Originally Posted by 3 Dog Brew
BEER GEEK SPEAK AHEAD, USE CAUTION!
I had the same analysis done on the RO water:
Sodium ppm 3
Potassium ppm < 1
Calcium ppm < 1
Magnesium ppm < 1
Total Hardness, CaCO3 1
Nitrate ppm < 0.1
Sulfate ppm < 1
Chloride ppm 5
Carbonate ppm < 1
Bicarbonate ppm 10
Total Alkalinity 8
So, using my handy-dandy Palmer Nomograph, I've figured that to make a Red Ale with SRM 15-18, I should add (rounding for convenience) 1 tsp Baking Soda (NaHCO3) to 10 gallons of strike water to yeild 85ppm HCO3 + 91ppm Na AND add 1tsp Calcium Chloride (CaCO3) to the mash (after strike) to yeild another 28ppm CO3 + 19ppm Ca.
This should yeild mash pH of somewhere between 5.8 and 5.9
Does all this sound right?
I'm new to this whole water chemistry thing myself, so take my comments with a grain of salt...
I think some of your calculations and assumptions may be incorrect. Based off the data in Palmer's book, I get that adding 1 teaspoon of baking soda to 10 gallons of water will contribute 33ppm Na and 84ppm HCO3.
Adding 1 teaspoon of calcium CARBONATE (you wrote "chloride" in your post, but used the formula for calcium carbonate, make sure you are using the right stuff!) to a mash with 10 gallons of water in it would contribute 19ppm Ca and 28ppm HCO3.
Together, these would put your ion concentrations at:
Mg: <1 ppm
Ca: 19 ppm
This would give you a RA of about 1.73mEq/L -- or 86ppm on the top bar of the Palmer nomograph. If you were mashing only base malt, in theory you would end up with a pH a little over 5.8 when measured at room temperature. When brewing a red ale, the acidity of the darker malts would pull the pH down into the ideal range for mashing.
***However***, you probably aren't going to be mashing with the full 10 gallons, are you? If not, you have to be sure to calculate your ion contributions for the CaCO3 off of the volume of water in the MASH (assuming you are adding it directly to the mash as suggested). Personally, I only treat my mash water, so all of my calculations are based off of strike volume.
Another thing to consider is the lack of magnesium in your reverse-osmosis water. If you experience poor yeast performance, you might try adding a yeast nutrient to your wort to compensate for this deficiency. Then again, it may not be a problem.
The big message I've gleaned from my reading is that all of these super-fun calculations only provide you with a good guess for a starting point. Mash chemistry is too complex to accurately predict, so measure your mash pH and be prepared to adjust to reality.