Homebrew Water Treatment: An Introduction

What started with a free book for renewing my American Homebrew Association membership has turned into a two-month long quest to learn about homebrew water treatment.

What follows is my best attempt to share what I have learned. I will say now, some of this may be wrong, but it’s the best I can understand now and I’m relatively confident that it is correct. If I misstate something please leave a comment and I’ll get it corrected.

Water Treatment

First off, if you don’t homebrew and just like enjoying beer, but are still curious about beer and water you should read my previous post where I talked to local Cincinnati breweries about their water treatment.

Source Water

The most important thing to know about your water is where it’s coming from. There are three main sources, your tap, buying reverse osmosis (RO) water, or buying distilled water.

Luckily, Cincinnati and the surrounding area has pretty good tap water to brew with, after you remove the chlorine. Many water districts will give you a water report, though it may not contain all the brewing related info you need.

If you can’t find your local water report or if you want to be exactly sure what’s in there you can send a sample to Ward Labs for testing.

Homebrew water treatment
Thanks to @JasonB1217 for sharing this water report from Erlanger, KY.

One of the problems with water treatment is that there is no single Right Answer. All water can be slightly different even in different parts of Cincinnati and it will very likely change somewhat throughout the year.

J. Bromley also shared water reports from Northern Kentucky that he had done every 6 months for 2 years. Comparing all those reports there are some 20 ppm swings in certain minerals that would change what you needed to add to hit certain profiles. This means you really need to know your water profile before going further. This is also the upside to RO or distilled water as they’re basically a blank slate.

Water Treatment Minerals

There are many minerals and salts you can add to alter your water profile, I’m going to take a quick look at the most common ones.

Campden Tablets

If you’re using tap water this is the first thing you should do. From what I have seen all municipal water sources have some chlorine or chloramine in it and that absolutely must come out if you want to make a half decent beer. Luckily, to remove chlorine you can pre-boil it, leave it out overnight, or just add about a half a Campden tablet for 10 gallons of beer.

You can pick them up on Amazon for pretty cheap and any homebrew store worth their name should have it in stock.

If you are brewing extract batches of beer or extract + steeping grains you can feel free to stop here. The following applies mainly to all grain brewing and mashing.

Lactic Acid

After getting rid of chlorine getting your mash in the right pH range is the most important thing you can do for your water. The mash is one of the most crucial steps in brewing because it converts the sugar in the grain into a form that can easily be eaten by yeast. If your pH is too high or too low that conversion won’t happen properly. The goal is somewhere between 5.2 and 5.6 pH.

To get to your target pH you can add roasted grains, acidulated malt, or more commonly, a few milliliters of 88% lactic acid. Again, available on Amazon or any local homebrew supply store. Just add a few drops to the mash water before adding the grain and you’ll bet set.

Calcium Chloride

Calcium chloride (order it from Amazon) bumps up both the calcium levels and the chloride levels. Calcium is good in the mash to help enzyme and protein reactions for malt forward beers. Calcium also has the added benefit of lowering your pH. However, too much will lead to poor hop utilization so be careful. Meanwhile, the chloride helps boost flavor and fullness, so don’t use too much if you’re going for a thinner bodied style.

Calcium Chloride sprayed on the flat part of the road to prevent icing. Photo credit to Maury Markowitz

Fun non-beer fact: Many places use this to pre-treat roads for ice. So next time you’re low on calcium chloride before a brew and it’s about to snow just scrape some off the street. (Please don’t do this.)


Gypsum (Amazon), aka calcium sulfate, raises the calcium and the sulfate. From everything I’ve read and everyone I’ve talked to this is the last most common thing to add after Campden tablets, lactic acid, and Calcium Chloride. We’ve already talked about what calcium does for beer above. Sulfates are important for accentuating hop bitterness. It’s the higher sulfates in water from Burton-Upon-Trent that helped give the area the edge on IPAs back in the day.

Water Treatment Software

Campden tablets are pretty easy, half a tablet for 10 gallons and you’re good. But figuring out the right amounts of lactic acid, calcium chloride, gypsum, and any other minerals requires some advanced chemistry OR some very handy software.

There are a few different programs out there to help you treat your water. I’m only going to look at BeerSmith and Bru’n Water, the two most popular options, but EZ Water Calculator and Brewing Water are also good (and free) possibilities.


I like using BeerSmith because many of us already have it. To figure out what minerals to add you have to enter your grain bill, BeerSmith already has that because that’s where you build your recipe anyway! Also, crucially, it has a button to automatically calculate mineral additions.

BeerSmith Homebrew Water Treatment

Every other software I’ve seen for calculating water requires you guessing at how much of each mineral to add. You guess that you need 1 gram of gypsum and Bru’n Water tells you how it affects everything else, but only after you decide how much to add. BeerSmith on the other hand, tells you exactly how much to add, then you can play with it if you want. Available here.

Bru’n Water

This is the go-to software for serious and in-depth water treatment. It’s a complex series of spreadsheets that gives a very accurate and detailed calculation of water and mineral additions. Unfortunately, you have to guess at each amount of minerals to add to make changes and then tweak them to get a water profile that matches your goal. If you really want to get serious about water treatment Bru’n Water is the only way to go. Download it here.

What Do People Do?

Many people use their home tap water, add a Campden tablet to dechlorinate it, and then start brewing. The next most common step is a pH adjustment to get into the 5.2 – 5.6 pH range for their mash. A few more would add gypsum and calcium chloride. Very few people who I talked to do complete and unique water treatments for every batch they brew.

What Minerals Should I Add?

I’m side-stepping this whole bag of worms, sorry. Let’s call it beyond the scope (and word count target) of the article. Plus, there is no one Right answer. What minerals to add depend on your source water and the style you’re trying to go for. You should target the water profile of the area that style is from, like Pilsen or Burton-Upon-Trent? You also have to ponder if those brewers there treated their water in any way. See, a bag of worms, maybe I’ll write about it another day.

Serious Learning About Homebrew Water Treatmentbrewing elements water

What I’ve done here is just try to dip a toe into water treatment. If you want to take it a step further the best resource is the Brewing Elements book Water. Though you may want to freshen up on organic chemistry before buying it.

Okay, that’s all I got, let me know what I got wrong.

If you’re a homebrewer please leave a comment with what you use for source water and how you treat it!



3 thoughts on “Homebrew Water Treatment: An Introduction”

  1. Great summary post! I’ve started to dip into this world a bit, too. I’m out in the Los Angeles Basin, where the water is pretty much solid carbonates. I’m jealous of your water — we’re talking ~200 ppm bicarbonate in my typical tap water. So, it doesn’t need a lot of treatment (if any) for stouts/porters/IPAs, but a good pils or blonde ale can get pretty “mushy” unless you build up from scratch with RO.

    In terms of the water variation you describe (~20 ppm difference between reports), I don’t think I’d worry about that too much. That’s actually fairly minimal in my understanding, and realistically could even be within the realm of measurement error if you were building up your profile from scratch. I think it should be mineral (well, ion) dependent, but I wouldn’t worry too much until we’re talking more on the level of 50-100 ppm discrepancies between measurements.

  2. Just to clarify:
    >> it converts the sugar in the grain into a form that can easily be eaten by yeast.

    There is no sugar in grain. The mash activates enzymes that convert the starches in the malt into sugars that the yeast will consume (and, in turn, produce alcohol and CO2).

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