Mineral salt additions for a dry stout

I'll be brewing a dry stout on Sunday during the Super Bowl and have been doing a lot of reading about mineral additions since my brewing water is about as close to distilled as you can get with a pH of 6.1. Brewing an IPA I would normally adjust all of my brewing water with gypsum to get the target Calcium and Sulfate concentrations. However, I have read that usually you only add chalk to the mash since it can cause your sparge water pH to be too high. So here are my questions... First, should I only treat the mash water, and, if so, at what concentration do I want the calcium, carbonate, hardness and alkalinity to be? Should the concentrations be large enough to treat the end volume of water or only to match the mash water volume? Will I need to treat any other water to add before the boil and after the sparge? Sadly, I have no way to monitor pH during the mash.

Thanks for any and all advice,

Greg

gyoder said:

I'll be brewing a dry stout on Sunday during the Super Bowl and have been doing a lot of reading about mineral additions since my brewing water is about as close to distilled as you can get with a pH of 6.1. Brewing an IPA I would normally adjust all of my brewing water with gypsum to get the target Calcium and Sulfate concentrations. However, I have read that usually you only add chalk to the mash since it can cause your sparge water pH to be too high. So here are my questions... First, should I only treat the mash water, and, if so, at what concentration do I want the calcium, carbonate, hardness and alkalinity to be? Should the concentrations be large enough to treat the end volume of water or only to match the mash water volume? Will I need to treat any other water to add before the boil and after the sparge? Sadly, I have no way to monitor pH during the mash.

Thanks for any and all advice,

Greg

Click to expand...

Without knowing the actual composition of your water it's difficult to make specific recommendations. However, if as you say the water is close to distilled here is the quick & dirty: I would add 2 tsp of calcium carbonate and 1/2 tsp calcium sulphate. Calcium carbonate is added to the mash because it dissolves poorly in plain water. The gypsum can be added to the sparge water if you want. If you have a water report you can look at the link below and using a brewing program make ion adjustments to your water to approximate a Dublin profile.

Water And Homebrewing

Palmer has nice section on it as well as some useful tools in his book here. I use that spreadsheet linked at the bottom of one of those pages. Just choose your target color (SRM) and input your source water. By choosing your target color you estimate the acidity of the grain bill (this way you don't have to plug in your 'target water' profile). Make sure to use the dropdown selection for 'Bicarbonate' instead of 'Alkalinity as CaCO3' if your water report gives Bicarbonate. Then plug in your mash volume and play with the salt additions and it will show you your resultant water at the bottom. Also...look at those Nomographs in that link above. I printed one out and drew out my Spring water and Drinking water (the spreadsheet does the same thing as the nomograph) and then my 'adjusted' water and it really helped to see the balancing act between effective hardness and Alkalinity with respect to residual alkalinity.

I just brewed an Oatmeal Stout and only treated the mash water...I just used straight bottled Drinking water (which still has 190 ppm Bicarbonate from my source) for the sparge. But I didn't get my pH strips in time to measure it.

FWIW, I'm pretty green on water chemistry but I did similar to what Big Ed said...most of my addition was CaCO3 (chalk) and it didn't dissolve until the grains were added (or it hit the mash). I then added some NaHCO3, CaCl, and MgSO4 to kind of balance everything out. Gypsum is probably more appropriate for a Stout though (as BigEd suggested).