Why treat the sparging water?

[mcdonald_ajr]

I am trying to get my mash ph lower, but am worried that the amount of gypsum needed will begin to be too much, as I live in a very hard water area. I have tried 30g in 38 litres, boiling for 30 minutes, but still get mash ph around 5.7. So my question is, what can't I put, say, 20g in just the water I'm using for the mash? That would be 10 litres. I would still boil the sparge water with, say 10g gypsum to get some of the chalk out. The result would be a lower mash ph. Does the sparge water have also to be a low ph? If so, why?

Thanks, Anthony

[Eric]

If your water is like mine, no amount of gypsum will get your initial mash pH down to where you want. Even boiling your water for 30 minutes then leaving it 24hours before decanting off from sedimented carbonates may still result in a higher than desired pH.
One answer is to use CRS which will avoid the boiling while turning some of the chalk into gypsum and some into calcium chloride but I'd advise you get a kit to test your water's alkalinity as you do this.
As for treating sparge water, the purists will tell you yes for many valid reasons. Certainly if you want to make a pale bitter beer that tastes like one made with softer water you will. I don't always do that, nor do my brews replicate what I can buy.

[fisherman]

Have you considered buying a Salifert Alkilinity test kit to test your water yourself or a water analysis at Murphy and son in Nottingham, Surley CRS and DLS will sort out your problem if you test your water.
Good Luck