Hi everyone,

I’m Andy, a tea enthusiast.

Have you ever noticed that when using a temperature-controlled kettle or reboiling water for tea,

the first infusion tastes fine, but by the second or third infusion, the flavor noticeably declines?

Today, I’d like to share why it’s not recommended to reboil water when making tea.

Why Do People Reboil Water When Brewing Tea?

When brewing tea, people often chat, work, or entertain guests at the same time.

The process isn’t always continuous, so the water cools down naturally.

Especially during cold weather, the temperature drops even faster.

So, many people get used to “reheating the water.”

While convenient, this habit can gradually affect the quality of your tea.

What Happens When Water is Reboiled?

Using repeatedly boiled water for tea can lead to:

- Increased bitterness and astringency

- Loss of aroma

- A dull and flat taste, lacking "vitality.”

The first brew may still taste okay,

but from the second or third infusion onward, the quality significantly drops.

Why Does It Taste Worse with Each Brew?

There are two main reasons:

1. Increased Water Hardness

When water is repeatedly boiled,

only the water evaporates;

the minerals like calcium and magnesium remain in the kettle,

making the water “harder.”

Harder water tends to extract more bitter and astringent compounds from tea leaves,

such as caffeine and catechins.

This results in a more bitter, more astringent tea with muted aromas.

2. Lower Dissolved Oxygen Levels

Once water boils, its dissolved oxygen content decreases.

Reboiling it reduces oxygen levels even more.

Water with low oxygen makes tea taste dull and lifeless,

lacking brightness and freshness.

Why You Shouldn’t Reboil Water for Tea?