Here is a copy of something I wrote for something else.......feel free to use as you wish
Water Treatments, Pale Beers and Bitters – a simplified approach (kind of….) for homebrewers.
By Mark Potts (Mr. Dripping)
I am invariably drawn to pale beers and if they happen also to contain a healthy dose of hops, then all the better in my opinion.
As a homebrewer I’ve tended to focus on this style of beer and for some time I struggled to brew anything that I felt was acceptable. Batch after batch was rejected by my palate, and it turns out that to succeed in making pale beers you do need a particular type of water, so this was something I needed to develop an understanding of….either that or spend the rest of my life brewing stout.
As a fledgling in my new hobby (or should that be obsession?) I started to do a bit of reading on water treatment on the tinterweb, and this is where it all started to get mightily confusing, with opinions ranging from “don’t worry about the water, just concentrate on brewing something consistently good”; to, “you will need to treat the liquor with acid” along with other chemicals and compounds that I had not encountered since my A-level chemistry days some 20-odd years ago.
Here is the result of what I’ve discovered over the years and the first thing I need to say is that you certainly do need to worry about what is in your water, particularly if you want to brew a good pale ale or traditional English bitter.
I mentioned earlier that I’d read in a few places the mantra…..“Don’t worry about the water, just concentrate on brewing something consistently good”.
Whilst that may be true in some cases, with respect to pale ales and bitters I believe that it is not true for the majority, and there is a risk that new brewers will become discouraged if they continually produce beers that are astringent and unpleasant to drink. Even at the most basic of levels it is important for brewers to grasp the fundamentals and therefore produce an acceptable beverage that can then be tweeked for improvements. So, how does the homebrewer go about achieving this?
Before I go any further I would point out that this is by no means a definitive text on the subject. My aim here is to provide some fairly basic information so that a brewer can hit an acceptable mash pH and produce a beer that is pleasant to drink.
The first treatment that all brewers should use on their brewing liquor is to add 1 crushed campden tablet per 20 gallons of liquor. This will remove any free chlorine and chloramine in the water - the presence of either will lead to the finished beer having an unpleasant medicinal taste often described by many as TCP like. This will liberate a small amount of chloride and sulphate in to the water that can effectively be ignored.
It is important that the Brewer (or Brewster) understands what he or she is initially dealing with. What is in the water that I’m using to make my beer with? This will determine how the water is treated, or indeed if it needs to be treated at all.
The 4 parameters I am most interested in are alkalinity, calcium, sulphate and chloride.
You may be able to get this information from the website of your water supplier. If it is not on their website, give them a call. I know many people who have done this, myself included and they are indeed very helpful.
There are regulations pertaining to potable water supplies and the supply companies test it fairly regularly; however the parameters that are of interest to the brewer are not always fully covered due to their being no formal requirement for the water companies to report them.
They do though offer a decent starting point from which adjustments to future brews can be made.
If you can’t get the information from the water company, then it is worth having your water tested using a professional service so you know exactly what you’re dealing with.
One thing that is worth pointing out is that water supplies can be variable depending on where you live and where the water is being drawn from. Dilution can also be an issue during times of heavy rain. Similarly, you may see an increase in mineral levels during times of drought or if water is ‘imported’ from another area to ease supply issues.
Also, the published data is often an average of values obtained throughout the year and I have seen some instances where the value for certain parameters is from one annual test.
It is for this reason that I would recommend that any brewer obtains a home test for alkalinity. I consider this the most important parameter when amending water for brewing.
Salifert test kits are popular among homebrewers. These are produced for the aquatics enthusiast and they offer a reliable way of measuring alkalinity before each brewing session and they are cheap with a kit that can perform 50 tests costing around £10.00.
Hanna Instruments also offer a small pocket meter. This is quicker than the Salifert and less fiddley, but will set you back in the region of £50.00 and you have to keep feeding it with the correct reagent at a cost of around £25.00 per 50 tests.
Calcium levels are also very important.
Sufficient calcium needs to be present to ensure a good mash pH is achieved and it is also an important co-factor in many chemical reactions that proceed during mashing and boiling.
It is also critical to good yeast performance, particularly flocculation once fermentation is complete.
It is recommended that brewing liquor should have at least 50ppm calcium and I usually prepare my liquor to have 150-200ppm.
The last two parameters I will cover in this article are sulphate and chloride. Here I am more interested in the ratio of the two ions rather than the concentration. For pale ales and bitters I am for a ratio of between 2 & 3:1 sulphate to chloride.
The pH level achieved during the mash is of great importance. It drives the pH level of the beer during boiling and fermentation and is also a critical factor in ensuring that no harsh tasting tannins are extracted during the mashing process.
I would recommend that any serious homebrewer purchase a pH meter or at the very least some narrow range pH papers so that they can test the pH of their mash.
The recommended range for mash pH is 5.2 – 5.8, measured 15 minutes after mashing in with a sample cooled to 25 degrees Celcius.
Darker grains help to lower the mash pH as does the presence of calcium.
Fighting against this is alkalinity; this raises the pH of the mash and can lead to the extraction of tannins from the grain husk. Add the tannins to the hop bitterness and you will end up with a very harsh tasting (almost astringent) beer that has a pronounced and unpleasant bitter bite.
A typical grist for a pale ale will contain very little (if any) darker malts and similarly in a traditional English bitter you will find only a small to moderate addition of darker grains.
When preparing liquor for brewing a pale ale I aim for an alkalinity level of 20ppm; for a bitter with a small amount of crystal malt I am happy with 30-40ppm alkalinity.
As previously mentioned I like to have calcium levels of 150-200ppm.
The water from my home tap generally has the following make up:
So let’s now look at treating this water to make a brewing liquor suitable to make a good pale ale with.
AMS is a product that is readily available to the homebrewer. It is a blend of hydrochloric and sulphuric acids and its addition to the brewing liquor will reduce alkalinity and add sulphate and chloride ions to it.
1ml of AMS will remove 183ppm of alkalinity in 1 litre of liquor, whilst adding 56ppm chloride and 89ppm of sulphate.
Aiming for a liquor of 20ppm alkalinity, I therefore need to remove 88ppm alkalinity per litre.
With some simple maths it is fairly easy to work out that I will need 0.48ml of AMS for every litre of liquor used.
This addition will add 27ppm chloride and 43ppm sulphate; bringing their levels up to 53ppm and 150ppm respectively.
To increase calcium levels a brewer will generally use calcium chloride or calcium sulphate or a mixture of the two.
1g of calcium chloride per litre of liquor will add 272ppm of calcium and 480ppm chloride.
1g of calcium sulphate (gypsum) per litre of liquor will add 233ppm of calcium and 558ppm of sulphate.
To my base liquor I need to add 64ppm to get the calcium up to 150ppm.
This can be done using 0.24g/l of calcium chloride whilst at the same time raising chloride levels by 115ppm.
Alternatively, I could use 0.27g/l of gypsum. This would raise sulphate levels by 150ppm.
If I use both gypsum and calcium chloride I can control the ratio of chloride and sulphate in the liquor.
In my case after treating with AMS at 0.48ml/l my profile is 20ppm alkalinity, sulphate 150ppm, chloride 53ppm and calcium of 86ppm.
Using 0.13g/l of calcium chloride gives 35ppm calcium and 62ppm chloride. The same addition of gypsum (0.13g/l) will add 29ppm calcium and 73ppm sulphate.
This gives a final profile of 20ppm alkalinity, 150ppm calcium, 223ppm sulphate and 115ppm chloride.
Before wrapping up this somewhat lengthier than anticipated article, a few things to bear in mind on how to add the AMS and salts.
Add the required amount of AMS to all liquor at the start of your brewday. It is important to keep the alkalinity of the sparge liquor low to stop the pH rising towards the end of the sparge. This is particularly important if you are fly-sparging.
Remember to mix well and re-test for alkalinity to ensure the acid has had the desired effect.
My usual practice for adding salts is to add them in proportion to the liquor being used at the time. I batch sparge, so will add the required amounts on mashing in, then again when adding the top up liquor for the first batch sparge with the remainder going in with the final liquor addition.
In closing I hope that you have found my article useful and not too complicated but most of all I hope that you can tailor this information to your own water and make better pale ales and bitters.
Calculations have been rounded to the nearest whole number.
AMS is also known as CRS.
Values for alkalinity reduction by AMS and values for added ions from salt additions are taken from LIQUOR TREATMENT 3 by Murphy & Son Ltd, document ref TECH/LT3 Revision 1.0, February 2006