tea science and a cold morning's oolong

Making a cup of tea isn't rocket science, but when I'm not at the office making bucks for The Man, I like to tinker with the process for fun, the advancement of human tea knowledge, and some times even a better cup.

The basic principles involved may be expressed in the equation L+W+H*T=C where L is leaf, W is water, H is heat, T is time, and C is cha (the resulting beverage).

Although different teas come from essentially the same plant, varieties differ in climate, soil conditions, processing methods, etc. So different teas will have different surface areas and chemical compositions. So they are not all prepared in one unified way. For instance, some teas benefit from a hot rinse prior to infusion, to remove undesired materials, or to cause more leaf to be exposed to the infusion, etc.

The water used in tea introduces a wide range of different variables, mainly involving chemicals other than water molecules. Some of these are desirable, and others are not. The subject is a big one and will have to be explored in other entries.

Heat is simple. Apply heat to the water, which applies it to the tea. As heat increases, molecules in the water and the tea leaf become more active. And more active molecules lead to a greater number of points of contact between water molecules and leaf molecules in a given period of time. This is one factor in why some teas are rinsed to open up the leaf.

Choices in infusion vessel can dramatically affect conservation of heat. Factors include the material of which the tea pot is composed, whether the vessel is fully enclosed, whether the vessel is preheated, as well as the temperature and molecular composition of that upon which the tea pot rests. For example, if a tea pot rests in cold water, more heat may be lost in convection than if the tea pot were to lose heat to certain cold materials through heat radiation. This is another one of those big subjects one can explore further elsewhere.

Time is chosen in part based in large part on type of leaf used and the ratio of leaf to water.

This morning's challenge wasn't a challenging tea, but challenging temperatures. It was pretty chilly when I set out to make this oolong.

Since I planned a good bit of steep time, I wanted to add in a little protection against the cold.

So first off, I preheated everything in boiling water, including the frigid tea tray. But I also added a thick porcelain cup half full of boiling water to elevate the tea pot.

I gave the tea a really quick rinse to warm up and wet the leaves.



I touched up the preheat of the tea pot lid while pouring water for the steep. The only possible way this can have contributed to conservation of heat is in the creation of a water seal between the tea pot and lid, which I doubt is significant. But I figure it was harmless to do so, and keeping it in the hot saucer during prep was better than placing it on some cold surface, which I felt was undesirable.



I then left it all alone to do the real work without my intervention for about five minutes, resulting in a good cup of tea.