Is Twice Boiled Water Really Bad for You and Potentially a Carcinogen?

TL;DR

Drinking twice boiled water is not bad for you, as long as your water source is safe to drink in the first place.

Transcript

Jeremy W. asks: Is it true that drinking tea made from twice boiled water is bad for you? There’s a rather persistent idea that “reboiling” water (i.e. boiling water two or more times and allowing it to cool in-between) while making a cup of tea is potentially harmful to your health, with some going so far as stating that regularly doing this even ... Read More

Key Insights

• 💦 Tap water contains impurities that are generally not harmful in the quantities found in common tap water.
• 💦 Concentration of impurities in twice boiled water is a concern but remains similar to unboiled water.
• 👅 Impurities from the kettle are negligible and unlikely to affect the taste or pose health risks.
• 😎 Dissolved oxygen levels in water are not significantly affected by boiling and cooling processes.
• 🥺 Claims that twice boiled water leads to cancer or other health issues are not supported by scientific evidence.
• 😂 The taste of tea made from twice boiled water is subjective and depends on personal preference.
• 💦 Public health agencies do not advise against drinking twice boiled water.

Questions & Answers

Q: Is drinking tea made from twice boiled water harmful?

No, drinking tea made from twice boiled water is not harmful as long as your water source is safe to drink beforehand.

Q: What happens to the impurities in the water when it is boiled?

Some impurities are removed during boiling, while others remain. However, boiling the water does not add any new impurities.

Q: Can twice boiled water expose you to toxic substances?

No, the claims that reboiled water exposes you to toxic amounts of substances like arsenic, fluoride, and nitrates are not true.

Q: Does twice boiled water affect the taste of tea?

The taste of tea made from twice boiled water is subjective and varies from person to person. Scientific evidence on the direct impact is limited.

Summary & Key Takeaways

• There is a misconception that drinking tea made from twice boiled water is harmful and can increase the risk of cancer.

• Boiling water changes its chemistry, removing volatile compounds and dissolving gases, making it safe to drink.

• Concentration of impurities is a concern with twice boiled water, but it does not add any new impurities.