Does a ferulic acid rest lower mash pH?

[zwiller]

If so, how much? I assume it is just minor... Anyone know?

Many thanks in advance!

 

[ajdelange]

I think probably not. It has a carboxylic acid group with pK of 4.58 so it is well dissociated at mash pH (89% at pH 5.4) but its precursors are also carboxylic acids with pK's even lower thus it would seem that its biosynthesis would actually consume a few protons. Then there is the fact that there would be so little of it on a molar basis.

 

[dstar26t]

I'll bet if you hold the rest for 24 hours, you'd get some pH drop.

 

[ajdelange]

Yes you would but it wouldn't be from ferulic acid.

 

[zwiller]

Thanks guys. I am talking about a short 15m rest at 104F for a hefe. This stems from reviewing many well documented successful hefe recipes that do not incorporate much pH management. AJ, I assume the same applies to a rest conducted at 5.8?

 

[ajdelange]

Yes, it would.

 

[beersk]

So there'd be no problem in adding my planned amount of acid malt to the mash for a ferulic acid rest in the 104-113 range, I take it.
I wonder how the science of it was started that a ferulic acid rest didn't need pH management...

 

[zwiller]

Yeah, I think so. I took the exact same thing from AJ's comment and this also mirrors my research about it. I think the science is well documented and just came from lab testing various pH. Another interesting bit is the reaction continues for 2 hours until leveling off. Now, if you really want clove...

I have a sneaking suspicion there is some pH management in these recipes but it is not being disclosed. Maybe acid/sauergut/etc. It would have been really cool if the ferulic acid rest did actually dial in mash pH though!

 

[beersk]

It would have been really cool if the ferulic acid rest did actually dial in mash pH though!

Agreed, that would be really nice.