Water profiles and additions

[MSK_Chess]

In discussion with Martin it became self evident that we reduce the amount of Calcium sulphate to compensate for the added sulphate that we will get from additions of Sodium metabisulfite. It seems that we may also need to take into consideration adding a little more calcium than necessary to compensate for gallotannins.

It proved important to add extra calcium at mashing-in in order to compensate for the expected chelating effect of gallotannins.

http://********************/wp-content/uploads/2017/02/Officiele_tekst_voor_Brewing_Science.pdf

Now why this should be the case I cannot say for I am not a chemist but it presents certain problems when trying to get a balanced profile. On the one hand we are having to reduce the sulphate content to accommodate SMB (which affects the calcium content when using gypsum) and on the other we are having to increase the calcium content because of the use of gallotannins. What is a poor boy to make of it?

I raise the question because yesterday i brew'd a Vienna Lager and my efficiency was a little down, it should have been 1050 and was 1046 and I wonder if this was because of a reduced amount of calcium in the mash. I used a (Vienna boiled) profile with a mere 27ppm of calcium. Any thoughts or advice most appreciated - regards Robbie

 

[Big Monk]

In discussion with Martin it became self evident that we reduce the amount of Calcium sulphate to compensate for the added sulphate that we will get from additions of Sodium metabisulfite. It seems that we may also need to take into consideration adding a little more calcium than necessary to compensate for gallotannins.

It proved important to add extra calcium at mashing-in in order to compensate for the expected chelating effect of gallotannins.

http://********************/wp-content/uploads/2017/02/Officiele_tekst_voor_Brewing_Science.pdf

Now why this should be the case I cannot say for I am not a chemist but it presents certain problems when trying to get a balanced profile. On the one hand we are having to reduce the sulphate content to accommodate SMB (which affects the calcium content when using gypsum) and on the other we are having to increase the calcium content because of the use of gallotannins. What is a poor boy to make of it?

I raise the question because yesterday i brew'd a Vienna Lager and my efficiency was a little down, it should have been 1050 and was 1046 and I wonder if this was because of a reduced amount of calcium in the mash. I used a (Vienna boiled) profile with a mere 27ppm of calcium. Any thoughts or advice most appreciated - regards Robbie

Most of us at our main forum are making very minimal additions to our water. Many start with a Distilled or RO base and add enough CaCL2 to drive up the Ca to about ~40 ppm. Other than that, we are letting our sulfite dose drive the entire SO4 content of the water.

Other than that you will see doses of other salts to taste such as NaCl, MgCl, KCl, etc. but overall the mineral additions are very minimal. As far as the BTB/GT requiring the use of extra Ca, I haven't heard of anyone having issues but that doesn't mean they aren't there.

As far as your efficiency taking a hit, was your pH in line for the batch? Was this a recipe you brew often and the numbers deviated substantially from what you normally see?

 

[MSK_Chess]

My water is so soft there is no point in me using RO water, its on a par with Pilsen, comes from granite hills 1000 feet above sea level.

Yes this is what Martin advocated, simply foregoing the Calcium sulfate and using calcium chloride to boost the calcium content. Ph was a little low, about 5.1 according to my pH meter which I had calibrated. Third time I have brew'd this recipe. The problem for me was that I chose a profile that had only 15ppm chloride and i could not get it to balance without adding some calcium sulfate, but I had to reduce this because of the SMB. I will use a different profile next time I think because calcium was really low in the mash. Alas we live and learn!

The Brewing science pdf advocated adding some little extra calcium, 60ppm because of the use of gallotannins. I have no idea why this should be the case because quite frankly I don't understand the chemistry.

 

[Die_Beerery]

Your numbers were low because of your pH. 5.1 misses nearly all alpha activity. Bump that up to 5.4 to get alpha back.

 

[MSK_Chess]

Ok sure but I thought the recommended pH was 5.2?

 

[mabrungard]

Gallotannins (Brewtan) do chelate divalent ions like calcium. However, calcium does not really affect brewery efficiency. Remember, the Congress mash and its extract analyses use DISTILLED water with no salts added. Low calcium in your mashing water is not a problem. However, most of us like adding calcium salts to our brewing liquor for flavor's sake. The only real problems with low calcium are poor yeast flocculation and insufficient oxalate removal.

 

[MSK_Chess]

ok it was my understanding that calcium and magnesium ions in the water interacts with phosphates from the malt to acidify the mash. As i used acid malt perhaps lack of calcium is not a problem? So much to learn.

 

[Yooper]

Lack of calcium in the brewing water isn't a problem at all- the wort needs 0 calcium. The reason it's useful is that it helps prevent beerstone if the calcium level is over 50 ppm and it also enhances yeast flocculation and clearing. Since lagers are very clear from the lagering process, it's not a big deal to not have much calcium.

 

[MSK_Chess]

Soooo that clears that up then! Minimal calcium in lagers is no problemo! How interesting. It seems that Die_Beerery's suggestion for my sub optimal efficiency would make most sense, a low mash pH of 5.1 almost entirely misses out the alpha amylase - 5.3 to 5.6 being considered optimal for that enzyme. So I can expect my Vienna lager to be dry and thin, Should be interesting.

Thanks to all who contributed their knowledge and expertise.