Effects on pH step infusions

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caps_phisto

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Just wondering what the effects might be on mash pH during the step infusion mash schedule? More notably going straight from acid rest to sac rest. I am familiar with water chem and the Bru'n water sheet. However I can't seem to find any info on what if any an additional infusion would have on my mash pH. Especially after I have taken the care of using an acid rest to get the pH just right.

Thanks
 
I'd never really thought about it, but certainly the pH could easily rise if the water you add is of a higher pH and the water you add has an appreciable amount of alkalinity. The easiest thing to do would be to treat your sac rest infusion water to get it to a pH of about 5.5...then you don't have to worry about the pH as much.
 
input Bru'n Water with the total volume of water, after Sac infusions, after mashout infusions, etc. As long as you finish sub 5.5, you should be good throughout.

You can double check what the mash ph is at various points by adjusting the mash water volume in Bru'n Water, before Sac or mashout infusions.
 
input Bru'n Water with the total volume of water, after Sac infusions, after mashout infusions, etc. As long as you finish sub 5.5, you should be good throughout.

You can double check what the mash ph is at various points by adjusting the mash water volume in Bru'n Water, before Sac or mashout infusions.

That may work, but he wouldn't be checking what the mash pH is...he'd be checking a prediction. I don't know all of the chemistry involved, but I'd rather doubt Bru'n Water is designed to be used this way--so I kind of doubt it'd be as accurate as it normally is. I'd imagine this mostly depends on the alkalinity of his infusion water (EDIT: Also, obviously the pH of the infusion water will matter too.), as to how much the pH would be raised.
 
I guess I'll provide some further background.

I did the pH according to Bru'n Water and hit dead on the pH when I performed an acid rest. According to Bru'n Water all of my mash water was treated as one big lump (which I did), but I separated it out into two quantities, one to obtain acid rest (a smaller amount) and one to reach Sac rest (the larger). I didn't check the pH of the mash water at all.

I don't have my brewlog/Bru'n water sheet in front of me but IIRC it was 1/3 of water was strike to get to Acid and 2/3's got to Sac. However, both amounts were the exact same treated water and I hit the pH dead on first try at Acid rest.

So I guess the question overall would be, would there be a significant impact of using the same treated water over different infusions?

Thanks for the replies and discussion so far.
 
I guess I'll provide some further background.

I did the pH according to Bru'n Water and hit dead on the pH when I performed an acid rest. According to Bru'n Water all of my mash water was treated as one big lump (which I did), but I separated it out into two quantities, one to obtain acid rest (a smaller amount) and one to reach Sac rest (the larger). I didn't check the pH of the mash water at all.

I don't have my brewlog/Bru'n water sheet in front of me but IIRC it was 1/3 of water was strike to get to Acid and 2/3's got to Sac. However, both amounts were the exact same treated water and I hit the pH dead on first try at Acid rest.

So I guess the question overall would be, would there be a significant impact of using the same treated water over different infusions?

Thanks for the replies and discussion so far.

Well, first, I'm curious, why are you doing an acid rest? Is this a wheat beer or something? As far as whether you'll be OK with the already treated water...I'd imagine that depends on the treatment you've done. If you lowered the pH of your water to 5.5, then you should be fine. It's kind of hard to say otherwise.

You said you hit dead on the pH when you did an acid rest though...does Bru'n Water have some step mash calculator I'm not aware of? How do you know you hit the mash pH?
 
I do an acid rest because my pH meter can't operate at the Sac Rest temp. As far as 70F to 95F my pH meter can adjust to take the difference into account. So I always perform an acid rest. That way I can measure and take my time to get it right.

What I mean by "I hit it dead on" is that at acid rest I hit the pH Bru'n Water stated I should hit for "Estimated Room Temp pH". It doesn't have a step schedule pH estimator, hence my overall confusion/question about multiple infusions and pH.

Thanks again!
 
I do an acid rest because my pH meter can't operate at the Sac Rest temp. As far as 70F to 95F my pH meter can adjust to take the difference into account. So I always perform an acid rest. That way I can measure and take my time to get it right.

What I mean by "I hit it dead on" is that at acid rest I hit the pH Bru'n Water stated I should hit for "Estimated Room Temp pH". It doesn't have a step schedule pH estimator, hence my overall confusion/question about multiple infusions and pH.

Thanks again!

Ah, well, you should be aware that the published pH optimums (5.3 to 5.5 or 5.4 to 5.6) are at warm room temperature (25C). It's harder on your probe if you're taking readings at 95F, and the pH will actually be lower at 95 (...though it'll probably only be about .05 or so lower...but I'm just doing a rough, in my, head linear extrapolation from the .2 to .3 pH shift that have been reported at ~150F (sac temps)). So, for your next batch, skip the acid rest and do your single infusion. After about 15 minutes, take a small sample and cool it to 25C and take your reading. Also, you might consider reading AJ's pH meter sticky in this section of the forum.
 
Will do. What is a good way to adjust pH if I'm off at Sac temps? Also how much time do I have before it's too late and no adjustment will save my beer? As far as my meter is concerned it can operate between 60-122F with no issue, with only a 0.03 variance from room temp.

Thanks again.
 
Will do. What is a good way to adjust pH if I'm off at Sac temps? Also how much time do I have before it's too late and no adjustment will save my beer? As far as my meter is concerned it can operate between 60-122F with no issue, with only a 0.03 variance from room temp.

Thanks again.

Well, lactic acid or a some pre-crushed acid malt are an option to lower pH. Pickling lime is your best option for raising the pH. I don't personally change my mash pH during a mash. I record the pH and adjust next time I do the recipe. EZ water gets me pretty close, though. One other option, that I do frequently, especially with new recipes, is a 100 gram sample mash with the same water profile and grain to water ratio as the full scale mash.

EDIT: As far as how long is too long. I don't know a definitive answer. It's going to be pretty quick though, since a large portion of the conversion happens in the first 15-20 minutes with modern malt, which is why I record and adjust next time.
 
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