Mash PH------->Finished Beer PH

[mongoose33]

In his new How to Brew book, John Palmer says that finished beer PH should be adjusted by the mash PH, as it carries through. But a recent Brulosophy exbeeriment that evaluated the difference between a normal and a very low mash PH showed almost no difference in PH in the finished beer, which in my mind contradicts what Palmer says in his book.

When I find discrepancies like this, I need to resolve them, and in doing so, I almost always learn something important. I sense that here.

Of course, there are many things in the Brulosophy exbeeriment that could account for the results: measurement error is one. That explanation loses some validity when one looks at finished FG, which shows a pretty big difference between the two batches.

So--does finished beer PH matter that much? Is it truly something the yeast will determine for itself? Can it be influenced by Mash PH at all? Anyone focusing on controlling finished beer PH? Are there things here I'm not seeing?

 

[goodsuds]

I think maybe we need Marshal and the Brulosophy guys to do an exbeeriment comparing a high mash pH brew with a normal mash pH. I'd be curious to see if using the same yeast strain with the same alcohol tolerance would result in a more attenuated beer.

 

[ajdelange]

Palmer himself put up a slide at an MBAA meeting that indicated that while mash pH has a small effect on beer pH it is mostly the yeast strain that sets wort and beer pH.

 

[mongoose33]

In his new How to Brew book, John Palmer says that finished beer PH should be adjusted by the mash PH, as it carries through. But a recent Brulosophy exbeeriment that evaluated the difference between a normal and a very low mash PH showed almost no difference in PH in the finished beer, which in my mind contradicts what Palmer says in his book.

I think maybe we need Marshal and the Brulosophy guys to do an exbeeriment comparing a high mash pH brew with a normal mash pH. I'd be curious to see if using the same yeast strain with the same alcohol tolerance would result in a more attenuated beer.

I've thought about doing something similar, both to replicate the original above, as well as doing high versus normal.

 

[BigGutHeavyD]

Adjusting the mash and boil pH values does have beneficial effects on the beer.

Adjusting mash pH is well documented to have many positive effects:
http://braukaiser.com/wiki/index.php/How_pH_affects_brewing

Adjusting the boil pH also has positive effects:
- coagulation of hot-break
- hop utilization and the quality or harshness of bittering control

http://beerandwinejournal.com/proper-boil-ph/
http://braukaiser.com/wiki/index.php/How_pH_affects_brewing

Having a proper mash pH does not necessarily guarantee a proper post boil pH in two different worts.

http://www.germanbrewing.net/docs/Brewing-Bavarian-Helles.pdf
https://www.homebrewtalk.com/showthread.php?t=627708

IIRC 5.1 - 5.2 is recommended by the various brewing texts.

Controlling and standardizing the post boil pH is a starting point to determining the finished pH of various yeasts.

 

[mongoose33]

Adjusting the mash and boil pH values does have beneficial effects on the beer.

Adjusting mash pH is well documented to have many positive effects:
http://braukaiser.com/wiki/index.php/How_pH_affects_brewing

Adjusting the boil pH also has positive effects:
- coagulation of hot-break
- hop utilization and the quality or harshness of bittering control

See, this is the part that I'm trying to reconcile. In the above source is this quote:

The pH of the mash should not fall below 5.2.

http://beerandwinejournal.com/proper-boil-ph/
http://braukaiser.com/wiki/index.php/How_pH_affects_brewing

Having a proper mash pH does not necessarily guarantee a proper post boil pH in two different worts.

http://www.germanbrewing.net/docs/Brewing-Bavarian-Helles.pdf
https://www.homebrewtalk.com/showthread.php?t=627708

Then you say this:

IIRC 5.1 - 5.2 is recommended by the various brewing texts.

So right off the bat we have contradictory "advice." Which should I follow? The advice from the Braukaiser source, which says don't let pH fall below 5.2, or the "various brewing texts" that say 5.1 - 5.2 is recommended?

This is why I started this thread. I see contradictory advice, and furthermore, I've mashed from 5.08 to 5.48 and every time the beer has been excellent. Now, maybe I'd get more refined this or that in a lower (or higher) pH mash, but it doesn't seem to matter all that much. I brew a Rye beer that is excellent and it typically is in the 5.3-5.4 range. Tastes great!

So--with what I posted earlier in the thread about the Brulosophy exbeeriment, and the evidence from it suggesting that it's difficult to control post-fermentation pH with mash pH, what advice do I/we follow?

 

[BigGutHeavyD]

5.1 - 5.2 is regarded as a proper post boil pH. 5.2 is regarded as the lowest mash pH. There doesn't appear to be any contradictions. Of course being a natural process, mother nature tends to reconcile itself.

 

[ajdelange]

There seems to be some misunderstanding of the role of mash pH in brewing. It is important, very important, that the mash pH be in, generally, the region 5.4 - 6.5 as measured at room temperature, for the best beers but this is not done in order to control beer pH. It is done as a compromise for the best performance of the hundreds of enzymes that are involved not only in converting starch to sugar and breaking down protein but in the production of the many substances that contribute to the flavor and body of beer. Yes, the mash pH will have an influence on the pH achievable by the yeast. It's like any feedback based regulator. If you stress it it doesn't do as good a job as it does when presented an input consistent with the set point.

If you mash at low pH not only do you produce a dull beer but the yeast have to expend more metabolic energy in producing acid that they would had you presented them a wort at lower pH; energy that you would prefer they put into producing beer.

 

[laserghost]

In Brewing Better Beer by Gordon Strong, he recommends finished beer pH be no higher than 4.5 ... for flavor and stability reasons. Apparently yeast autolysis will raise the pH. My last batch of a hoppy red was at 4.69 two weeks into fermentation, and I added a calculated amount of 10% phosphoric acid to bring it just under 4.5 – I think the difference was subtle, but noticeable. Went from good to great.