What are we doing when we brew tea over and over again? I personally believe that we are practising to get closer to balance. The so-called balance includes physical and mental aspects. We will start with the physical principle, that is, the three basic elements of tea brewing - water temperature, amount of tea and steeping time. These three elements are interlinked. No matter how the tea is brewed, it is all adjusted and experimented within these three elements.
The first thing to start with is the water temperature. As long as the water temperature is right, the tea will at least be half successful. There are a lot of things that can be discussed about water temperature alone. I will divide them into three different articles because some of them can only be noticed after a few years of experience in brewing tea.
In addition, I will focus on the oolong tea from Taiwan and try my best to include tea varieties from China. Oolong teas from these two places have very different brewing methods due to the complexity of tea tree varieties, craftsmanship, taste preferences, and cultural development. Taiwan's Oolong tea is mostly ball-shaped, while Mainland China's Rock Tea and Phoenix Oolong are strip-shaped teas. The taste of Taiwanese people is generally lighter than that of mainlanders. Therefore, the preference of amount and time, as well as the aesthetics of the tea are very different. Therefore, we cannot make a generalisation.
What does temperature do to the tea?
In this article, I will mainly explain three things, including how the temperature of the water determines the substances released from the tea, the speed of their release and the appropriate temperature for each type of tea.1. Substances
There are many complex elements in tea, they will be stimulated by different temperatures, and the three main elements that affect the taste are:a. Amino acids (including theaminic acid, glutamic acid, etc.) can increase the sweetness and aftertaste of the tea broth.
b. Caffeine, which brings bitter flavour.
c. Catechins, which bring astringency and some bitterness.
The graph shows the temperature at which they are released.
From the above chart, we can see that the amino acids are fully dissolved above 60 to 70 °C and there is not much difference even if the temperature is higher. This is why green tea is usually recommended to be brewed at this temperature, and also why cold brewed teas are sweeter. It is important to note that high temperatures close to boiling can destroy nutrients such as amino acids and vitamin C. Therefore, higher temperature is not necessarily good, but rather the right temperature to maximise the tea's strengths and modify its weaknesses.
Caffeine and catechins, on the other hand, require higher temperatures to dissolve. If the bitter flavour of the tea is too strong, you can lower the temperature to improve it. For example, avoid exceeding 90 or 95 °C and shorten the steeping time to adjust to your liking.
2. Water Temperature and Rate of Release
Imagine that you are turning on the faucet in your house. The higher the temperature of the water, the more water flows out, which means that the tea broth releases more substances in a certain period of time. On the other hand, the lower the water temperature, the lesser the flow, the lesser the amount of substance released from the tea.The following diagram can help you understand the difference in water temperature and release rate. In my own experience, the difference between 100 degrees and 95 degrees, multiplied by time, can double the amount of substances released.
In this beginner's chapter, I summarised three principles:
1. The higher the water temperature, the richer the tea broth will be. If the water temperature is low, less content will be released. But keep in mind – more is not always better.
2. You can use temperature to adjust what substance you want or don't want to release.
3. Temperature correlates with speed of release.
3. The Suitable Temperature for Tea
Now you understand the impact of temperature on tea. Below I will list the temperatures of teas, so you can easily start brewing a good cup of tea. The given values will apply to most tea brewing situations. Or if you can't get the temperature right at the beginning, you can use it as a base point to try. There are no absolutes in tea brewing. Depending on the variety of tea, the age and roughness of the tea leaves, the grade of the raw materials and the craftsmanship, there are many components to consider to find a suitable temperature for the tea. Keep in mind: Older tea leaves need higher / younger leaves lower water temperature. If the leaves are loose or broken, the tea leaves will be leached out faster so the water temperature can be lowered. So please keep a flexible mind and experiment with all possibilities. Often times we learn more from an unpleasant tea broth. In the end, we understand what factors cause a certain result, and we become an expert tea brewer.