Help! Unusual pH drop on Weissbier

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K

Kokif

Guest
Greetings!

I've been having some trouble when brewing Weissbier. Been cooking up 20 L batches of weissbier with a pH after boiling of around 5.2.
Pitching one 11.5 g pack of Fermentis WB-06 at 16°C, oxygenating for 2 minutes at 4L/min and fermenting at 20°C.
Unfortunately, I end up with a pH after fermentation of below 3.8. There are no signs of bacterial or wild yeast contamination.
What could be the reason for this unusually large pH drop and how could I control it?

Thanks to all in advance
 
Barring infection the answer is that the yeast you used put the beer at that pH because that is the pH they are happy with. Weißbier is supposed to be tart. Is this beer too much so for your taste? If not accept what you got. If so try another strain (like my favorite: 3068).
 
Barring infection the answer is that the yeast you used put the beer at that pH because that is the pH they are happy with. Weißbier is supposed to be tart. Is this beer too much so for your taste? If not accept what you got. If so try another strain (like my favorite: 3068).

Thank you for your response. It is a bit too tart for my taste.
I was wondering if adjusting the pH with phosphoric acid might be having some influence in taking the pH too low? Or perhaps oxygenation might be the problem?

Thanks again.
 
5.2 is a perfectly respectable knockout pH so I don't think that your use of phosphoric acid for pH control is a problem. It is normal for the yeast to take pH down from kettle pH by a goodly amount - in fact that is a great way to tell if your fermentation is healthy. But a drop of 1.4 is certainly greater than anything I have ever seen and strongly suggests lactobacillus infection. Have you looked at the beer under a microscope? In a wheat beer you wouldn't be able to see the turbidity lacto produces as wheat beer is already turbid.

Whenever pH is in question I always ask about pH measurements. Are you following proper procedure with respect to calibration and sample handling? Has your meter passed the stability check as described at https://www.homebrewtalk.com/forum/index.php?threads/ph-meter-calibration.302256/?
 
I have used WB-06 and it is also too tart and tangy for my taste.

The low pH in the final beer could be an yeast trait.
 
The yeast strain is the major determining factor in establishment of fermenter pH. They excrete acid until the pH is one at which they do best and when that pH is reached stop and turn to other tasks (making beer). The fact that two of you have the same effect when using this strain and that it has a reputation for producing excessively tart beers strongly suggest that this is OP's 'problem'. Use of another strain that doesn't want pH that low should solve it.
 
I measured pH from one batch splitted into WLP380, WB-06 and MJ M-20. WB-06 pulled it down most. I think I measured 3.9.
 
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