain a strong scent of the "residual heat"

Once a tea is free of the smell, it reaches its “prime time”.

The length of “prime time” of a Wuyi oolong depends on how heavily it is roasted. Generally speaking, lightly roasted Wuyi oolong have 3 to 6 months; medium roast have 6 to 9 months; heavily roasted have 12 to 18 months.

This duration is calculated from the moment a Wuyi oolong is considered as “free of smell”. In terms of exactly how long it’ll stay in prime time is also up to its storage environment, humidity, and temperature.

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"Fan Qing/返青" literally means "going back to green" in Chinese.

If a Wuyi oolong passes its prime time, it doesn’t necessarily mean this tea is going bad. “Prime time” is different from “best-before-date”. We can still drink it, except that its flavor and aroma will slowly retreat to a state called “Fan Qing/返青”.

“Fan Qing” literally means “returning to a state of green”, which refers to roasted leaves becoming damp after sitting too long in storage. Once “Fan Qing” happens, teas become less desirable. Eventually, these teas would become undrinkable.

In practice, one way to save these teas is to re-roast them. Unfortunately, this is simply not an option for most tea drinkers. Luckily, all good Wuyi oolong tea products are shipped when they just enter the “prime time”. As long as we finish them in time, we wouldn’t have the “Fan Qing” problem.

We hope you enjoyed today’s blog. As always, if you have questions or suggestions, please leave a comment, tweet us @valleybrooktea or email the author directly at Please also follow us on Instagram @valleybrooktea and join our mail list to get our daily tea updates and our latest promotions!

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