"A teaspoon of gypsum in the mash..."

(That's water to the rest of us!) Beer is about 95% water, so if you want to discuss water treatment, filtering etc this is the place to do it!
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Naich
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"A teaspoon of gypsum in the mash..."

Post by Naich » Wed Apr 27, 2011 2:03 pm

The quick and dirty way of getting reasonable brewing liquor for mashing is to remove the alkalinity by boiling or with CRS and to add a teaspoon of gypsum to the mash. According to my calculations, a teaspoon of gypsum (4g) added to 10L of mash liquor results in a Ca addition of 112ppm and a sulphate addition of 268ppm (http://www.howtobrew.com/section3/chapter15-4.html table 16)[1].

The addition is obviously to make sure there is enough calcium in the mash but the sulphate addition seems to be very high - over the recommended level of 150ppm for normal beers, and that's without the initial sulphate in the water and any added by using CRS (around 90ppm with my hard water). Adding 1tsp of gypsum to my mash would seem to give me a sulphate level of around 385ppm.

Would it be better to use a smaller quantity of gypsum and make up the remainder of the calcium addition using calcium chloride? I should say that I'm not trying to make a specific water profile, but trying to come up with a rough and ready treatment practice that will result in a fairly balanced liquor with all of the elements within (or not too distant from) the generally accepted limits.

[1] CaSO4 concentrations:
61.5 ppm.g/gallon Ca = 279.8 ppm.g/litre
147.4 ppm.g/gallon SO4 = 670.7 ppm.g/litre
1tsp = 4g

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Re: "A teaspoon of gypsum in the mash..."

Post by WallyBrew » Wed Apr 27, 2011 9:45 pm

Naich wrote:The quick and dirty way of getting reasonable brewing liquor for mashing is to remove the alkalinity by boiling or with CRS and to add a teaspoon of gypsum to the mash. According to my calculations, a teaspoon of gypsum (4g) added to 10L of mash liquor results in a Ca addition of 112ppm and a sulphate addition of 268ppm (http://www.howtobrew.com/section3/chapter15-4.html table 16)[1].

The addition is obviously to make sure there is enough calcium in the mash but the sulphate addition seems to be very high - over the recommended level of 150ppm for normal beers, and that's without the initial sulphate in the water and any added by using CRS (around 90ppm with my hard water). Adding 1tsp of gypsum to my mash would seem to give me a sulphate level of around 385ppm.
I think you should stop reading this stuff :)

4g of gypsum in 10 litres gives:

4000 / 10 x 96 /172 = 223mg/L of sulphate and....
4000 / 10 x 40 / 172 = 93mg/L of calcium

96 is ionic mass of sulphate
40 is atomic mass of calcium
172 is molecular mass of gypsum

assuming your brew length is 23 litres then the added sulphate and calcium would be 10/23 of those figures at maximum.

Where did the 150 for normal beers come from? Wasn't Burton famous for it's beers that contained substantially more than that?

Given your water is both hard and alkaline, if you just acid treat it to a low alkalinity (25 maybe????) you have sufficient calcium in your water that you do not need to make any further additions.

Any additions you do make of sulphate, chloride, calcium can go in the copper and the quantities you add should be your decision as to what your personal taste is

In order to add even more complications for you see this for even more sources of sulphate etc. viewtopic.php?f=9&t=39153#p435142

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Re: "A teaspoon of gypsum in the mash..."

Post by Naich » Thu Apr 28, 2011 10:47 am

Funnily enough, I originally got the numbers correct using the molecular mass (after initially missing the 2 H2Os off) and got the same numbers as you have written there. Then I found that page in HTB and thought I must have gone wrong somewhere, so I changed them :oops:

But anyway, I'll stop soon I promise :) I just need to understand it, then I can write the code and stop thinking about it. I should probably explain that I am not just doing this for my own water chemistry. I'm currently writing some code for a water treatment section of a web site I'm working on. The water chemistry section is only one small part of it and it doesn't warrant a fully-fledged calculator like Graham's. The object is to take the available data and come up with the additions needed to make suitable water for brewing a particular recipe. By "suitable" I don't mean a finely-tuned water profile, but merely liquor that won't make the beer taste horrible. The idea is that the user puts in what they know about the water (as a bare minimum, just the alkalinity) and the program "guesses" any additions needed to bring the water safely up to scratch. The plan is this:

1. User puts in alkalinity and calcium, if known. If calcium is not entered, it's guessed based on the alkalinity.
2. Calcium and magnesium (guessed from alkalinity) levels are checked and additions calculated, if needed.
3. Required RA calculated based on the recipe and numbers from step 2. CRS addition calculated.
4. Sanity check for stupidly high levels of sulphates or chlorides. Otherwise these are not really cared about.

This should get the mash into the right ball-park, pH-wise, and provide the major minerals. Additions assume the water has low mineral content to start with, but they should not produce excesses of anything if the mineral content is higher (outliers like Burton water excepted). If the user wants a more finely-tuned liquor they can use a proper calculator.

The standard advice here has been to CRS the RA down, add a teaspoon of gypsum to the mash and hope for the best, but my aim is to come up with a system that is somewhere between this and a fully-fledged calculator. I want to make sure that for a majority of people's water, the levels do not go outside the ranges recommended by Palmer (yes, him again :)) here. While his choice of numbers is probably fairly arbitrary, it's something solid for me to cling on to like a limpet being swamped by a tidal current of conflicting advice :)

So I'm thinking that in order to grimly hang on to Palmer's sulphate range of 50-150ppm, any calcium additions should be made with calcium chlorate as well as calcium sulphate, given that there is probably sulphate being added from other sources, as well as the unknown level of sulphate in the water to start with. My theory is that with additions of the right ratio of calcium sulphate to calcium chloride, along with a dash of magnesium sulphate if needed, I can come up with fairly balanced, general purpose liquor for a majority of water profiles, even when the original water profile (apart from alkalinity) is unknown.

Once I have some sort of algorithm written, the plan is to fine tune it by testing it with all the water profiles I can find to make sure it gives reasonable liquor for a majority of them.

Of course, what I really need is a web site where you put in your postcode and recipe and it comes up with the precise additions you need based on the most up to date water profile from the supplier for that region, but that's a project for another day...

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Re: "A teaspoon of gypsum in the mash..."

Post by GARYSMIFF » Thu Apr 28, 2011 2:15 pm

Whats wrong with Suck it and see lol

I always add one to Mash and One to Boil and never had a bad brew

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Re: "A teaspoon of gypsum in the mash..."

Post by Naich » Thu Apr 28, 2011 3:47 pm

GARYSMIFF wrote:Whats wrong with Suck it and see lol
Suck it and see is an excellent way of doing things. It's also known as experimenting and measuring the result :) But it is nice to know where you should start your sucking, if you see what I mean.

The way I see it, there are so many variables in brewing that unless you make a positive effort to get consistency, fine tuning to 3 decimal places is pretty pointless. I'm trying to make something that will start people off in the right sort of direction without needing to become too much of a water geek :D

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Re: "A teaspoon of gypsum in the mash..."

Post by far9410 » Thu Apr 28, 2011 4:01 pm

ok then for a simpleton like me, who is trying to resist getting into complex detail about water treatment at the moment. my water is slightly hard I think ( a small amount of scale in the kettle), what would be a safe and easy way of treating the water to get an improvement, even if not perfect. I currently use only a camden tablet, my brews have been pretty good so far, but am always looking for better ways.
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Re: "A teaspoon of gypsum in the mash..."

Post by Naich » Thu Apr 28, 2011 9:02 pm

The main thing is to get your mash pH right. You need to know the alkalinity of your water, either by getting a water report or by measuring it yourself with a kit. Once you know what it is, you can add the right amount of CRS to neutralise excess alkalinity if you need to. That is the most important part. It's not complicated and doesn't require much arithmetic. It's explained very well here - http://www.jimsbeerkit.co.uk/home_brew_ ... linity.htm
Last edited by Naich on Thu Apr 28, 2011 10:12 pm, edited 1 time in total.

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Re: "A teaspoon of gypsum in the mash..."

Post by far9410 » Thu Apr 28, 2011 9:20 pm

ok, read that, where do I get a salifert kit and how much? ta
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Re: "A teaspoon of gypsum in the mash..."

Post by Naich » Thu Apr 28, 2011 10:12 pm

You can get them off Ebay for a few quids - do a search for "salifert KH test" - you want the KH kit for testing the alkalinity. It's been pointed out to me that my previous post was wrong to imply that hard water is an indicator of excess alkalinity, so ignore that bit. I've taken it out to avoid confusion.

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Re: "A teaspoon of gypsum in the mash..."

Post by flytact » Fri Apr 29, 2011 12:46 pm

OK, now my head really hurts for a Friday morning. There was a reason I struggled through Chemical Eng. classes.
I use 5.2ph stabilizer from StarSan and sometimes add a teaspoon of salt to the mash.
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Re: "A teaspoon of gypsum in the mash..."

Post by WallyBrew » Fri Apr 29, 2011 2:14 pm

flytact wrote:OK, now my head really hurts for a Friday morning. There was a reason I struggled through Chemical Eng. classes.
I use 5.2ph stabilizer from StarSan and sometimes add a teaspoon of salt to the mash.
The makers of this used to have info on their website that was easy to find but seems more difficult today.

Their claim is that it locks your mash and kettle water at a pH of 5.2. Note that it does not claim to get your mash at pH 5.2

It is a mix of approx 5% sodium dihydrogen phosphate and 95% disodium hydrogen phosphate. It should give a pH of 5.2 in distilled water. Daab as he then was sent some of this to me and the rest was bought buy someone in Norfolk who I believe no longer uses it. The pH of this stuff at use rate in distilled water was 5.6. Doubt it would get better in most tap waters. At the ratios chosen by the manufacturer a small percentage change in the concentration of either component will shift the pH substantially. Draw your own conclusion as to the claims of the manufacturer.

EDIT - the first sentence in the last paragraph should read:-
It is a mix of approx 95% sodium dihydrogen phosphate and 5% disodium hydrogen phosphate
Last edited by WallyBrew on Fri May 06, 2011 3:58 pm, edited 1 time in total.

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Re: "A teaspoon of gypsum in the mash..."

Post by flytact » Fri Apr 29, 2011 4:02 pm

Maybe its more of a crutch to me. However, when I don't use it my efficiency drops by about 5%. I really don't measure, just dump what should be a tablespoon into my palm.
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Re: "A teaspoon of gypsum in the mash..."

Post by GARYSMIFF » Fri Apr 29, 2011 5:31 pm

Water Geek I like that but must admit since having a go with water treatments my beers are perceived to be better.

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Re: "A teaspoon of gypsum in the mash..."

Post by Naich » Fri Apr 29, 2011 8:31 pm

Of course the other way of getting good beer is to do it the old-fashioned way of brewing the type of beer that suits your water. You don't always have to pump chemicals into your water to get good beer. Having said that though, chemically altering the liquor does allow you to create better tasting beers that don't match your water. I like light hoppy beers, but my water is more suited to dark heavy ones.

If the whole water treatment thing seems a bit daunting (it does to me), then the one thing that will definitely help is getting the mash pH in the right area by getting the correct residual alkalinity in your liquor, as described in the Brewniversity link above. After that it seems to be a case of diminishing returns for the amount of headaches it needs to understand the chemistry.

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Re: "A teaspoon of gypsum in the mash..."

Post by far9410 » Fri Apr 29, 2011 8:49 pm

so, if I get a test kit, sort out the alkilinty with crs, then do I need to add burton crystals, gypsum etc.?
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