Now that I have my water report for brewing, I am much more confident using salts to adjust my water chemistry.
I thought it'd be a cool experiment to brew three beers of three different colors using neutral (reverse osmosis) water and the same salt additions to see how the mash pH varies. Why? To get a better handle on this mysterious orb that is water chemistry. And because I'm a nerd.
As I mentioned in the water report post, the problem with Denver water is that the water comes from multiple treatment plants so the salt/mineral profile changes. It also varies seasonally.
Not good for brewing experiments where you're trying to hold the water constant.
Instead of using my home water, I bought RO, carbon filtered water from the grocery store. At $0.49/gal, I came in at under $5 for the entire batch of beer. Not bad. I think I'll go this route for all future batches.
The theory behind grains and their relationship to mash pH is that darker grains are more acidic and will lower the mash pH. That is all well and good but I like to see things for myself.
- Beer 1: Standard Bitter; 4 SRM
- Beer 2: Dunkelweizen; 16 SRM
- Beer 3: Dry Irish Stout; 36 SRM
- 100% reverse osmosis water
- 3 grams calcium chloride
- 2 grams Gypsum (calcium sulfate)
- 1.75 qts/lb water to grain ratio
- pH measured at room temperature 30 minutes into mash using Milwaukee pH meter
As you can see in the picture below, the beers cover a range from light to dark.
- Standard Bitter mash pH = 5.58
- Dunkelweizen mash pH = 5.49
- Dry Irish Stout mash pH = 5.37
Sure enough, they fell right where they were supposed to. The lightest beer, the Bitter, used 100% Maris Otter and had the highest pH. The Dunkelweizen used crystal malt and dark Munich which lowered the pH a tad. Finally, the stout with its large amount of roasted barley (10%) added the most acidity and had the lowest mash pH.
Groundbreaking discovery? Not at all. This is what was supposed to happen, and it's reassuring that everything fell into line.
Hopefully this practical example of how mash pH works explains things that may not have made sense from just reading about it.
Now you might be wondering which is the “best” mash pH. That one will have to wait. These all fall in the range of what is recommended (5.2-5.6), but two of the beers aren't ready yet so I can't determine any effects the mash pH had on the flavor. Even then it will be tough to tell a difference since they are all very different beer styles. The best way to do it would be to brew the same style at different mash pH's.
Knowing me, I'll probably do it.