top of page

Blog 117: How Do We Decide When to Harvest?

Since mid-April, our Wuyi oolong (Yancha) harvest has been dominating our tea blog and social media posts. In one of our previous tea blogs, we introduced our spring harvest schedule. (see Blog 102 and Blog 114 for more.) Today, let’s talk about some interesting details of our Wuyi oolong spring harvest.

Valley Brook Tea | Blog
Fresh leaves waiting to be harvested

As one of our most important events of the year, the spring harvest determines our tea-making activity for the rest of the year. Normally, the formal harvest starts in mid-April and ends around mid/late-May. The overall tea harvest and preliminary tea-making last about a month.

From the first sprout to fully matured, most of our oolong cultivars have a harvest window that’s fewer than 7 to 10 days. For oolong tea-making, we select broader, stronger and more matured fresh leaves. This is why in Wuyi mountains, oolong harvest is about 10 to 15 days later than black tea harvest.

Of course, the specific harvest schedule varies due with tea mountain field environment. For example, black tea harvest in Village of Tongmu (the birthplace of black tea) is also late because Tongmu’s high elevation and low temperature.

Valley Brook Tea | Blog
Our black tea production in Tongmu. (In the pic: our black tea tea maker Mr. Fu)

Because some tea cultivars mature early and some mature late, in our spring oolong tea harvest, we have 3 terms to describe the harvest timing: early harvest, mid-harvest, and late-harvest. Each term is about 10 days apart.

A standard oolong-leaf harvest takes a stem with 3 to 4 leaves (not including the bud). Our tea makers decide when to harvest based on “Kai Mian/开面”, which literally means how extended leaves are.

There are 3 types of “Kai Mian”: small, medium and large, and they’re defined by the sizes of the first leaf (from the top) and the second leaf (from the top). (See pic below)

Small “Kai Mian”: the size of the first leaf if smaller or equal to 1/3 of the size of the second leaf;Medium “Kai Main”: 1/3 of the second leaf < first leaf < 1/2 of the second leaf.Large “Kai Mian”: first leaf ≥ 1/2 of the second leaf.

Different cultivars are harvested with different level of “Kai Mian”. Strictly speaking, all cultivars can be harvested with medium “Kai Mian” because leaves at this stage contains more nutrients.

Leaves with small “Kai Mian” are tenderer and produce a stronger aroma. Large “Kai Mian” leaves have less nutrient contents, but can endure stronger roasting.

However, we don’t have to harvest all tea plants with medium “Kai Mian”. For example, Huang Guan Yin and Golden Peony can be harvested with small “Kai Mian”, and Shui Xian is better with a large “Kai Mian”.

Valley Brook Tea | Blog
Our tea makers' accurate estimation of the harvest day is crucial for the success of our tea production.

When spring tea season approaches, tea makers need to predict the harvest time based on the “Kai Mian” situation. Since each tea mountain field has its own size and harvest schedule, the demand for tea workers is never the same.

Our tea makers’ accurate estimation is crucial because it’ll directly affect how we hire and coordinate our workforce for the harvest. Commonly, we need to hire enough workers at least 7 days prior to the harvest. Any misjudgment can disrupt our plans and cause a financial loss.

After all, tea production is an agricultural activity, and human experience plays the most critical role. We hope this blog can help you better understand how we decide when to harvest Wuyi oolong (Yancha).

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!

This is a Valley Brook Tea original blog. All rights reserved.


bottom of page