How Water Temperature Changes the Umami of Sencha

In my previous post, I explained what Umami is.

So, how can we bring out the umami in Sencha, Japanese green tea?

This time, let's talk about the science of tea!

Tea has some fascinating properties. Take a look at this graph.

There are three main components that contribute to the taste of tea:

Caffeine, which gives tea its bitterness

Catechins, which give tea its astringency

Amino acids, including theanine (L-theanine), which contribute to its umami

When you brew sencha with boiling water, all three of these components are extracted.

However, when bitterness and astringency become too strong, they can overpower the delicate umami, making it difficult to notice.

So, if you've ever thought, "Sencha is so bitter!", there's a good chance you brewed it with water that was too hot.

On the other hand, when you brew sencha with cooler water, less caffeine and fewer catechins are extracted. This allows the gentle umami of the tea to come forward.

This is also why Cold-brewed sencha is often so smooth and easy to drink, with very little bitterness or astringency.

So, what happens when we use warm water?

At around 70°C (158°F), you can extract a good balance of bitterness, astringency, and umami. This is one of my favorite ways to enjoy sencha.

Personally, I especially love sencha with a rich umami flavor, so I brew Yame sencha at around 60°C (140°F).

The amazing thing is that you can use exactly the same tea leaves and get a completely different taste simply by changing the water temperature.

Why not try a little experiment at home? Brew the same sencha at different temperatures and compare the flavors. You may be surprised by how much the taste changes!

And you might just discover a whole new side of Japanese tea.