Kein Betreff

commonly known as gypsum.(try to get as clean as possible, not the
technical grade
but the food grade)
But first i's suggest try a mash without any additives, and measure the
ph in the
mash.(get some 4-7 ph teststrips from merk or so. I guess you can order
them at
any drugstore or get it at your homebrew shop)
Your ph should be around 5.3-5.5, if not add some gypsum 2 tsp stir well
and measure
again after 5 min.
This should only be needed with pale malts, if you add dark malts like
munich or
vienna or even darker, you should come into the right ph-range without
additives.
I have very hard water here, so i needed some more drastic (and
expensive) measures.
I demineralize 50% of my brewing water. Then i add some phosphoric acid
to my sparge
water. The phosporic acid is only needed whith pale malts.
There are other possibilities to reduce temporary hardness, like boiling
the water.
The problem that could result, is a water with not enough calcium.
Calcium is the most impotant ion in the mashing process concerning ph.
Your water is very low on phosphate that's why you add gypsum.
With my water i add calciumchloride, because i already have a high
phosphate content
but low on chloride.
If you like to know more i'd buy "Dave Miller's Homebrewing Guide". It's
the best
book i know in english covering everything from beginner to pro.
Hope it helps
Thomas