An Introduction to Water Treatment

An article by Ashley Carr

Water, Water Everywhere, Nor Any Drop to Drink!

Whenever we talk about ingredients for our recipes we inevitably talk about Malt, Hops and Yeast. All very important of course but with over 94 % of the final Beer being water it makes a lot of sense to think about and discuss this overwhelmingly vital component, because logically it must have a significant influence on the final outcome, whether we like it or not. Water chemistry and the role it plays in brewing is seen as rather daunting and way too complicated and after all you can still make Beer with what comes out of the tap anyway, can’t you?

Yes you can. And in East Anglia we are quite lucky in that our water is actually pretty good straight out the tap for brewing quite a number of styles. Except for one BIG problem. But before we allow it to make its entrance, a brief discussion about where water comes from will help to set the scene.

Before I do, a brief comment on the objective for all this. My brief is to give a simple and practical guide to what we need to know and do, not give a water chemistry lecture. Two reasons; One, I don’t understand it enough myself to adequately answer highly technical questions. Two, you don’t need to know it, you just need to know what to do and crucially a little on why.

Basically, water comes from two sources; Surface water from lakes, rivers, and streams and groundwater, which comes from aquifers underground. Surface water tends to be low in dissolved minerals but higher in organic matter, such as leaves and algae, which need to be filtered and disinfected with chlorine treatment. Groundwater is generally low in organic matter but higher in dissolved minerals. Here in East Anglia our water mainly comes from underground aquifers so has a lot of dissolved minerals in it.

Brewing water (liquor in Brewery parlance) affects the beer in three ways; It affects the pH of the beer, which affects how the beer flavours are expressed to your palate. It provides “seasoning” from the sulphate-to-chloride ratio. It can cause off-flavours from chlorine or contaminants.

Let’s deal with the last one first. Ridding the water of “contaminants” is simply done. According to Anglian Water our water has chlorine and chloramine, called chloramination, added to it to keep it fresh in our pipes and to stop bacteria growing in it, making it safe to drink. A freshly drawn glass from the tap usually has detectable levels with even a cursory sniff. However, chlorine is relatively volatile. Even leaving it standing overnight will remove quite a lot. As soon as you start to heat it even more is removed. This makes it much less of a problem, particularly if you prepare for a brew the day before and draw your water requirement at the same time. Chloramine however is not driven off by heat and can give a medicinal flavour. You will occasionally find brewers advocating running their water through a filter, usually a charcoal activated one. This is indeed very effective, as long as the filters are changed regularly enough. But it is an unnecessary expense if you don’t already have one as a Campden tablet i.e. potassium or sodium metabisulphite. ½ a tablet in your liquor requirement is more than adequate to deal with both. This is the absolute bare minimum water treatment and incidentally even useful for making kit beers.

Another discussion point that comes up from time to time on forums is water softeners. Please do NOT use water softeners as a source for your brewing water. Make sure your water isn’t permanently plumbed into one. They remove calcium and exchange it for sodium. The former we want, the latter we do not want. Whilst on the subject of filters of one kind or another you will bump up against the American obsession with “minerally” water and the recommendation you install a reverse osmosis water filter. The idea being the water is stripped of virtually everything in it, allowing you to build the exact water profile you are looking for. There is nothing wrong with this per se, particularly if you already have one. But the idea that this is ideal is false. Filtering through RO removes Calcium Carbonate and Bicarbonate……. the Alkalinity that I’m going to argue later is a bad thing, but bear with me, not always. Putting it back in is not a trivial exercise and for some beer styles you will have to do this. 

You can make any style of Beer you care to mention with the water we have coming straight out of our taps. Save your money. I will explain why in detail but we already have what we need in it, we merely have to adjust it and this can be done very simply and at very little cost. My other objection is that RO systems are dependent on their filter’s efficiency. From their very first use they are compromised and will continue to change the mineral content of what is left until the filter is changed. A minor point I grant you, but humans being what they are, the filters can be left way past the point they need changing, so who knows.

The point at which most of us who have investigated water start to struggle, is in handling alkalinity and the role of carbonate and bicarbonate. So I’m going to quickly unpick this without going into technicalities I don’t understand, as I flagged earlier.

Hard Water, Soft Water and Alkalinity

It is better to be in a hard water area than a soft water area unless you are only interested in brewing Pilsners, and even then you are still going to have to add calcium. So why is that? What makes hard water great is it is typically made up of calcium and magnesium, which we want. Unfortunately it also usually comes along with carbonate and bicarbonate, which we don’t want so much of. The latter is what is responsible for our bogeyman, the BIG problem mentioned earlier; alkalinity. Something we need to deal with in East Anglia because we have a lot of it.

An easy way to remember all this is to keep saying the mantra:

Hard Water Good – Alkalinity Bad! Hard Water Good – Alkalinity Bad!

So what did alkalinity ever do to us?

Because it can have a massive influence on arguably the most important moment in brewing, the mash! Mash chemistry is responsible for producing the wort the yeast is going to ferment. Get that wrong and there is nowhere to hide, no way of coming back from it. If it is slightly off you can still make a good beer, but get it spot on and you’re in the hunt to make a great Beer, a competition winning Beer!

The problem with alkalinity is its buffering capacity, resisting the grains acidification of the wort that shifts the mash pH into the “ideal” range. Don’t worry, not going to discuss pH today. The point is that alkalinity needs to be reduced for this to happen. Boiling will achieve something of what we want but it is too blunt an instrument, we can’t easily control by how much, and most of the time we want to do this because we are not brewing the same style of Beer every time we brew. Note that I have used the phrase reduced not eliminated, sometimes we actually need quite a bit.

Different grains have differing levels of acidification. Acidity reduces the buffering power of alkalinity and stops the pH rising. Calcium reduces alkalinity too, so we need to know what levels of that we have in our starting liquor for later calculations. Simply, lighter grains have less acidification power than darker grains. So light beers need more intervention, darker Beers less. Annoyingly some crystal malts are actually more acidifying than some darker grains, which muddies the waters, no pun intended. However, we have some rules of thumb that will help with this so don’t worry, the parameters, or range of alkalinity that suits certain styles is quite wide.

Typical alkalinity levels for most styles, includes the “flavour” ions:

 BitterStrong BitterLagerPorterMildWheatStout
Values in ppm

As you can see from the table, alkalinity up to circa 150 ppm can be quite useful. Our problem is that Anglian Water is typically circa 200 + and in my case 250. Grains alone, even in the presence of large amounts of calcium, and again round here that can be circa 140 ppm, isn’t always enough and if we are making a Pale Beer nowhere near enough to get the alkalinity in the right range to help the mash pH to fall to where it is needed. We brewers therefore have to intervene.

Suffice to say, we have to introduce an acid of some kind to do so. If you do nothing else other than get your alkalinity in the right range for the style you are brewing you will make a better version of that Beer. Make the same recipe with your water as is and then again after reducing the alkalinity to the right level and you will notice the difference. The lighter the Beer the greater the effect.

Water’s “seasoning”

So far we have looked at getting rid of stuff, either what we need to eliminate entirely or reduce to helpful levels. There is more in water than just problems, there is also the good stuff. If there is one good thing more than anything else it is Calcium, King of the Ions.

Calcium’s reaction with malt phosphates is a primary mechanism for the mash pH drop. It helps protect, stabilise and promote enzyme activity in the mash. It aids in protein coagulation, trub formation, oxalate precipitation, yeast metabolism and yeast flocculation. Calcium really is wonderful stuff! It can be added using calcium chloride or calcium sulphate (Gypsum) depending on the style you are brewing and whether you want a sulphate or chloride forward Beer.

Calcium is flavourless and doesn’t influence our perception of flavours but sulphate and chloride do. These are our “seasonings”. Just like salt and pepper in cuisine, sulphate and chloride can influence our perception of the Beer’s flavour. The sulphate anion accentuates hop bitterness, making it seem drier and crisper.

The chloride anion acts to make the beer seem fuller and sweeter. It has the opposite effect of sulphate. In fact, the sulphate-to-chloride ratio is a good way to gauge the effect of the brewing water on the balance of the beer. For example, a sulphate-to-chloride ratio of 2:1 or higher, will tend to give the beer a drier, more assertive hop balance, while a beer with a ratio of 1:2 will tend to have a less bitter, rounder, and maltier balance. It is just like seasoning your food; it helps accentuate the flavours that are there but will not fix a bad recipe. Water treatment is not a miracle cure for poor technique either. Learn to brew first, worry about water treatment second.

A couple of final thoughts on the subject of water treatment.

Historically, many famous beer styles were developed in conjunction with the water from the region, but you need to understand that brewers have been adjusting their water for hundreds of years. For instance, the water of Pilsen (where Pilsner originated) is very soft, free of minerals, and very low in bicarbonates. Brewers in this region typically add salts to raise the hardness in the water, mainly calcium. On the other hand, brewers in Burton-upon-Trent (famous for its IPAs) frequently pre-boiled their water to reduce the alkalinity.

So don’t assume that you have to use the exact water profile that you find on the Internet for Dublin, Ireland, if you want to brew a good Stout. The water profile for a famous brewing city may be a step in the right direction, but do your research and find out how the brewers of that region or style actually used their water to brew their beer.

Obtain a proper water report prepared for brewers. We recommend getting in touch with Neil Williams at Pheoenix Analytical. For £28 (as of December 2020) you will receive all you need to plug into the various water calculators you can find on the web. Water companies’ standard reports, like Anglian Water’s reports, are written to conform to statutory regulations, not to satisfy home brewers. The values are often reported as averages for the entire region, where some variation exists. I have had 2 in the last 7 years and found relatively small differences. Except in one crucial aspect, yep you probably guessed it, alkalinity. Most of the time it hardly varies but very occasionally it can be quite dramatic. Periods of drought and periods of heavy rain can alter the levels a lot. A simple aquarium water analysis kit for measuring alkalinity in FRESH WATER is all you need. Nerdy brewers amongst us invest in a Hanna alkalinity meter which is very handy but not cheap compared to the kits.


  • Water chemistry for brewing isn’t actually that hard to understand and there are very simple stages that can make a difference without a great deal of work, it adds no time to the brew day, particularly when carried out the day before.
  • Get a water report, you have to know where you stand.
  • Eliminate chlorine and chloramine with a simple tablet.
  • Test for alkalinity each time you brew, more importantly test again to make sure you have reduced it to the right range for style, taking into account the grains used.
  • Manipulate the sulphate and chloride levels to suit the style but more importantly your taste. To brew Beer the way you like it, is by definition the best Beer in the World, it requires an understanding of what you have and how to manipulate it so it gives you control. Remember if you can’t measure it you can’t manage it.
  • Steer clear of overly complex calculators that are pH driven. I recommend Graham Wheeler’s on Jim’s Beer Kit as a very good start.

Once you can control it you are now steering the ship, not the other way round. It still won’t make up for bad choices and bad technique so don’t think of it as the Holy Grail of brewing, more a final polish that makes a good recipe and good technique shimmer.

Author – Ashley Carr – Anglian Craft Brewers

One thought on “An Introduction to Water Treatment

  1. I do wonder that a water report is all fine and dandy but it is an average at best as water supply profile varies over the year . I still like RO because it gives me control, I her the point about changing filters and laziness in that way but it is up to the brewer to be conscious of that and keep checking the tds with a cheap tds meter . It is not complicated.

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