There isn't a way to correlate water pH to color; you need to determine the Residual Alkalinity first. I would assume that using the 5.2 makes this moot, since it holds the pH (more or less) at 5.2 regardless of water profile or grain bill.
Assuming you leave out the 5.2: Here's a chart relating Residual Alkalinity to beer color (I apologize, I don't remember where I found this.)
RA (ppm) SRM
-60 to 0 5
10 to 60 10
60 to 120 15
120 to 180 20
180 to 240 25
Toledo water is good for beers in the 7-12 L color range.
To smooth out the hop harshness in your ESB you need to add Chlorides (easiest way is table salt, about 1 gram, or 1/6 tsp for a 5 gallon batch) to balance the Sulfates in the base water.
My starting point for all things water is John Palmer's How To Brew
, specifically Chapter 15 - Understanding the Mash pH
Here's a very good online calculator for water profile adjustments: Brewer’s Friend: Brewing Water Chemistry Calculator
For Toledo city water, the profile (from the 2007 Chemical Quality Sheet) is:
parameter as value
Total Alkalinity CaCO3 45
Total Hardness CaCO3 80
Non-Carbonate Hardness CaCO3 36
Bicarbonate HCO3 54.9
Calcium Ca 28.8
Magnesium Mg 2.5
Sodium Na 16.7
Sulfates SO4 23
Chloride Cl 0 (unlisted)
First, let me warn everybody that I'm not a chemist, so take everything I say with a grain of salt. If I'm making a mistake or overlooking something please
let me know so I can correct it.
Okay, disclaimer out of the way. Here are my notes:
- While the water pH is relatively high, it's not buffered much at all, so it isn't a problem for the mash.
- Mineral content is fairly low across the board, so this water is a very good starting point for any style; we can adjust with salts to get just about any residual alkalinity (determines optimal color) and Chloride/Sulfate ratio (malt/bitterness balance) we want.
- My calculations for residual alkalinity come to 23 ppm, which is perfect for beers with a color of 7-12L
- Both Calcium and Magnesium are low (recommended levels are 50 and 10 respectively,) so salt additions would benefit yeast health. I use Magnesium Sulfate (MgSO4, Epsom Salts) to raise the Magnesium levels and either Calcium Chloride (CaCl), Calcium Sulfate (CaSO4, gypsum), or Calcium Carbonate (CaCO3, chalk), depending on the style I'm brewing, for the Calcium.
- Chlorides are not listed in the report, so I assume there aren't any. Because of this, the Chloride/Sulfate ratio is zero, which enhances hop bitterness over maltiness. This is borne out by the hop harshness you experience in your ESBs. The good news is that Sulfates are very low as well, so you can easily adjust the balance by using a small addition of ordinary table salt. Adding 1 g (1/6 tsp) to the boil for a 5 gallon batch (assuming you start with 7 gallons pre-boil) will bring the ratio to 1/1, which is perfectly balanced between malty and bitter.
BTW, you can get gypsum and chalk at Titgemeiers