Do I Need Gypsum?

(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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Eric
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Do I Need Gypsum?

Post by Eric » Mon Apr 27, 2009 3:57 pm

Just done my first AG brew after many years enforced layoff. The water was treated only with sodium met. to remove chlorides and a spoon of gypsum to 30 litres of water and then a further spoonful in the boil.

The mash was made using 4 Kg pale and 150 g crystal but pH was 5.8 after 10 minutes despite the gypsum. The water here is hard, I live on magnesian limestone, and in the past I would brew darker beers to achieve a better pH in the mash. I wonder if the gypsum doesn't readily dissolve because of the already high mineral content and just precipitates out? Then I wonder if there is already enough calcium in the water and maybe a drop of lactic acid would be a better course. What I do know is there is enough information on this site to answer my question but as my head is so full with reading that I'm totally mesmerised, I'll hopefully again take advantage of the great wealth of knowledge and assistance.

Our water company's figures are less than helpful, not even unit specified.

Alkalinity to pH 4.5 (Total) Calcium total Clarke German French


Min Ave Max Count Min Ave Max Count


6.9 205 300 12 56 69 87 4 hard 14 10 17


Can I ask, is there a simple answer or do I need to go the whole hog and get to grips with this subject at some stage soon?
pH.jpg
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Fermenting------- Billy Bowman's Binary Bitter.
Without patience, life becomes difficult and the sooner it's finished, the better.

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Eric
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Re: Do I Need Gypsum?

Post by Eric » Mon Apr 27, 2009 5:38 pm

Thanks again Chris.

I cut and pasted the figures and didn't realise that the layout would change when posted. Let's see if I can do better.

Alkalinity to pH 4.5 (Total)

Min 6.9
Max 200
Ave 300
Count 12

I think this means 12 samples were taken, the lowest 6.9 (couldn't be) and the highest 300.

Calcium total

Min 56
Max 69
Ave 87
Count 4 and no units given. ppm?


Hard. Hardness.......Clarke 14 German 10 French 17

These figures were obtained from the link at http://www.nwl.co.uk/Waterhardness.aspx for Sunderland east.


I tried to dissolve a teaspoon of gypsum in 3 litres of boiling water but a lot seemed to remain on the bottom of the pan. Maybe it was calcium carbonate but it was ever present once the gypsum was added. The water does vary but is always hard. At the other side of town there was never a drop of scale on the kettle elements in 24 years whereas here descaling is a constant chore suggesting it is never devoid of calcium. Nevertheless, it seems I should get to grips with the problem, just need my head to cool down first.

Sorry about mixing chlorides and chlorines, just shows how puddled I am and thanks for clarifying the calcium quantity issue.

The recipe was as you advised, I got 22 litres at 1042 and pitched the yeast at 8pm on Friday and it's still going at 20C but starting to wind down.
I should have done better on the mash but I am in need of more practice.
Without patience, life becomes difficult and the sooner it's finished, the better.

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Eric
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Re: Do I Need Gypsum?

Post by Eric » Mon Apr 27, 2009 9:59 pm

The 6.9 must be erroneous. I don't think you could get a low figure from any bore hole in this area.

I'll repeat the recipe doing as you say and see what happens. There were a few things that could have been done better and I will make those alterations, so it won't be a totally fair comparison. However, as the objective is good tasting beer and not a set of perfect figures its going to take a few trials anyway. If all else fails I'll add lots of roast barley and use Northern Brewer hops to make something a bit like the bought Guinness I'm drinking now.

Thanks again.
Without patience, life becomes difficult and the sooner it's finished, the better.

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