Beginners Guide to Water Treatment (plus links to more advanced water treatment in post #1)

[strange-steve]

Since it's a topic that comes up quite a lot on the forum I thought I'd post a beginners guide to simple water treatment. Rather than delving into the complex chemistry, this is designed to give the basic information to get you started. There is lots of much more in-depth information available online if you’d like some further reading.

More advanced treatment here -

https://www.thehomebrewforum.co.uk/threads/more-advanced-water-treatment.71451/
https://www.thehomebrewforum.co.uk/threads/digging-deep-into-water-treatment.83931/

Just to add a couple of caveats to this, firstly I'm not a chemist so everything here is based on the work of much more knowledgeable people than I. But because I'm an amateur, I understand why this can be a confusing topic and so I've tried to take all the stuff I've read on the subject and simplify it into a manageable method. Secondly, this is just one way of approaching water treatment, other methods are available because even the experts on the subject don't agree on the "best" approach. However, this method works successfully for me. I'm not going to go through all the various options because it would take forever and ultimately be counterproductive for a beginners guide.

So let's get started:

The treatment of water for brewing can be broken down into 3 simple parts:

1. Removal of chlorine and chloramine
2. Adjustment of alkalinity
3. Addition of calcium salts and flavour ions

So let's look at each of these 3 aspects, but first some details.

What do I need in order to start treating my water?

There are a few things you'll need:
Salifert KH/Alk test kit
Salifert Ca test kit
Campden tablets
Either CRS [see note 1] or lactic acid
Gypsum
Calcium chloride
Bicarbonate of soda
A small syringe to measure the acids
Small scales with 0.1g resolution (search ebay for jewellery scales)


Do I need a full water report?

For taking your first steps into water treatment, no. The problem with water reports is that they generally don't have the information we require, namely alkalinity and calcium values, and even when they do, they are usually mean values which can be subject to quite substantial variation. Using the Salifert kits mentioned above is a more reliable method for now, although you may consider getting a proper analysis done in the future.

When do I add the water treatments?

Add all treatments to the mash water and sparge water before heating. Therefore the order of events is:-
- Fill your HLT with the required volume of water for the mash
- Treat it as necessary, stirring well
- Heat to strike temperature and dough-in
- Repeat for the sparge liquor.

Why is the mash water and sparge water treated separately?


You could collect the entire volume of water needed and treat the whole lot together (in fact if you full-volume mash this is exactly what you'd do) however the reason I suggest splitting them, is that sometimes the mash water is treated differently from the sparge water, but more on that later.

1. Removal of chlorine and chloramine

Why?

These are undesirable compounds found in some tap water supplies which react with phenols from the malt and hops to create a very unpleasant medicinal/TCP flavour which will ruin your brew even in tiny concentrations and no amount of ageing will remove it. If you use bottled water, this step can be skipped because it doesn't contain chlorine or chloramine.

How?

Most supplies in the UK don't contain chloramine (though there are a some which do) but chlorine is fairly common. There are various methods of removal such as carbon filtration, boiling, aeration etc. which are effective for removing chlorine but not chloramine. These methods can also be time and energy consuming, and so the easiest and quickest method is simply to use campden tablets [see note 2] which are very effective at removing both chlorine and chloramine.

Simply crush the tablet between two teaspoons, add to the mash/sparge water and give it a good stir to dissolve. Do this before you begin heating the water and the reaction will be complete by the time it reaches temperature. At typical chlorine concentrations, half of a tablet will treat around 35L of water, but don't be concerned about measuring out exact amounts. I normally just use a quarter tablet in the mash water and quarter in the sparge water.

Chlorine treatment may not be entirely necessary depending on your water supply, but it's so quick and easy to add campden that I recommend doing it if you have any doubt.


2. Adjustment of alkalinity

Why?

This is the primary reason for treating water. The purpose is to make sure the mash pH falls within the desired range of 5.2 - 5.8 which has a number of benefits such as improved enzyme activity, more efficient conversion, better hop extraction in the boil, better protein precipitation, improved yeast health and clarity of the finished product to name a few.

Something to bear in mind though, is that the pH of your water has practically no effect on the pH of the mash. This can be a source of confusion for many, but alkalinity is not the same as hardness or pH [see note 3], it is essentially a measure of how resistant the water is to change of pH. Therefore if your water's alkalinity is too high it will prevent the mash pH from falling to the correct range. However to complicate matters a little, the grain bill also has an effect. If there is a lot of crystal or roasted malts in the mash it will lower the pH, meaning that in general, dark beers require higher alkalinity water than pale beers.

How?

Well first of all, you need to know what your alkalinity is so that you know what adjustments are required. In order to do this, I strongly suggest that you get yourself a Salifert KH/Alk test kit [see note 4]. Using this, you can test the alkalinity of your water every time you brew, which may seem like overkill, but it can be surprisingly variable.

Now you know what the alkalinity is, you need to adjust it to roughly the correct level. Sparge water should always be adjusted to a low alkalinity, about 30 ppm or less preferably, but for the mash water, the following is a very general target to aim for [see note 5 and exception 1]:

For a pale beer - 20 ppm
For an amber beer - 35 ppm
For a brown beer - 75 ppm
For a black beer - 120 ppm

Don't worry about being exact, most of the time a mash will naturally end up pretty close to where it should be but this step will give it a little push in the right direction.

To reduce alkalinity, there are various methods of doing so, however I'm only going to discuss reduction through acid addition, specifically lactic acid and CRS, because it's the simplest way and both are commonly available in most home brew stores.

Firstly lactic acid; now this can have a flavour impact on the finished beer if used in large quantities, therefore I would recommend using it only for relatively minor adjustments. I would err on the side of caution and suggest a maximum rate of about 0.3ml per litre of water, because a lactate flavour can be unpleasant in some beer styles. Lactic acid added at 0.1ml per litre will remove about 52 ppm of alkalinity.

As for CRS, it is more flavour neutral in beer and so can be used in higher quantities. Adding CRS at a rate of 0.5ml per litre of water will remove around 95 ppm of alkalinity.

When using acid to treat the water, always be sure to add it before you heat the water to strike/sparge temperature, and stir it in well to release CO2.


If you have low alkalinity water you may have to increase it to get to the correct level which can be done by adding bicarbonate of soda (the stuff you bake with, aka baking soda or sodium bicarbonate). Adding 0.1g per litre of water increases the alkalinity by about 60 ppm [see note 6].

Part Two below -

 

[Chippy_Tea]

Due to a forum words per post limit this is part two of Steves edited version above, if you want to add a like make sure you like part one and not this as i will get the credit.

strange-steve

3. Addition of calcium salts and flavour ions

Why?

Calcium is an important ion in brewing; it is beneficial for enzyme activity during the mash and is essential for healthy yeast, good fermentation and clarification. The minimum level of calcium in brewing water is debated somewhat; 50 ppm should be considered a bare minimum, however some sources suggest 100 or even 150 ppm as a minimum. The malt does supply some calcium so I usually aim for around 100 ppm [see exception 2].

How?

Calcium is added in the form of gypsum (calcium sulphate) and/or calcium chloride. Which of these salts you decide to use is where the flavour ions, sulphate and chloride, come into play. Hoppy beers benefit from having a higher sulphate content, because this ion gives a dryer finish and it enhances the perception of bitterness in a highly hopped beer. Chloride on the other hand works better in a malty beer because it accentuates sweetness and fullness of flavour.

So put simply, use gypsum for hoppy beers like IPAs and pale ales and use calcium chloride for malty beers like brown ales and Scotch ales. If brewing a more balanced beer like an English bitter, use a combination of the two [see note 7 and exception 3].

The idea is to add enough of these salts to bring your calcium up to around 100 ppm. To do this you obviously need to know how much calcium is in your tap water to begin with, which you can determine by using a Salifert Ca test kit [see note 8]. You may well find that your tap water already has a lot more than 100 ppm of calcium, which is fine, you can still add a little of the appropriate salts for flavour purposes, but I probably would suggest somewhere around 200-250 ppm as an upper limit for calcium.

Use the following information to determine how much of each salt to add:

Gypsum added at a rate of 0.1g per litre adds about 23 ppm of calcium. Use at a maximum rate of 0.5g per litre.

Calcium chloride added at a rate of 0.1g per litre adds about 27 ppm of calcium. Use at a maximum rate of 0.3g per litre.


Putting it all together

So let's look at a couple of examples now which will hopefully make all this a little clearer. I've used slightly more difficult examples to show how they can be treated with the above method. These examples assume you have tested for alkalinity and calcium.

Brewing a stout with low alkalinity water

I'm using the values for Tesco Ashbeck water profile for this because it has a very low alkalinity of about 20 ppm and only 10 ppm calcium. So firstly, as you can see above, a black beer needs an alkalinity of 120 ppm so we need to add 100 ppm. As per the table below, you can see that adding sodium bicarbonate at at a rate of 0.17g/L is pretty close.

Now we need to increase calcium to around 100 ppm and because this is a malty beer, we'll use calcium chloride to do it. Adding calcium chloride at its maximum dosage of 0.3g/L will add about 81 ppm, which when added to the 10 in the base water, gives 91 ppm. Not quite 100, but close enough.

Now just do the simple maths; so if for example you have 12L of mash water that equals 2g of sodium bicarbonate and 3.6g of calcium chloride.

Say you have 20L of sparge water, that will require 6g of calcium chloride. Remember sparge water should always be low alkalinity, which it is in this example, so no alkalinity adjustment is required here.

Also don't forget to add the crushed campden tab, about quarter to the mash water and quarter to the sparge water.

Brewing a pale ale with high alkalinity water

For this example let's assume an alkalinity of 250 ppm and calcium of 100 ppm, and a 100% pale malt grist. So for a pale beer we want around 20 ppm of alkalinity which means removing 230 ppm. This is probably over the taste threshold for lactic acid so I wouldn't recommend using it for this, CRS would be a better choice. Looking at the table below, an addition of 1.2ml/L of CRS will reduce the alkalinity by the correct amount.

As for calcium, although the level is already at the recommended 100 ppm, I'd still suggest adding some gypsum to accentuate the hops. An addition of 0.2g/L will bring the calcium up to around 146 ppm while adding sulphate to make the hops stand out.

So plugging those figures in, a mash water volume of 12L would require 14.4ml of CRS and 2.4g of gypsum. For 20L of sparge water, add 24ml of CRS and 4g of gypsum.

Again don't forget to treat the water with campden tabs.

So that's it, pretty straight forward. Just remember the 3 main points of water treatment, remove chlorine, adjust alkalinity, add calcium salts.

Below, I have included a table to help you work out the required dosage of salts and acids, and below that there are some special cases which differ slightly from the general advice above.

Exceptions

1. Cold steeped or late-addition roasted malts

If you are making a dark beer, but not putting the roasted malts in the mash (eg. cold steeping them or adding at mash out or vorlauf) then obviously those malts won't have any impact on the mash pH and so should be ignored as far as alkalinity adjustment is concerned. In other words, if you were to make a porter with cold steeped roasted malts then you would use an alkalinity level appropriate for a pale or amber beer, depending on the grain bill.

2. Pilsner, helles, light lagers

When brewing these types of lightly flavoured beers, it may be a good idea to keep the mineral content low and aim for around 50 ppm of calcium. This is lower than the calcium content of many people's tap water, so it may be necessary to dilute your tap water with low mineral bottled (such as Tesco Ashbeck) or RO water to reduce the mineral content. You may find the beer takes longer to clear if using water with low calcium content, but the lagering process should deal with that.

3. New England IPA

New England IPA is an exception to the "gypsum for hoppy beers" suggestion, because despite being extremely hoppy, it tends to use chloride rich water rather than sulphate. Therefore calcium chloride should be used rather than gypsum as this adds to the full bodied juiciness common to the style.


Notes

1. CRS (also known as AMS) stands for carbonate reducing solution, it is a blend of food grade hydrochloric and sulphuric acids and is readily available from most HB stores.

2. Campden tablets are made from either sodium metabisulphite or potassium metabisulphite, it doesn't matter which you have, they can be used interchangeably. It is also possible to get metabisulphite powder which can be used in the same way (approx. 0.5g is equivalent to 1 tablet).

3. Hardness and alkalinity are not the same, but confusingly, they are often reported in the same units (ppm as CaCO3). So if you have a water analysis which says "hardness: 150 ppm CaCO3" it doesn't mean the alkalinity is 150 ppm. Hardness values aren't really very useful for us, so just ignore it. Get yourself a KH test kit and test for alkalinity yourself. Also note that ppm is the same as mg/L.

4. The Salifert KH kit is designed for aquariums, but is well suited to our needs as brewers. It can be purchased from eBay for about £8. It will tell you the alkalinity value in dKH, however the commonly used unit of measurement in brewing is ppm as CaCO3. You can convert dKH to CaCO3 by simply multiplying by 17.9.(See HERE for the "How to use Salifert test kits" thread.)

5. Be aware that the relationship between colour and mash pH, for various reasons, isn't quite so clear cut. For example crystal malts are actually more acidic than roasted malts. So this is only an approximation, but it should get you in the right area.

6. Sodium bicarbonate should never be added to sparge water, only to the mash, because sparge water should always be low alkalinity (<30 ppm). The main purpose of alkalinity adjustment is to get the mash pH correct, but using low alkalinity sparge water helps prevent tannin extraction from the grain during sparging.

7. These are only suggestions based on common practice, but don't be afraid to experiment with this. You may well find that you prefer a softer finish in your IPA from using more calcium chloride than gypsum, or that you like a crisp, dry finish in a malty style when you use gypsum. Think of this like seasoning food, there is no right or wrong way, do it according to your personal taste.

8. Often you can find out the calcium level from your water supplier, however it will be a mean value, and like alkalinity, it can vary by aconsiderable amount. Get a test kit and check it yourself.

 

[MyQul]

Lovely, Steve! I'm slowly but surely getting my head around water treatment. This and your answers to my questions on other threads have helped me out tons

Stickied! :thumb: (Edit:Chippy got there before me :lol:)

 

[strange-steve]

I didn't get a chance to proofread before posting yesterday, so made a couple of corrections. Please point out any other errors :)

 

[chuffer]

Cap doffed, great guide. Cheers!

 

[GermLish]

Thanks for the great post :thumb:

 

[Bigjas]

Brilliant post, thanks for sharing your expertise. I have only completed four All Grain brews and I am just looking at refining my skills and techniques to improve my finished beer. This will help a lot, thanks :thumb:

Jas

 

[timtoos]

Excellent guide Steve. Many thanks for posting

 

[Budgie]

Cracking post, Steve. This has made the whole thing so much easier to understand, and given me a definite starting point. :thumb:

 

[Kronos]

Very informative, thank you Steve.

 

[strange-steve]

Very informative, thank you Steve.

Thanks, hopefully it demystifies the subject a little.

 

[DoctorMick]

Possibly something worth mentioning with CRS/AMS, as well as reducing alkalinity it also increases chloride and sulphate which (from what little I know/understand) is something you may need to be aware of if you're aiming for a certain sulphate to chloride ratio (as recommended by Palmer and Kaminski).

 

[strange-steve]

Possibly something worth mentioning with CRS/AMS, as well as reducing alkalinity it also increases chloride and sulphate which (from what little I know/understand) is something you may need to be aware of if you're aiming for a certain sulphate to chloride ratio (as recommended by Palmer and Kaminski).

You are of course correct. The reason I didn't include that is for the sake of simplicity. Aiming for specific sulphate:chloride ratio adds confusion to an already confusing subject which is why I didn't go into it. Using calcium chloride for malty beers and gypsum for hoppy beers will swing the balance the correct way anyhow and the use of CRS won't make a huge difference to it.

FWIW CRS has a sulphate:chloride ratio of around 0.7:1 and if anyone wants to delve a bit deeper into the subject of brewing water they should read Martin Brungard's excellent article HERE.

 

[MrRock]

After sorting out a fermentation fridge with temp control earlier this year and starting to reuse yeast, I'm thinking water treatment should be the next thing I look at.

Trouble is I keep reading up on it and I've tried playing around with Bru'n Water and I get totally bamboozled.

I think this excellent guide by strange-steve is the first one I might have understood, but before I get carried away I'd appreciate if someone could tell me if I'm on the right track.

I've picked out some figures from my Anglian Water report, for things I've seen mentioned in this and other guides as possibly relevant.
I can post the while thing if it'll help.

Hardness: Very Hard
Total hardness as Calcium 125 mg/l
Total hardness as Calcium carbonate: 312.5 mg/l

Alkalinity (As Calcium Carbonate: 182 mg/l
Calcium: 112 mg/l
Chloride: 72.4 mg/l
Chlorine (free): <0.1 mg/l
Chlorine (total): 0.52 mg/l
Fluoride: 0.27 mg/l
Iron: <10 μg/l
Magnesium: 7.98 mg/l
Nitrate: 18.4 mg/l
Nitrite: <0.051 mg/l
Potassium: 9.24 mg/l
Sodium: 43.7 mg/l
Sulphate: 108 mg/l

My water report says Alkalinity (As Calcium Carbonate) is 182 mg/l, is this the same measurement/scale as the guidelines given "For a pale beer <20ppm"? i.e. would I be aiming to reduce alkalinity by 160ppm or so to hit 20ppm for a pale beer?
So if I'm using 32L of water for a batch (BIAB so all the water goes in at the start) I'd be looking to add:
half a Campden tablet
27.84ml (round up to 28ml?) of CRS (according to the Brupaks site 0.87ml CRS per litre gives a reduction of 160ppm alkalinity so 32L x 0.87ml/L = 27.84ml)
My water report states 112 mg/L Calcium so that should be ok as it's higher than the 100ppm suggested, or I could be aiming nearer 150ppm for the hoppy beers I like, in which case 6.4g Gypsum would take me to 158ppm (32L x 0.2g/L)?

 

[MrRock]

Is there a kind soul who could check my understanding and numbers in the post above to see if I've got this? @strange-steve ?

 

[strange-steve]

Is there a kind soul who could check my understanding and numbers in the post above to see if I've got this? @strange-steve ?

Apologies, I only just saw your post.

Ok so the relevant figures you've posted are:
182 ppm alkalinity (mg/l is the same as ppm)
112 ppm calcium
72 ppm chloride
108 ppm sulphate

Your water as standard is pretty good for a stout or porter but for pale ales then it would be beneficial to lower the alkalinity to around 20 ppm or so.

Your sums look correct, 28 ml of CRS and yes if you want to add some gypsum for your hoppy beers then go for it, 6.4 g will give you a high sulphate:chloride ratio which you want for a hoppy beer, though I probably wouldn't go much higher than that.

Another thing for you to bear in mind if you are brewing malty beers you should probably keep the calcium chloride additions pretty low, around 0.06g/L as a maximum. If the chloride and sulphate levels are both high then it can taste a little harsh and your sulphate is already quite high.

 

[geetee]

Well done that man!

I had been working on a guide to publish but I think you nailed it here.

if you are keen it is easy enough to set up a spreadsheet that will calculate each of these for you using a box where you input the target and another to input your local reading and brewlength. I just copy what I used last time as my water is fairly repeatable with low alkalinity.

 

[MrRock]

Apologies, I only just saw your post.

Ok so the relevant figures you've posted are:
182 ppm alkalinity (mg/l is the same as ppm)
112 ppm calcium
72 ppm chloride
108 ppm sulphate

Your water as standard is pretty good for a stout or porter but for pale ales then it would be beneficial to lower the alkalinity to around 20 ppm or so.

Your sums look correct, 28 ml of CRS and yes if you want to add some gypsum for your hoppy beers then go for it, 6.4 g will give you a high sulphate:chloride ratio which you want for a hoppy beer, though I probably wouldn't go much higher than that.

Another thing for you to bear in mind if you are brewing malty beers you should probably keep the calcium chloride additions pretty low, around 0.06g/L as a maximum. If the chloride and sulphate levels are both high then it can taste a little harsh and your sulphate is already quite high.

Awesome, thanks very much for taking the time to write the guide and check my numbers, as I said previously this is the first guide I've read that I've understood.

 

[Tomcat]

good info - thanks for that - at the point of delving into this aspect of brewing for the next brew so nice to read :)

 

[BeerCat]

So i am using Reverse Osmosis water i should have zero alkilinity am i right? I presume it should be fairly easy to adjust neutral water but still finding it hard. I have gypsum and epsom salts but so far all i have managed is to add 1g per 10l of gypsum for all my beers. Any help steering me in the right direction is much appreciated. :hat: