Author Topic: Shift in thought regarding optimal mash pH  (Read 13972 times)

Offline mabrungard

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Re: Shift in thought regarding optimal mash pH
« Reply #30 on: August 11, 2012, 06:58:29 AM »
While we're discussing pH, why is the final pH of wheaqt beer so much loer than all-barley beer in spite of both starting at a similar mash pH?

Its less a factor of the mash or wort pH and more a factor of the yeast.  Some yeast produce more acids which results in a more acidic beer.  Weizen yeast has a number of factors that are quite different from other yeasts.
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Offline nateo

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Re: Shift in thought regarding optimal mash pH
« Reply #31 on: August 11, 2012, 07:40:21 AM »
Its less a factor of the mash or wort pH and more a factor of the yeast.  Some yeast produce more acids which results in a more acidic beer.  Weizen yeast has a number of factors that are quite different from other yeasts.

I've noticed the same thing with wine yeasts. Some are dramatically more acidic than others, even when fermenting in the exact same must.
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Offline tomsawyer

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Re: Shift in thought regarding optimal mash pH
« Reply #32 on: August 13, 2012, 11:49:45 AM »
While we're discussing pH, why is the final pH of wheaqt beer so much loer than all-barley beer in spite of both starting at a similar mash pH?

Its less a factor of the mash or wort pH and more a factor of the yeast.  Some yeast produce more acids which results in a more acidic beer.  Weizen yeast has a number of factors that are quite different from other yeasts.
Interesting, do we know what organic acids are produced in greater abundance?  I suppose its citric, malic or lactic.  If it were mostly malic I could maybe do malolactic fermentation on my wheat beer like I do for red wine.  Given the description of a citric character, I would have to guess citric acid although malic has a pretty tart character as well.  Then theres the ferrulic acid possibility which is found at higher levels in wheat, but is decarboxylated by the yeast and is no longer an acid once converted.
« Last Edit: August 13, 2012, 11:55:48 AM by tomsawyer »
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Re: Shift in thought regarding optimal mash pH
« Reply #33 on: August 13, 2012, 11:57:07 AM »
Its less a factor of the mash or wort pH and more a factor of the yeast.  Some yeast produce more acids which results in a more acidic beer.  Weizen yeast has a number of factors that are quite different from other yeasts.

I've noticed the same thing with wine yeasts. Some are dramatically more acidic than others, even when fermenting in the exact same must.
I haven't heard of this before, which ones do you think produce more acid?
Lennie
Hannibal, MO

Offline nateo

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Re: Shift in thought regarding optimal mash pH
« Reply #34 on: August 13, 2012, 01:11:49 PM »
I haven't heard of this before, which ones do you think produce more acid?

In my mead fermentation trials, RC 212 lowered the pH much more than the others. The pH for Cote des Blanc was a little higher, K1V was higher still, and 71B and Premier Cuvee tied for the highest pH.
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Offline mabrungard

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Re: Shift in thought regarding optimal mash pH
« Reply #35 on: August 13, 2012, 01:45:21 PM »
At the seminar on Berliner Weisse at this summer's AHA National Convention, the presenter pointed out that the Wyeast 1007 produced a larger pH drop than other yeasts evaluated.  Obviously this result is only qualitative and not quantitative, but its a data point for your reference.
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Offline Kaiser

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Re: Shift in thought regarding optimal mash pH
« Reply #36 on: August 13, 2012, 01:46:58 PM »
To a large extent it is not the secretion of a given acid by yeast but its ability to pump protons (H+) into the surrounding beer during fermentation. This lowers the beer pH and the resulting pH gradient between beer and yeast aids the yeast's nutrient uptake.

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Offline tomsawyer

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Re: Shift in thought regarding optimal mash pH
« Reply #37 on: August 13, 2012, 02:13:13 PM »
To a large extent it is not the secretion of a given acid by yeast but its ability to pump protons (H+) into the surrounding beer during fermentation. This lowers the beer pH and the resulting pH gradient between beer and yeast aids the yeast's nutrient uptake.

Kai

Maybe but I don't think you can taste hydrogen ions at a low concentration.  Soda pop doesn't taste tart and its pH is on par with wheat beer.  If you are tasting something tart its an organic acid or its salt.  So I'm guessing theres something tart produced either by the yeast or from the wheat.  Since you don't expect a lower mash pH just from using wheat, it must be something produced during fermentation.

Now maybe its simply that the pH of wheat beer is what it is, and has nothing to do with an organic acid that is also present and giving the tartness.  It would just seem convenient to think that an organic acid at detectable levels, is also contributing to the low pH.
Lennie
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Offline tomsawyer

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Re: Shift in thought regarding optimal mash pH
« Reply #38 on: August 13, 2012, 02:15:31 PM »
At the seminar on Berliner Weisse at this summer's AHA National Convention, the presenter pointed out that the Wyeast 1007 produced a larger pH drop than other yeasts evaluated.  Obviously this result is only qualitative and not quantitative, but its a data point for your reference.
Odd, I've never thought of altbier as being acidic or at least not tart.  This may suggest that the two (pH and tartness) are not necessarily tied to one another.
Lennie
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Offline tomsawyer

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Re: Shift in thought regarding optimal mash pH
« Reply #39 on: August 13, 2012, 02:17:31 PM »
I did recently make a wheat beer with WY1056 and it was initially one of the sweetest most lovely American wheat beers I ever made.  One keg seemed to get tart after a few weeks of storage (during which time we drank the first keg) but this may have been from a minor infection.
Lennie
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Offline morticaixavier

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Re: Shift in thought regarding optimal mash pH
« Reply #40 on: August 13, 2012, 03:43:34 PM »
[...]  Soda pop doesn't taste tart and its pH is on par with wheat beer.  [...]

to be fair soda pop is packed with sugars and sweet will disguise tart just as it disguises bitter.
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Offline tomsawyer

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Re: Shift in thought regarding optimal mash pH
« Reply #41 on: August 13, 2012, 04:20:02 PM »
[...]  Soda pop doesn't taste tart and its pH is on par with wheat beer.  [...]

to be fair soda pop is packed with sugars and sweet will disguise tart just as it disguises bitter.

OK then think about how smooth a dry red wine can taste at a pH of 3.7.  Its likely gone through MLF to convert the tarter malic to less tart lactic acid.
Lennie
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Offline Kaiser

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Re: Shift in thought regarding optimal mash pH
« Reply #42 on: August 13, 2012, 06:49:49 PM »
Soda pop doesn't taste tart and its pH is on par with wheat beer.  If you are tasting something tart its an organic acid or its salt.

Tom,

I don't think wheat beer tastes tart.

Pepsi has a pH of 2.5, if I remember correctly, and that is 1.5 pH units below a normal wheat beer.

Good point about the organic acid and the tart taste. It must be something else than the low pH that causes this.

Kai

Offline tomsawyer

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Re: Shift in thought regarding optimal mash pH
« Reply #43 on: August 14, 2012, 05:19:17 AM »
I know there are commercial weizens htat are not tart, but a lot of people report a certain citric tartness in their wheat beers.  Some like it, some don't.  I've tried to minimize this with mixed results, which is why I'm interested to know the underlying causes.
Lennie
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Offline mabrungard

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Re: Shift in thought regarding optimal mash pH
« Reply #44 on: August 14, 2012, 05:28:56 AM »
Don't forget that the anion associated with the acid can have a profound effect on the perception of tartness.  Malic acid is the stuff used in those sour candies.  Phosphoric acid is one of the more neutral tasting acids.  Lactic acid is somewhere between.
Martin B
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