It is a widely spread custom that cold tap water is used for drinking and food preparation and hot tap water for the dishes and personal hygiene. But does it have to be like that? What if you are using hot water from the tap for drinking or cooking to spare some time? Have you ever wondered if it is bad to drink hot water from the faucet? If it is safe to use hot tap water for tea, coffee, pasta, or rice?

Can you make tea with hot tap water?

You should not use hot tap water to make tea, coffee, pasta, rice, etc. Generally speaking, you should not drink or use hot tap water to prepare any food or beverages. As stated in the study carried out by Lee [1], tap water, which was properly treated in water treatment plants, could get polluted within a hot water supply system. This may happen for many reasons. Some of them are listed below.

4 reasons why you shouldn’t drink hot tap water

Here are four reasons why you should not drink hot water from the faucet or use it for cooking.

• The heated water may cause the plumbing to release harmful substances such as lead and nickel [2].
• Cold water is fresher. Hot water stays in the plumbing system for a longer period of time to get heated. Longer stagnation time in the system may cause higher bacterial levels.[3]
• Hot water is exposed to more pollution sources since it passes through additional tanks or heating systems.[3]
• The level of microorganisms is higher in hot water plumbing. In multiple studies carried out by Lee [1], [4], it was found that the temperature appears to have an important impact on bacterial activity and also corrosion rate in the pipes (tested on PEX, copper, stainless steel, carbon steel and galvanized pipes).

The verdict

In my opinion, those four reasons are sufficient motivation to spend a little more time in the kitchen waiting for the water to boil.

Flush the faucet

To be sure that you are using fresh cold water, let the water run for a couple of seconds until it is cold.

How to reduce exposure to lead in drinking water

If you have pipes that might leak lead or other harmful substances to the water and you haven’t used the faucet for more than 6h, before using the water for drinking or cooking, always flush the tap first. Flushing the tap, as described by EPA [5], is running the cold water faucet for 15 – 30 s.

Such behavior might seem wasteful, but it doesn’t have to be. Just use the flushed water for your plants.

How to boil water quickly

To speed up the process of heating water, try using a portable single induction cooker (like this one – Amazon link). It is the fastest way to boil water that I know of. It is especially handy when cooking in large pots.

References

[1] Lee, Y. J. “An evaluation of microbial and chemical contamination sources related to the deterioration of tap water quality in the household water supply system”. Int J Environ Res Public Health. 2013. 10. 9. 4143-60. Link to the article.

[2] Andersen K. E., Nielsen G. D., Flyvholm M. A., Fregert S., Gruvberge B. “Nickel in tap water.”. Contact Dermatitis. 1983 Mar. 9. 2. 140-143. Link to the article

[3] Lee Y. J., Nam, S. “Investigation of nutrients controlling bacterial regrowth in a PEX and stainless steel plumbing water system”. Asian Journal of Chemistry. 2010 Jan. 22. 3. 2427-2441. Link to the article

[4] Lee Y. J. “Effects of temperature on corrosion and bacterial growth in water distribution pipes”. Asian Journal of Chemistry. 2008 Nov. 20. 8. 6535-6550. Link to the article

[5] United States Environmental Protection Agency. “LEAD in drinking water”. Retrieved 10/18/2019. Link to the document