Chalk for water profile

[rich]

I'm brewing a stout this Sunday and will be tweeking my water a bit to get it closer to a Dublin profile. I need to increase my calcium by about 117ppm and Bicarbonates by 220ppm. Based on ProMash, 1.2 grams of chalk per gallon will get me real damn close.

What is a good source of chalk? There must be a houshold source that is ideal for brewing.

[bub]

yeah try using chalk...
BUB

[Danno]

Yep, chalk would work but I'd get food grade from a homebrew store. Remember to add it to the mash as it doesn't dissolve in water very well.

BTW, there's no need to go entirely to the Dublin extreme. Half way there will do wonders for the smoothness.