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bcoutts

Mash pH

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Seeking help with my mash profile.  After heating and holding the mash (all wheat) and adding the alpha enzymes my pH is above 6.2.  I know this is the high end for alpha but the enzymes seemed to work well (no starch).  I added some citric acid to get the pH down but after adding 300g the pH had only dropped to 5.6 - still above the beta-amylase sweet spot.  I am using carbon filtered city water - any ideas of how to get the mash pH down to where the betas would be happy?  Thanks.

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You want to hit the sweet spot for the specific enzyme you are using, both for temperature, pH, and efficiency without denaturing. As the chemical reactions and breakdowns/conversions take place you will have fluctuations in your pH. It's normal to add acid at multiple times throughout a mash.

Your other enzymes might also work well over long periods of time (throughout the fermentation) and the pH will probably get into their effective range.  Keep in mind that if you drop your pH too low, when the yeast kick off you'll need to raise it up to avoid stressing/killing the yeast.

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5-10% backset/stillage.  This generally gets us close to the ballpark, with only small additions of citric being necessary to adjust our large batch volumes (2000l).  Our water is a little bit on the alkaline side and on the hard side, so it would require larger acid adjustments.

 Find a local chemical supplier and buy USP citric from them, you'll probably pay less than $2 a pound.

 

 

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Thanks so much for the advice.  We used about 5% backset and a bit of citric to get the pH right for the beta-amylase and our yield was right where we wanted.  

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Backset is our preference for adjustments. You can trigger faults in distillate judgings when adjusting with citric. high concentration mallic is a great acid to use for adjustment

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On the novazymes spec sheet I have, it suggests sulfuric acid as an adjuster. Is that an option? I seem to have some difficulty with the idea. If sulfuric is an option, I wonder about something like formic acid or oxalic both of which are also natural and poisonous, but are much easier to get and manage. Thoughts?

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Formic Acid is a carboxylic acid that can form an ester with ethanol - ethyl formate.  This might have potential flavor implications for the distillate.  Has a rummy, winey, cognac, heady aroma.

Sulfuric may have implications as well.  In the old Arroyo papers, he utilizes sulfuric acid to adjust pH for his heavy rums.  I often wondered if the reason was simple economy, inexpensive and smaller quantities needed, or if using sulfuric acid drove higher levels of ester formation during distillation, as would be characteristic of the style.   Mineral acids like sulfuric are Fischer Esterification catalysts during reflux, and can drive higher levels of ester creation during distillation.

 

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