Calculating Kettle Salts

Discussion in 'Homebrewing' started by HOPTOMIC_BOMB, May 11, 2021.

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  1. HOPTOMIC_BOMB

    HOPTOMIC_BOMB Savant (1,044) Feb 18, 2014 California
    Trader

    Hey all quick question,

    when calculating kettle salt ppms for flavor do I use the volume that i start the boil with or the final volume post boil?
     
  2. VikeMan

    VikeMan Grand Pooh-Bah (3,067) Jul 12, 2009 Pennsylvania
    Pooh-Bah

    Using the post boil volume would be technically accurate in terms of finished ppm.

    But using the starting volume is what software does and what most people mean when they give a ppm value.
     
  3. HOPTOMIC_BOMB

    HOPTOMIC_BOMB Savant (1,044) Feb 18, 2014 California
    Trader

    So If I’m using table salt to increase malt character it’d better to use the starting boil volume then?
     
  4. VikeMan

    VikeMan Grand Pooh-Bah (3,067) Jul 12, 2009 Pennsylvania
    Pooh-Bah

    Yes, assuming you're looking for a result close to what people are talking about when they share recommended ion levels.
     
    Merlyn likes this.
  5. HOPTOMIC_BOMB

    HOPTOMIC_BOMB Savant (1,044) Feb 18, 2014 California
    Trader

    Thank you, So i guess my next question would be would I need to add less of whatever salt since the final product would be concentrated? Like if say 3g of Na in 5 gals at the start of the boil was 30 ppm would it end up being even more in the final product?
     
  6. VikeMan

    VikeMan Grand Pooh-Bah (3,067) Jul 12, 2009 Pennsylvania
    Pooh-Bah

    3 g of Na (or anything) in 5 gallons would be about 159 ppm, but I think I know what you're asking.

    Yes, if it's 159 ppm before the boil, it's going to be something higher than 159 ppm after the boil. The exact ppm would depend on how much you boil off. Let's say you start with 5 gallons of wort with 159 ppm chloride and boil it down to 4 gallons:

    159 ppm x (5 gallons / 4 gallons) = ~199 ppm

    But that doesn't mean you need to use less, unless you are targeting a specific ppm in the finished product. Again, when someone recommends, say, 100 ppm (or whatever) chloride for a sweet stout, they almost always mean the original concentration in the water, i.e. the water profile.

    Just as an aside in case there are any pedantic chemists or engineers reading...
    1 ppm <> 1 mg/L
    But it's close enough at the concentrations we're talking about.
     
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  7. HOPTOMIC_BOMB

    HOPTOMIC_BOMB Savant (1,044) Feb 18, 2014 California
    Trader

    Okay gotcha, now I understand better. Thanks for your help!
     
    Merlyn likes this.
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