Author Topic: Mash PH  (Read 1783 times)

Offline jim42

  • BeerSmith New Brewer
  • *
  • Posts: 2
Mash PH
« on: November 07, 2018, 08:49:25 AM »
I've been having trouble with the new mash ph feature.  The mash ph that the software predicts is always higher than it actually is when I measure it (actual ph is usually 0.2-0.3 lower).  What's odd is that the first couple times I used the software, it correctly predicted the mash ph.  I thought maybe my water changed so I did a test with my LaMotte kit.  It came back with slightly higher alkalinity but only by 10 ppm and slightly higher Cl but only by 5 ppm.  I work at a LHBS so I am careful to make sure the grains I enter in BeerSmith are what I actually brew with (manufacturer, lovibond, etc).  All my volumes and losses are inputted correctly.  Any tips on what I can do to get accurate mash PH predictions?  Thanks!

Offline Oginme

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 3156
  • Goats, guitars, and a home brew; Life is good!
    • Longvu LaManchas
Re: Mash PH
« Reply #1 on: November 07, 2018, 11:49:06 AM »
No pH prediction model is perfect.  If you want to waste a few days, you can jump over to HBT and read all about the different models as people argue about which one is right or wrong -- complete with many differing theories behind their stances.

My own experience shows my results to be similar to yours.  I am typically 0.2 pH units lower than what BeerSmith predicts.  In fact, it is so consistent that I can set my pH target in BeerSmith to 5.6 and reliably attain a mash pH (at end of mash) of 5.4 +/- .05 pH units.  Being a practical engineer and seeing an offset which can be predicted, I do just that -- aim for the target that I know will end up with the actual number I want.

In the end, as long as you are close to the pH range for optimal enzyme behavior, you will get adequate extraction and conversion of the starches to sugars. 
Recycle your grains, feed them to a goat!

Offline archibeckmj

  • BeerSmith Apprentice Brewer
  • **
  • Posts: 4
  • BeerSmith 2 Rocks!
Re: Mash PH
« Reply #2 on: November 12, 2018, 06:43:43 PM »
I have had the same experience.  I generally do not rely on the recommended acid additions or my pH will be 0.3 to 0.4 lower than desired.  Glad to hear I am not the only one.

Offline Warphine

  • BeerSmith New Brewer
  • *
  • Posts: 1
  • BeerSmith 2 Rocks!
Re: Mash PH
« Reply #3 on: November 12, 2018, 06:51:21 PM »
I had no idea that this was a thing for other people too! Great to know. Next time I'll add 0.2 - 0.3 as an offset.