What effect, if any, does the pH level of my water have on OG?

  • Sounds like a good back story to that one.
    – brewchez
    Sep 8 '11 at 14:29
  • Brewchez, not sure a good story, but much longer. Really trying to figure out how we missed the OG on our last beer by so much. Expected 1.125 or so and had 1.080. I am new to your site and should have added information, but really wanted to know if PH levels would effect OG. We were going through our process to determine what was wrong, and I couldn't find the answer to that. I appreciate the answers below. Didn't think it was our problem. We have recently gone from brewing in pots to a three tier gravity system using half barrels. Our OG was fairly consistent using pots. Sep 8 '11 at 17:43
  • I have also recently re-started using a water conditioning system adding soda ash to my well water to decrease acidity We think most of our processes are good. For an imperial stout, we used 20lbs 2 row, 4lb crystal 60, 2 1/2lb chocolate, 1 lb flaked barley and 1/2lb black patent. Mashed at 154 for 60 minutes. Sparged at 168. Had sparge water left, the SG was 1.034 when we stopped. Just ran the above through BeerSmith and OG expected was 1.117. Changed the batchsize to 6 gal which is closer to what we have, OG went to 1.098. May have answered my own question. Still seems like a lot of grain. Sep 8 '11 at 18:07
  • 1
    First, it sounds like Denny's answer is most relevant to your question. Second, brewing dark beer definitely bring the possibility of pH issues. You may consider some research into mashing your non dark malts first, then adding the dark malts at sparging. Dark malts tend to lower mash pH so adding them late helps maintain a good mash pH for the conversion period. Lastly, if you just switched to half barrels it sounds like you may have a pot geometry issue. I'd check your dead space in your mash tun, or be sure you aren't channeling. Also trying to get those high OGs is tough regardless.
    – brewchez
    Sep 9 '11 at 11:18

It could have an effect it your pH was far enough off that you didn't get good conversion. But the pH would have to be WAY off to have much affect at all. In general, pH will affect clarity and flavor much more than OG.


None. Water of any PH has the same specific gravity.

  • Have to downvote this. The question was on the effect of pH of the OG [of the mash].
    – Poshpaws
    Sep 12 '11 at 16:00

I suppose that if you had a really weird water source there could be enough dissolved salts of some sort driving pH, and those dissolved salts may change the pH. Which in that case the water would probably be cloudy, smell funny, or taste really weird, possibly mineral like.

But in general, pH and gravity are not correlated under most conditions.

  • It might have to be a very extreme pH, maybe one that might not even permit fermentation? I would hope that most tap water would not have such extreme pH. Sep 8 '11 at 15:27

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