Ask Mr. Wizard

Chlorinated water


Dale Engstrom • Salem, Oregon asks,

I recently moved from Montana to Salem, Oregon. When I brewed in Montana I used well water for my brews and there was never a problem — they were wonderful beers. Now that I am an “urban” brewer, I seem to have too many instances of beers fermenting with dry yeast that will not take off — the fermentations just sit there, never going into kräusen overnight (like they did in Montana). Could it be chlorine in my water? It may be my imagination but I think I even smell chlorine in the shower. I have tried adding a Campden tablet to my brewing water to little effect. I have thought of brewing with bottled water as a test to see if the local city provided stuff is the problem. Do you think this is a good approach, or do you see some other brewing aspect I am missing? How can I, other than giving up my job and moving back to Montana, get back to brewing wonderful beers?


You are one of those patients who comes in to the doctor’s office
with a cold and already have your mind made up about the cause! Since
you are convinced that you are stunting the activity of your yeast with
chlorine from the water, that is really all I have to work with to help
you out of your dilemma. To paraphrase your question: you were doing
just fine in Montana brewing great beers. The Big Sky State apparently
was providing you with a great environment and water supply for your
homebrewing hobbies. Then you moved to another beautiful state, one that
also has its unfair share of great breweries, and the brewing wheels now seem
to roll less evenly.

If you do have chlorinated water, and use the chlorinated water to
hydrate dry yeast before pitching, this could have an adverse affect on
your yeast. Fortunately, that problem is easy to solve, as you suggest,
by using bottled water, or water treated like bottled water that is
transported in something a bit friendlier than a plastic bottle, to
hydrate your yeast. If your water is heavily chlorinated and your shower
smells like a swimming pool you might want to check with your local
water utility to determine if there is something unusual happening down
at the water works.

Most commercial brewers who use city water for brewing use some sort of
chlorine removal method before using this type of water for brewing.
Some brewers use carbon filters and some use UV lights to remove
chlorine from water. At home, carbon filtration is probably your best
bet. Campden tablets can also be used to convert chlorine into chloride,
but it seems as though that method has not helped you.

I am sure you have changed more than your water when you moved from
Montana to Oregon. But before you consider other problems you should
satisfy your curiosity about the water. It’s pretty obvious you are
looking for an excuse to visit your former stomping grounds, so this is
your excuse. Go back to Montana for a weekend and when you return to
Salem bring enough water with you to brew your next batch of homebrew.
If the problem is solved you now know that a road trip is required
before each brew.

But what could be in the water in Montana that could actually help
yeast? My guess is zinc. Zinc concentrations in wort between 10–20 mg/L
is beneficial to yeast because zinc is an enzymatic co-factor. A brief
survey of publications about water tells me that it is entirely possible
that your water in Montana may have been a source of zinc. That may be a
far-fetched guess, but it does lead to a brewing suggestion: add some
zinc nutrient to your homebrew. The zinc nutrient I use is called
Servomyces, but there are other zinc sources you can add to wort, such
as zinc chloride.

When you moved you probably made more changes to your homebrewing
routine than merely changing the water, however, and my first guess is
that you may have changed homebrew supply shops. It could be that the
yeast you are now using is somehow different. Packaged yeast, whether
liquid or dried, has a shelf life. Perhaps you are using older yeast.
Another possible difference in your two brewing locales is temperature.

I hate to be short on ideas. I hope something here helps because it is
looking like you may have to return to Big Sky Country if you cannot
make your yeast happy!

Response by Ashton Lewis.