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Thread: Wort pH

  1. #1
    Join Date
    Aug 2004
    Location
    Soldotna, AK
    Posts
    44

    Wort pH

    Does anyone know if the addition of lactic acid to the mash, can precipitate calcium ions? I add under threshold amount of lactic acid to the mash to drop pH from 5.7 to 5.45 in a pale beer. I add the acid, and at a point, the mash begins to resist change, stopping at 5.45(why?). The addition of gypsum seems to make no change to pH. I sparge with water of pH 7. Final pre-boil wort is high at 5.77. After 75 minute boil, the pH reads 5.80. Shoouldn't it drop around .3 during the boil? I know alot has to do with my water chemistry of which I'm waiting for the water report, but any speculations as to what the heck's going on?

    Thanks,
    Zach

  2. #2
    Join Date
    Nov 2002
    Location
    West Chester, PA
    Posts
    393

    Oh Boy! Watery Love.

    Hey!

    First off, you need your water analysis. Get this from your local water authority. They are required by law to provide you with it (EPA reg). If you have the $$$ and time to send it to an independent lab for analysis, good for you, but you need info right now.

    Second, the pH of your water is not important….the pH of your mash is. That being said, do get super worked up about it. The target range is 5.2-5.6 depending on who you ask and what you are trying to do, but trust me….anything up to 6.0 will convert.

    Some notes about lactic acid: lactic is an organic acid….it’s a strong organic acid, but it is still organic and hence tends to buffer in a specific pH range….guess where? Something from my old books:

    “The use of lactic acid in cases where the water is high in temporary hardness can cause the formation of calcium lactate, a powerful buffer in the pH range of 4.0 to 5.7.” Tah Dah!!!!!!!

    Couple things about your water….I can guess without even seeing your report that your water is hard, and not just hard but high in alkalinity (aka temporary hardness aka Calcium Carbonate, aka bicarbonate…..all are more or less the same BAD) by high I mean anything over 150ppm (mine is like 320ppm as Calcium Carbonate) If you use ground water its most likely hard since an awfully lot of ground water comes from lime stone aquifers. Guess what lime stone is: Calcium Carbonate.

    You can remove your temporary hardness a couple of different ways. 1) Ro (big $$$$, takes out all of the minerals…not so good unless you blend back. 2) Resin bed filtration (same as 1, but more so) 3) Boil your mash water, cool it to precipitate Calcium Carbonate as white film, rack off of the Calcium Carbonate and brew away.

    The boiling program is energy intensive, and will remove Ca, so if your water is low in permanent hardness (Perm = total – Temporary (aka alkalinity, aka Calcium Carbonate, AKA Bicarbonate) you will need to add back Ca from somewhere….might I suggest Calcium Chloride instead of Gyp. It is softer, and the suphate from gyp will make your water give harsh astringency to your beer…which you don’t need.

    I have one more suggestion. Use your water as it is and don’t change a thing! (GASP!!!!! Said the crowd). Look, water is probably your only local ingredient, and hey….I’m all about locala. if it doesn’t’ taste like ass, it’ll make good beer. It might not make good Chezk pils, but you can always treat your water for that style.

    Something else for ‘ya:

    Switch to phos in your mash if you must acidify (dogma and whatnot), use small amounts and focus on the ion content of the water you are using instead of worrying about the mash pH so much. Also, here is what’s up with your increasing pH:

    “Often improper or unnecessary acidification of the mash can increase the pH of finished beer by increasing the production of nitrogenous degradation products and phosphates which act as buffers. The age of the malt and the sulfuring conditions can also influence the pH”


    Some mind numbing stuff for you:

    Calcium: Ca
     Primary contributor to hardness of water
     Plays a critical role as an enzyme cofactor in:
     Malting
     Mashing
     Lauteing
     Boiling
     Fermentation
     Almost every step!
    The calcium ion is by far the most influential mineral in the brewing process. Calcium reacts with phosphates, forming precipitates that involve the release of hydrogen ions and in turn lowering the pH of the mash. This lowering of the pH is critical in that it provides an environment for alpha-amylase, beta-amylase, and proteolytic enzymes

    Carbonates and Bicarbonates
     Primary contributor to alkalinity (temporary hardness)
     Hinders starch gelatinization (enzymes)
     Contributes a harsh bitter flavor over 200ppm
     Can reduce fermentablility by empeding enzymes
     Causes difficulties in color, wort filtration, and Impedes trub flocculation (cold break)
    The presence of carbonate ions and their effect in raising pH can result in less fermentable worts (a higher dextrin/maltose ratio), unacceptable wort color values, difficulties in wort filtration, and less efficient separation of protein and protein-tannin elements during the hot and cold breaks.

    Cheers, and drop a note if you want more dorkery

    Larry

  3. #3
    Join Date
    Aug 2005
    Location
    Nashville, TN
    Posts
    258

    Smile wort pH

    Zach;

    As I saw on your Probrewer.com profile you are in the same town as I, Nashville, TN.
    Now, knowing our water and know what it is doing to our mashing, why do you want to use lactic acid in the mash? To lower the pH? The addition of CaSO4 in to your mash water is not directly measure with your pH meter, it will affect your enzyme work potential, AND through this, lowers the pH.
    My pH control in the mashing shows that we in N'ville (depending on additions of water minerals and beer type brewed) in the mash pH range of 5.4 - 5.7.
    As far as flavour goes, IMHO, beers treaded that way a very dry in the aftertaste.
    If you still want to lower the pH with lactic acid, please use the following calcualation:

    amount of lactic acid:
    to bring 1 liter of unboiled wort from pH of 5.54 to a pH of 5.20, 14.25 ml lactic acid stock culture solution is used.

    And, if you are still planning of using lactic acid in your beers, I recommend to use it during wort boiling, about 30 minutes before knock out. But keep in mind that through lowering the wort pH, hop resins are more isomerized.
    Otherwise, the previous post by Larry is VERY usefull and explains it too.

    If you want to discuss this in more detail, please stop by for a beer.

    Fred

  4. #4
    Join Date
    Aug 2004
    Location
    Soldotna, AK
    Posts
    44

    pH

    Thank you for the information Fred and Larry. Fred, i'm actually back up in Alaska now, just havn't changed my profile location yet. I was experiencing some new water problems I had never encountered in Nashville. Water chemistry has to be the single most confusing, yet interesting part of the whole brewing experience. I'll never fully comprehend it, but dang it, I won't stop trying to figure it out! Thanks again, and Fred, someday come to Alaska and stop by our brewpub for beer! It should be open in a year from now.


    Zach

  5. #5
    Join Date
    Oct 2002
    Location
    Tadcaster, Yorkshire, UK
    Posts
    1,075
    If you have high temporary hardness levels you might well do better to use food grade suphuric acid additions to the water until you achieve a pH of 7 at ambient. You will do better if you then degas it.

    The only problem with this of course is you may end up with very high sulphate levels, which may make the beer a little harsh or help give rise to sulphury beer if you are not careful.

    I agree with earlier comments - if you want to achieve a specific taste, get the water checked out and treat it to get the mineral salts balance you want. If you want the local taste of a totally unadulterated beer - just go for it as is.

    Have fun

    Cheers
    dick

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