Mash pH w/ Russian Imperial Stout

[jnacey]

Hey guys,

I'm brewing up a Russian Imperial Stout next week with around 72% pale, 13% roasted malts, 25% caramel malts and other adjuncts. According to bru'n water, my mash pH comes out to an even 5.0. My current brewing water has an RA profile of 27.

According to everything I've read, you shouldn't really add chalk to bump up the mash pH. I'm not realistically willing to go out and buy a pH meter, so my question is should I add a little bit of chalk to bump up the pH or just roll without any water additions? According to my spreadsheet I would require a tsp of chalk to get into the correct mashing range. Here's my water report:

Ca - 32
Mg - 8
Na - 26
S04 - 12
Cl - 69
BiCarb - 66
Tot Hard - 113
Alk - 54
RA - 27

Thanks.

 

[ajdelange]

For starters you have 110% in the grain bill but making WAGS about what your malts might be like in those proportions with the water as described at 1.5 qts per pound of grain the mash pH will probably be more like 5.28 though one really can't put too much confidence in these estimates. Try some of the other spreadsheets and calculators and see what they give you. It is with these dark beers where there is uncertainty about the dark malts that you really need the pH meter.

I assumed a base malt with DI pH of 5.62 which is lowish though I have heard Maris Otter goes this low. Using a different pale malt with DI pH of 5.86 (high end) the pH estimate goes up to 5.32.

Going back to the more acid base malt: an addition of 110 mg sodium bicarbonate per L of mash water would get you up to 5.34 but would increase sodium by 30 mg/L so 50 mg/L pickling lime, which will raise pH by about the same amount might be a better choice of the two. Either is better than chalk if you want to raise pH some.

 

[jnacey]

Ahh, should have read 15% caramel malts. I was using more like 1.25qt/lb to make sure I have room in my mash tun. Beersmith always undershoots the volume of the mash for me so I just wanted to make sure I had room -- however this does serve to lower the pH.

I found some food-grade pickling lime on amazon that I might drop in to raise the pH if I go with the thicker mash.