Berries of the wild

[ERD50]

.... I use tap water that has been "aged" to allow any chlorine or chlorine-related items to evaporate. I used to use RO water but it lacks some minerals that yeast might want during fermentation.
....

It is my understanding that most/many municipal water supplies use chloramine, a more stable form of chlorine nowadays.

Home Water Treatment - How to Brew

Some city water supplies use a chemical called chloramine instead of chlorine to kill bacteria. Chloramine cannot be removed by boiling and will give a medicinal taste to beer.

Chloramine can be removed by running the water through an activated-charcoal filter, or by adding a campden tablet (potassium metabisulfite).

I'd also expect the commercial yeast nutrients (cheap and readily available) would provide any needed minerals? I've been using RO water for brewing for decades, and have not had any yeast problems.


Ahhh, wiki says that it does 'age out', but half-life is ~ 27 hours when boiling - I assume much, much longer if just standing.

Chloramine, like chlorine, can be removed by boiling and aging. However, time required to remove chloramine is much longer than that of chlorine. The time required to remove half of the chloramine (half-life) from 10 US gallons (38 l; 8.3 imp gal) of water by boiling is 26.6 hours, whereas the half-life of free chlorine in boiling 10 gallons of water is only 1.8 hours.[27]

And then...

https://www.morebeer.com/articles/removing_chloramines_from_water

Standing, aeration, and boiling will remove chloramines from water, but not very effectively. Water in my area (Fairfax County, Virginia) contains the equivalent of 3 mg/L of chlorine in chloramines, a fairly high level. Ten gallons of this water allowed to stand in a 25-gallon stock pot required weeks to lose chloramine down to the <0.1 mg/L level.

Unless you can measure the remaining levels, I would think a campden tablet is the way to go, cheap, easy, and almost instant.

-ERD50