Brewing Clean Water: The metal-remediating benefits of tea preparation | Hacker News Reader

Brewing Clean Water: The metal-remediating benefits of tea preparation

pubs.acs.org

28 pointsbookofjoe10 comments

I drink a lot of tea, and I do think there's pretty good research on its health benefits (flavonoids and catechins, e.g.) but it's always funny to realize that its number one health benefit is that it requires boiling water (or almost boiling) before drinking it (not such a plus in the developed world, but for most of the history of tea drinking, quite significant).

I'd be curious to see how much metal adsorption we're talking, but Sci-Hub doesn't have this one yet...

https://news.northwestern.edu/stories/2025/02/brewing-tea-re...

Far more info, though it does lead back to the above link for downloading the paper

Thanks, that is a much better overview!

"We find that the preparation of black tea under typical conditions results in the removal of a meaningful fraction of lead from drinking water and that this value is highly dependent on steeping time."

I could only see the abstract, and this sentence seems to suggest it is for lead only? Is lead pollution still a relevant issue...?

Yes. In the UK at least. https://thewaterprofessor.com/blogs/articles/lead-pipes

I would like to know how much metal is leeched from the tea kettle during brewing and if the tea leaves would help mitigate that in addition to the metals present in the water itself.

What is really being measured? Seems they’re overlooking a significant variable in the research.

https://www.researchgate.net/publication/51485767_Tea_brewed...

Ok, so tea leaves can absorb some dissolved metals.

What could be better than that?

How about a drip coffee maker? A drip coffee maker creates little steam explosions to push water vapor to the top of the unit where it condenses and "drips" down over the coffee.

Since steam is being produced, in essence, distilled water is being used which if I understand the physics correctly, should be relatively free of metals.

Well a water filter could do it all better than that. I use a reverse osmosis system at home. The runoff goes to the garden

Drip coffee doesn’t use mainly condensed steam but uses the steam pressure to push the rest of the hot water through the pipes

Err... not so much. Most drip coffee makers are basically airlift pumps, where the air is from the liquid boiling to steam.

They're nifty little pumps, but they're absolutely not "distilled water" in the sense that you're imagining - It's not steaming up, condensing, and dripping. It's steaming up, pushing a bunch of liquid water up a small tube, and then burping the whole payload onto the coffee, including any and all impurities that are already in the water.

Example video here: https://www.youtube.com/watch?v=xV8vZqHd0ao

They're used lots on budget aquaponics/hydroponics/aeroponics setups because they can push water up surprising heights with nothing but a cheap aquarium air pump, or - in the case of a drip coffee machine - a cheap heating element.

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All of that said - you're still running that water through ground coffee and then a literal filter. I'd not be surprised in the slightest to find it also removes a lot of things.

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