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Water, Water Everywhere

… but what to do with it?

I spend a fair amount of time trolling the Northern Brewer forums, and one of the more frequent exchanges goes something like:

Q: OK, I have my water report, now what do I do with it?

A: Read chapter 15 of How to Brew and come back if you have more questions.

Which is technically a good answer, but even I occasionally get tired of being a dick. So, step by step, how to brew… water.

1. Get your water report. This might be available from your municipality, but since they likely average several samples from different locations, their data may not be accurate for your brewery. Your best option is to call Ward Labs, order the W-6 test, and mail in a sample. Either way, the ion concentrations you want to make note of are calcium (Ca2+), magnesium (Mg2+), sodium (Na+), sulfate (SO42-), chloride (Cl-), and either bicarbonate (HCO3-) or the alkalinity as CaCO3. These will be in ppm or mg/L, which for our purposes are equivalent.

2. Use Palmer’s nomograph to find the base-malt pH of your mash. The idea here is that the more alkaline your water is (the higher the carbonates), the more dark roasted grains will be needed to bring it down to the desired mash pH of about 5.6 at room temperature, or 5.2 at mash temperature. For example, my tap water profile is:

Ca2+: 96 ppm
Mg2+: 32 ppm
Na+: 29 ppm
SO42-: 39 ppm
Cl-: 57 ppm
HCO3-: 294 ppm

which is very hard, but not unusual for the Midwest. Plugging those numbers into the nomograph gives a base-malt pH of 5.95, corresponding to a beer color of 18-23 SRM. Essentially, my water can be used to brew only stouts and very dark porters without modification.

3. Adjust the bicarbonate to match the beer. This will require either diluting your water with distilled or reverse osmosis water (to make a lighter beer), or adding carbonates (to make a darker beer). For an example, I’m going to use the amber ale recipe from Good Beer, Easy Beer. This beer has a color of 13 SRM, so I’ll need to dilute my water. Mixing it 50/50 with distilled water more or less halves all the ion concentrations (to 48, 16, 14, 20, 28, and 147 ppm respectively), which brings the base-malt pH down to 5.83. The corresponding SRM range is 11-16, which is pretty much ideal. If you have soft water and need to add carbonates, the sliders on the nomograph page will let you figure out how much chalk (CaCO3) is needed.

4. Check the chloride and sulfate levels. Generally, sulfates highlight the bitterness and flavor of hops while chlorides accentuate malty flavors. 50 ppm is a good starting point, but you may want to go to 150 ppm or more. Unless your goal is extremely malty or bitter, though, I would try to keep the levels of both ions above about 20 ppm, in order to ensure the beer is flavorful and balanced. In the case of this amber ale, I want the hop bitterness to slightly outweigh the malt flavors, so I’m going to target about 100 ppm SO42-, and 50 ppm Cl-. In the case of very bitter beers the sulfates can be even higher, although I personally find that above about 250 ppm the bitterness can be excessively harsh. For this recipe, adding 0.75 grams of epsom salt (MgSO4) and 0.15 grams of calcium chloride (CaCl2) per gallon brings the concentrations to 99 and 48 ppm, respectively.

5. Ensure you have adequate calcium. Calcium is important for yeast health, so you want to keep the level above 50 ppm. Adding chalk, gypsum, or calcium chloride may already have done this; if not then you can add small amounts. Note though that calcium reduces the mash pH; if the effect becomes excessive you may need to add more carbonates, or dilute your base water by less. This is the principal reason that epsom salt (MgSO4), table salt (NaCl), and baking soda (NaHCO3) are sometimes used in brewing: they can increase sulfate, chloride, or bicarbonate, respectively, without adding calcium.

That’s all there is to it. The final water profile for the amber ale is given below. Play around with the nomograph tool a bit, trying to balance all the ions for a few different styles, and I think you’ll find that it becomes second nature pretty quickly. If you have any questions, though, feel free to Contact Me.

Ca2+: 59 ppm
Mg2+: 36 ppm
Na+: 14 ppm
SO42-: 99 ppm
Cl-: 48 ppm
HCO3-: 147 ppm

5 comments to Water, Water Everywhere

  • [...] wrote this about a year ago, trying to come up with a decent, short, introduction to water chemistry for [...]

  • Thanks for helping me with the beer chemistry. I’ve been trying to figure out the beersmith water profile section on my own. I’ll take your advise and start playing with the nomograph.

    Just curious, what do you think of all those alkaline water ionizers that are for sale now? I had a friend buy one for 4K but I can’t find the science behind them.

    • Man, I had to google “alkaline water ionizers”. Looks like all they do is electrolytically split the water into acid and base fractions. It might be a nice toy to have for tweaking pH, but for that kind of money I’d stick with straight acid additions. Unless your alkalinity is off the charts to begin with you’d have to add a ton of water to overcome the buffers in the mash, versus a few milliliters of acid or grams of brewing salts.

  • Saturday 10-29-11 is my first attempt at a lager, I’m not sure what to add to my water to brew a light Pilsner/Munich Helles. Any help would be appreciated.

    I have a HERM system and a Ranco controlled refrigerator to lager. I usually brew 12 gallons so I can end up with 2 five gallon kegs.

    The water report is as follows: 8.1 pH
    Calcium: 65 ppm
    Magnesium: 26 ppm
    Sodium: 93 ppm
    Sulfate: 220 ppm published 169
    Chloride: 97 ppm
    Bicarbonate: 135
    Hardness: 16 grains per gallon or 230 mg/l
    Alkalinity 13.4

    I’ve purchased 12.5 gal of distilled water to cut my water but I am a little confused as to how much to use and how much minerals to add.

    My basic recipe is: 16.00 lb Pilsner (2 Row) Ger (2.0 SRM) Grain 71.11 %
    4.00 lb Munich Malt (9.0 SRM) Grain 17.78 %
    1.50 lb Pale Malt (6 Row) US (2.0 SRM) Grain 6.67 %
    1.00 lb Cara-Pils/Dextrine (2.0 SRM) Grain 4.44 %
    1.00 oz Tettnang [4.50 %] (60 min) Hops 6.9 IBU
    1.00 oz Hallertauer [4.80 %] (60 min) Hops 7.3 IBU
    1.00 oz Tettnang [4.50 %] (20 min) Hops 4.2 IBU
    1.00 oz Hallertauer [4.80 %] (20 min) Hops 4.4 IBU
    2.00 oz Saaz [4.00 %] (0 min)
    2 Pkgs Southern German Lager (White Labs #WLP838) The starter is ready.

    • Jim,

      Obviously I didn’t get to this in time, but maybe answering will be helpful anyway.

      Your water does have enough alkalinity (RA ~50) that you might have pH issues with a light lager grist anyway, but in my opinion the bigger issue is going to be the sulfate level. For a Helles-style beer I’m assuming you want to go for a malty finish, so I’d try to get the SO4 to <50 ppm. So right off the bat you'll be diluting at least 4:1 with the distilled water. If you do that and then add 0.5 g/gal of CaCl2, you end up with ~50 ppm Ca and ~80 ppm Cl, with an RA of -15. I think that would be as good a starting point as any.


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