Mash pH vs. Sparge pH

Discussion in 'Recipe Editor' started by Blackmuse, Jun 30, 2020.

  1. Blackmuse

    Blackmuse Well-Known Member

    Joined:
    Jul 8, 2012
    Messages:
    523
    Likes Received:
    453
    Trophy Points:
    63
    Gender:
    Male
    Occupation:
    Electrician (Previously a 6th grade Teacher)
    Location:
    Maine
    Anyone know why the calculator states that for the mash, along with grains, minerals (calcium etc.) that adding 2ml of lactic acid will help bring me down from 6.5 to 5.4 pH BUT I only need to add .5ml (1/2ml) to my sparge water to get it from 6.5 to 5.5.....

    It doesn't seem to make any sense!
     
    AHarper likes this.
  2. Yooper

    Yooper Administrator
    Staff Member

    Joined:
    Nov 16, 2013
    Messages:
    2,280
    Likes Received:
    1,335
    Trophy Points:
    113
    Gender:
    Female
    Occupation:
    Happily retired
    Location:
    Upper Michigan/Florida
    What are the volumes you're using to calculate this? If you've got a larger volume of water in the mash than in the sparge, you'd need more acid.
     
  3. Nosybear

    Nosybear Well-Known Member

    Joined:
    Jul 16, 2012
    Messages:
    8,649
    Likes Received:
    5,576
    Trophy Points:
    113
    Location:
    Aurora, CO, USA
    Takes more acid to move the pH of the buffered mash than the unbuffered sparge water? I see this all the time in my brewing.
     
    Trialben, Yooper and Pricelessbrewing like this.
  4. Blackmuse

    Blackmuse Well-Known Member

    Joined:
    Jul 8, 2012
    Messages:
    523
    Likes Received:
    453
    Trophy Points:
    63
    Gender:
    Male
    Occupation:
    Electrician (Previously a 6th grade Teacher)
    Location:
    Maine
    It doesn't seem to matter the volume but I typically prep 4-5 gallons of sparge water and my mash water is typically in the same area (9 gallons of water total typically).
     
  5. Blackmuse

    Blackmuse Well-Known Member

    Joined:
    Jul 8, 2012
    Messages:
    523
    Likes Received:
    453
    Trophy Points:
    63
    Gender:
    Male
    Occupation:
    Electrician (Previously a 6th grade Teacher)
    Location:
    Maine
    I am glad that it is common I guess then it means I must not be doing anything wrong!...

    But doesn't it seem odd? - It takes more acid to acidify water that is already being acidified by malts and additional minerals than it does to water that has no malts or additional minerals? in
     
  6. Pricelessbrewing

    Pricelessbrewing QA Software Tester
    Staff Member

    Joined:
    Jun 8, 2016
    Messages:
    556
    Likes Received:
    301
    Trophy Points:
    63
    Gender:
    Male
    The minerals in the malt and mash act as resistance to changes in the pH. In chemistry terms it referred to as the buffering capacity of a solution.

    From wikipedia, "Buffer capacity is a quantitative measure of the resistance to change of pH of a solution containing a buffering agent with respect to a change of acid or alkali concentration"

    The greater the buffering capacity the more acid/base is needed to change the pH. It works similarly with temperature as well, a sugar solution or salt solution takes more energy to heat up than a pure water solution due to the heat capacity.
     
    Trialben likes this.
  7. Mark Farrall

    Mark Farrall Well-Known Member

    Joined:
    Oct 19, 2017
    Messages:
    1,073
    Likes Received:
    1,090
    Trophy Points:
    113
    Location:
    Melbourne Australia
    There's also the logarithmic scale coming into play (but only a little bit in your example).
     
  8. Blackmuse

    Blackmuse Well-Known Member

    Joined:
    Jul 8, 2012
    Messages:
    523
    Likes Received:
    453
    Trophy Points:
    63
    Gender:
    Male
    Occupation:
    Electrician (Previously a 6th grade Teacher)
    Location:
    Maine
    Thank you so much for this explanation!
    - You have no idea how many times I have read about water, pH and minerals and have read almost your exact words but it went right past me! It took the words with the experience for it to click I guess! It finally makes sense!
     
    Craigerrr likes this.
  9. Craigerrr

    Craigerrr Well-Known Member

    Joined:
    Mar 14, 2018
    Messages:
    3,413
    Likes Received:
    4,478
    Trophy Points:
    113
    Nothing like the moment of the epiphany!
     
    Trialben likes this.

Share This Page

arrow_white