Expert: John Snyder - 6/18/2006

Question
Thanks!  So gypsum lowers PH, meaning makes it more to the acid side of the scale?  Hmm.  I know you can't tell what the PH of our tap water is (Albany, NY, old industrial area but surprising good tasting water).  But do you think that the water would necessarily requiring lowering the PH to improve fermentability?  Is "high" PH a common problem in tap water?  john white
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Followup To

Question -
Remind me again what exactly gypsum does for the brewing water?  Some older recipes say to add gypsum to every batch, but is this necessary or wise?  Thanks, john white.

Answer -
Gypsum is Calcium Sulfate.It adds calcium if the water is low in sulfate.It lowers Ph.Brewing salts should be used sparingly to make up for gross deficiences or overabundance of ions.It is necessary,just watch your sulfate counts.Proper mash Ph is very important.


any additional info required,let me know

         John

Answer
Drinking water PH is in the 6 to 8.5 range.Above 8.5 water hardness becomes great.Mash optimum PH is in the 5.0 to 5.5 range.4.5 to 5.8 is the working PH of the main enzyme groups during the mashing process.Mash PH affects enzyme activity as well as the flavor of the wort.Malt and brewing water combine to determine PH of the mash.Brewing salts,in this case,gypsum, insure proper mash conditions for best performance of the enzymes.

PH of local tap water,depends on the ground source;could be high(hard water)low(acidic)each of which cause problems,not healthwise. Check with your local water dept,they should be able to provide you with the necessary components of the water you are interested in.You could always use bottled water,and should be able to get an analysis of the bottled water from the manufacturer.Knowing the hardness and calcium content of water you are brewing with is important.
         again any further info needed,i will be glad to offer it