Climate, Insects, and the Living Art of Taiwanese Tea

The heat of summer and the blazing sun bring warmth to the land, prompting tea trees to sprout and grow. Yet this same warmth also draws swarms of insects, for whom tender tea leaves are a delicious delicacy. While the season fuels growth, it also presents a harsh survival challenge for the tea plant.

As extreme weather events become more frequent, Taiwan — situated in a subtropical monsoon and island climate zone — experiences especially visible effects: scorching summer temperatures, uneven rainfall across regions, and other climate anomalies have become increasingly common.

While humans and animals can often take shelter or migrate in response to such threats, tea plants must endure them in place. To survive insect attacks brought on by the heat, the tea plant produces bitter compounds like polyphenols and caffeine to reduce its appeal to hungry pests.

These substances are known as "secondary metabolites," a self-protective mechanism found in many plants through the course of evolution.

From this, we can understand why mainstream light-fragrance oolong teas in Taiwan — especially those harvested in the cooler spring and winter seasons or in high-mountain regions — tend to show fewer of these bitter compounds. With less insect pressure in these environments, tea trees need not defend themselves as intensely, and instead can focus on producing "primary metabolites" like theanine, pectin, and sugars. These contribute to a tea liquor that is smoother, sweeter, and more full-bodied.

However, with the ongoing impact of climate change, many mid- to high-altitude tea regions in Taiwan are seeing reduced yields due to extreme heat, inconsistent rainfall, and diminishing cloud cover. These environmental shifts have also affected farmers’ willingness to continue cultivating tea, becoming one of the key reasons for the gradual decline in Taiwan’s tea production.

Historically, during the Qing Dynasty and Japanese colonial period — when textbooks spoke of “Sugar from the South, Tea from the North” — Taiwan’s tea industry primarily produced oolong teas with heavy withering, deep oxidation, and a strong roasted character, rather than today’s common light-fragrance oolongs.

Tea leaves grown under hot climate conditions naturally develop higher levels of secondary metabolites, making them ideal raw materials for these traditional styles. The once-harsh bitterness can be transformed through careful craftsmanship into a tea full of rich, captivating flavors. Learning how to adjust processing methods according to the changing environment has now become a crucial skill for the modern tea artisan.

As consumer preferences shift over time — influenced by innovations in craftsmanship, packaging, technology, or the blending of cultural aesthetics — so too does the style and flavor of tea. In this way, tea is more than just a plant. Once it passes through the hands of the tea maker, the final brew becomes something alive — fluid, evolving, and full of life.