Blog 31: The Principle of Wu-Yi Oolong Roasting

Updated: Oct 19, 2018

Recently, we received an email from a reader who’s observing oolong tea-making in the Wu-Yi mountains. In her email, she mentioned that when it comes to roasting, it seems that there are very different standards for teas that are similar. To understand the reason behind this, we need to understand the criteria that would affect the roasting procedure. Today, let’s talk about the principle of Wu-Yi oolong roasting. Before we begin, we recommend you read our previous blogs about Wu-Yi oolong roasting if you haven’t checked them out (Blog 1, Blog 2). They’d help you have a better understanding of today’s blog.


In general, the principle of Wu-Yi oolong roasting is that the roasting temperature needs to be balanced and equally-distributed. Any fast rise and huge fluctuation in temperature would result in a smoked and burned flavor. Wu-Yi oolong roasting pursues “low temperature and slow roast”. The specific roasting details of a tea depend on the grade of fresh leaves, varieties, level of roast and place of origin of fresh leaves. A good tea maker needs to master the temperature, timing, amount of tea leaves in roasting to perform a perfect roast. We’ve listed some most important criteria in roasting. Please keep in mind that these standards are interconnected. A good tea maker needs to consider all parameters to decide how to roast a basket of tea.


Rou Gui

Roasts for different grades of fresh leaves:


High-end tea usually uses premium fresh leaves from prestiges locations. These premium leaves normally cannot endure extremely high roasting temperature; otherwise they would lose all natural floral and aerial fragrance. Therefore, for premium leaves, we need to use a lower temperature, shorter roast period, thiner layer of leaves in the roast basket to preserve the original aroma and flavor. Low-end tea often uses low-grade leaves which are harder and firmer. These leaves sometimes carry a inferior smell. Tea makers typically apply a higher temperature and a longer roast period to clear the bad smell and taste. Mid-grade fresh leaves needs a temperature and a roast period that is in between the boundary of that of high-end tea and low-end tea.


Roasts for different Wu-Yi oolong varieties:


Different Wu-Yi oolong varieties have different leaves that have varying sizes and thicknesses. Therefore, leaves have various levels of heat endurance. Those Wu-Yi oolong that have thicker, broader and heavier leaves, like Shui-Xian and Mei-Zhan, generally withstand heat better, hence they should have a roast with higher temperature, longer roast period and thinner layers in the bamboo basket. However, for other teas with smaller and thinner leaves, like Huang Jin Gui and Qi-Lan, we’ll have to roast them with lower temperature, shorter roast period and thicker layers in the bamboo basket. Finally, tea leaves like Rou-Gui have medium sizes and thicknesses. For those teas, medium level of temperature and roast period are more suitable.


Roasts for different fermentation levels:


In our previous blogs, we’ve introduced how “the shaking” in Wu-Yi oolong tea-making affects the fermentation. The roasting process should also adjust its parameter according to how much “shaking” is done to the leaves. Tea leaves that are shaken more are roasted with higher temperature and longer roast period, and vice versa. The roasting procedure serves the result from the shaking process. A proper roast can bring our the color, aroma and flavor out of tea leaves.

Roasts for different places of origin:


Wu-Yi oolong can be categorized into 3 grades based on place of origin: Zheng Yan(正岩), Ban Yan(半岩) and Zhou Cha(洲茶). Zheng Yan has the best quality; Ban Yan has the second highest; Zhou Cha has the lowest quality. Thus, tea from Zheng Yan area can endure more roasts.


We hope you enjoyed today’s blog. As always, if you have any questions or suggestions, please leave a comment, tweet us @valleybrooktea or email us at contact@valleybrooktea.com. Please also follow us on Instagram @valleybrooktea and join our mail list to get our daily tea updates and our latest promotions! Finally, we have a independence day sale!! Use code: INDEPENDENCEDAY and get a 20% off on all products!