Calcium Sulphate 101

[Online Brewing Supplies]

This will be an ongoing thread dedicated to Calcium Sulphate in brewing.
Feel free to add any reliable content, please reference the source of the article.
Nev

Calcium Sulphate (Gypsum) is used to "harden" the process water or as a direct additive to the malt mash or kettle wort .The benefit comes from the Calcium ion.
The sulphate ion is harmful to the wort quality as a source of sulfur for the production of sulfur dioxide during fermentation, and forms hydrogen sulfide and other obnoxious sulfur compounds.

Gypsum is the cheapest and most accessible source of Calcium.

As already noted for Calcium and phosphate, the addition of calcium to the malt mash removes phosphates, the most desirable mash buffering agents.This can be overcome by withholding gypsum from the malt mash, its addition in water and cereal cooker formulations, and adding appropriate calcium to the "sparge water".

Gypsum added to the sparge water reduces solubility of husk poly-phenols in the malt mash. This improves wort and beer flavor, as well as the flavor and physical stability of the finished beer.
The flavor stability can be readily recognized by comparing the tastes of treated versus untreated worts and "glattwassers".

Phosphates from malt are the most important and effective buffering compound in the brewing process and are necessary for normal fermentation's.
[Hardwick W. A . handbook of brewing]

 

[Bribie G]

So the brewers at Burton on Trent (Calcium Sulphate and Magnesium Sulphate in the water supply) were doing it all wrong?
I note that the book was published in 1994 and appears to be out of print, Book Depository are out of stock.

 

[kahlerisms]

I welcome more posts on brewing salts - I've just started playing with them in the last six months. .
I'd suggest you have another skim over your post though, it's a little difficult to follow.

 

[Online Brewing Supplies]

Its here for $449.00 have seen it for half that,
http://books.google.com.au/books?id=0os_gIvG_ccC&printsec=frontcover&dq=handbook+of+brewing&hl=en&sa=X&ei=-JsAUaDGOcrMmAXsmYCABA&ved=0CDcQ6AEwAQ
It would appear that the BOT brewers could have done it better but back when they where at their peak they probably didnt have the science to know what was happening.
Only my thoughts, not science or accurate history.
Nev

 

[Online Brewing Supplies]

I welcome more posts on brewing salts - I've just started playing with them in the last six months. .
I'd suggest you have another skim over your post though, it's a little difficult to follow.

So is the book but quoted as written but probably a little pre reading missing.
Could not copy and paste so had to be typed and I am not the best at that.
Check out the link above it has a bit more text if you google "solubility of gypsum mash"
Nev

 

[manticle]

I find this idea interesting. Any idea of what ppm level of sulphate is likely to create problems and does it tie in with other recommended levels (Fix, Boulton et al etc)?

Much word in that text in regards to sulphate effect on bitterness perception and hop profile?

 

[drsmurto]

Sulphate does indeed get converted to sulphite and sulphide by the yeast as part of the synthesis of the sulphur containing amino acids, cysteine and methionine. To say this is harmful is odd given this process is essential to yeast metabolism. Yeast will only release sulphite or sulphide back into the matrix if there is insufficient nitrogen available to synthesise the amino acids. Which is why winemakers and brewers (sometimes) add a nitrogen rich yeast nutrient.

The problem with discussing the calcium ion by itself is that you ignore the complexity of the wort matrix and the synergistic effects of other ions; organic and inorganic.

 

[big78sam]

http://www.melbournebrewers.org/index.php?option=com_content&view=article&id=114:key-concepts-in-water-treatment&catid=48:ingredients&Itemid=103

This is what I refer to when looming at water treatment. It's a really good summary for the non chemist that contains info about Calcium sulphate and other salts for brewing.

 

[Online Brewing Supplies]

Gypsum added to the sparge water reduces solubility of husk poly-phenols in the malt mash. This improves wort and beer flavor, as well as the flavor and physical stability of the finished beer.

[Hardwick W. A . handbook of brewing]
Its the above that does not often get a mention but is of importance.
Nev

 

[mje1980]

Nev, how much in the sparge water per litre do you recommend?. I have pretty soft water, and usually add balanced amounts of calchl and gypsum for balanced beers if that helps.

 

[Thirsty Boy]

I think much (not all) of that first quote is about Calcium in general rather than specifically Calcium Sulphate

Specifically the reduction of mash phosphates (the badness of which is debatable because thats one of the mechanisms by which wort pH is reduced to desirable levels and I would have thought that was in fact good??) and also the notion of adding it to sparge water to reduce polyphenol extraction - this is just a mechanism to combat increasing pH as the sparge progresses and Calcium Chloride would do the same thing, as would reducing the pH of the sparge water by acidfying it.

That quote refers to gypsum (calcium sulphate) specifically for those purposes, mostly I think because it also states that Gypsum is the cheapest and most available source of calcium. So it assumes gypsum is what you will be using, rather than asserting that it is what you must use, to achieve the same end result.

One of the sources from which I draw this information/form this opinion is "Handbook of Brewing", Priest.F and Stewart. G, pp 107-121 but its in pretty much all the good brewing books in their water section.

 

[mje1980]

Ok cool, I might add some chl to my sparge water on my next mild. Might try a little bit, say 1/2 a gram per litre for a start and see if I can taste/notice a difference.

 

[Lurks]

http://www.melbournebrewers.org/index.php?option=com_content&view=article&id=114:key-concepts-in-water-treatment&catid=48:ingredients&Itemid=103

This is what I refer to when looming at water treatment. It's a really good summary for the non chemist that contains info about Calcium sulphate and other salts for brewing.

If I may. This document kicked off a long series of experiments and refinement in brewing salts that I've obsessed over the last couple of years. There's some good information there for starters.

If you follow the rough guide to minimum salts, it's quite conservative. The first order of business is to find out what your water is like. Mine is Cardinia reservoir in Melbourne. Melbourne Water do quite comprehensive water quality reports, some others in Melbourne I've seen miss out some things we care about like Chloride. Bottom line is that the highland reservoirs that service a lot of Melbourne are very soft indeed, enough that it's a real problem for mash pH and possibly even as far as yeast nutrient (my water has virtually no magnesium at all).

Armed with the figures from your local water, you can then use one of the various excel sheets that some folks have knocked up to calculate salt additions. This one is one I like in particular: http://www.ezwatercalculator.com/

The sheet above goes on mineral ranges given by Palmer. What I've managed to work out is this: the Calcium level and mash pH is the critical point. There's another load of stuff about the ratio of chloride to sulphate which some people claim has an effect of enhancing bitterness/hops and malt, respectively. Other brewers of note (with letters after their name) have called this into question.

Let's just suppose you believe that, then what you do is vary the ratio of calcium chloride and calcium sulphate according to the recipe, or just aim for something called 'balanced' and be happy. In general, calcium chloride seems more useful and you'll use more of it than sulphate.

For light beers, even the salts may not be enough to get the pH in the range and a bit of acid (lactic, phosphoric or acidulated malt) may be necessary. I've found you can get out of the pH range even on something of the gravity of Smurto's Golden Ale, say, and a touch of acid is needed.

This also means that's it's helpful to put all the salts in the mash, and not split up to the sparge water. Purely so that it has the best pH lowering effect (for light beers). Again the sheet linked above does a cracking job of helping make the choice between the two.

One oddity of that sheet is the pH range. I think there's more support for having a mash pH in the 5.2 region than 5.4 to 5.6, largely for other reasons which are beneficial to the brew.

Anyway, when I moved my mash to 5.2, balanced my salts using this sheet, it had a considerable impact on my efficiency, clarity of beer and even how fast the yeast kicked off (possibly due to a slight addition of epsom salts to get magnesium in range). This is of course anecdotal and I don't claim to be some authority on this or any other brewing topic.

 

[Online Brewing Supplies]

If I may. This document kicked off a long series of experiments and refinement in brewing salts that I've obsessed over the last couple of years. There's some good information there for starters.

If you follow the rough guide to minimum salts, it's quite conservative. The first order of business is to find out what your water is like. Mine is Cardinia reservoir in Melbourne. Melbourne Water do quite comprehensive water quality reports, some others in Melbourne I've seen miss out some things we care about like Chloride. Bottom line is that the highland reservoirs that service a lot of Melbourne are very soft indeed, enough that it's a real problem for mash pH and possibly even as far as yeast nutrient (my water has virtually no magnesium at all).

Armed with the figures from your local water, you can then use one of the various excel sheets that some folks have knocked up to calculate salt additions. This one is one I like in particular: http://www.ezwatercalculator.com/

The sheet above goes on mineral ranges given by Palmer. What I've managed to work out is this: the Calcium level and mash pH is the critical point. There's another load of stuff about the ratio of chloride to sulphate which some people claim has an effect of enhancing bitterness/hops and malt, respectively. Other brewers of note (with letters after their name) have called this into question.

Let's just suppose you believe that, then what you do is vary the ratio of calcium chloride and calcium sulphate according to the recipe, or just aim for something called 'balanced' and be happy. In general, calcium chloride seems more useful and you'll use more of it than sulphate.

For light beers, even the salts may not be enough to get the pH in the range and a bit of acid (lactic, phosphoric or acidulated malt) may be necessary. I've found you can get out of the pH range even on something of the gravity of Smurto's Golden Ale, say, and a touch of acid is needed.

This also means that's it's helpful to put all the salts in the mash, and not split up to the sparge water. Purely so that it has the best pH lowering effect (for light beers). Again the sheet linked above does a cracking job of helping make the choice between the two.

One oddity of that sheet is the pH range. I think there's more support for having a mash pH in the 5.2 region than 5.4 to 5.6, largely for other reasons which are beneficial to the brew.

Anyway, when I moved my mash to 5.2, balanced my salts using this sheet, it had a considerable impact on my efficiency, clarity of beer and even how fast the yeast kicked off (possibly due to a slight addition of epsom salts to get magnesium in range). This is of course anecdotal and I don't claim to be some authority on this or any other brewing topic.

I get my mash in the 5.2 pH range and all else falls into place from there. The kettle hot break is always much more if I have the mash pH at 5.2pH.
Nev

 

[manticle]

Ok cool, I might add some chl to my sparge water on my next mild. Might try a little bit, say 1/2 a gram per litre for a start and see if I can taste/notice a difference.

1/2g per litre sounds like a lot to me mje.

Everyone's water is different but with Melbourne (soft) water, I'm generally adding 4g total calcium salts to mash and 4g total to boil. That's for generally 22 L final vol, starting with around 32 L in the kettle.

Too much can be worse than none in my experience.

 

[Yob]

Ive been adding my Gypsum at a rate of 300ml of a 100g / 2lt solution (for a pale ale) to my HLT.. a bit of acidulated malt gets the mash to within a poofteenth of 5.2 every time for similar pale grists.

anything wrong with just adding it to the HLT and not the mash/kettle separately?

 

[Lurks]

Regarding salts in the mash vs sparge water. I measured my sparge run off and I found that after sticking all the salts in the mash, the sparge pH wouldn't rise to a worrying level. So from then on I just forgot about the sparge water and it comes out peachy.

 

[Online Brewing Supplies]

I think you need to consider sparge water pH in relation to polyphenol extraction in the mash/lauter, so some acidification or salt treatment is advised.
Nev

 

[manticle]

Depends a little on the water - I was under the impression that WA/Perth water is higher in temporary hardness (ie more alkaline) than places like Sydney or Melbourne.

 

[Online Brewing Supplies]

Depends a little on the water - I was under the impression that WA/Perth water is higher in temporary hardness (ie more alkaline) than places like Sydney or Melbourne.

Yes we run about 8pH where I am, yes it does depend on the water, I was generalising.
You need to know the pH of the sparge water first and if need be drop it below 7pH.
If I use RO sparge water I dont worry about pH as its usually around 5.4pH.
Nev