Tuesday, December 21, 2010

Brewing Water Chemistry

Unless you're using water that was deionized by distillation or reverse osmosis (RO) you'll need to start with your local water analysis report. You county or water district should produce one annually. My report is available online, but depending where you live you may need to write or call to request one. Make sure to get the water analysis report, not the water quality report which contains mostly pictures and PR. Among other things this report should spell out the calcium, magnesium, sodium, sulfate and bicarbonate in your water as parts per million (ppm).

John Palmer has a good section or how to read your water report. Good news if you live in an area with soft water, you will have control over the mineral levels in your brewing water. If your water is hard, dilution with distilled or RO water may be required. Now you only have to figure out how much of what to add to your water to get from where you are to where you want to be. In order to adjust the ion levels in your water, the minimum you'll probably need are food-grade gypsum, measuring spoons or a scale that measures in grams and a way to calculate the various ion levels. The old-school triple beam scales are expensive, but you can get the digital version for about twenty bucks.

When trying to figure things out, I was frustrated by seeing "CaSO4" in one place, "Calcium Sulfate" in another and "Gypsum" somewhere else. Turns out they're all the same thing. Depending on your water and what you're trying to accomplish you may need all the items in the water chemistry set:

Water Salts and Their Ions [1]
Household Name Scientific Name Formula Weight
Chalk Calcium Carbonate CaCO3 40% Ca 60% CO3
Calcium Chloride Calcium Chloride CaCl2 27% Ca 48% Cl2
Gypsum Calcium Sulfate CaSO4 23% Ca 56% SO4
Epsom Salts Magnesium Sulfate MgSO4 10% Mg 39% SO4
Table Salt* Sodium Chloride NaCl 40% Na 60% Cl
*The table salt should be non-iodized. The salt you use could also be sea salt, rock salt, canning salt or kosher salt so long as it's not iodized. Gypsum and chalk should be food grade.

The weights in the table above are important because the ions you add for water treatment can only be added in pairs. You can't just add one type of ion to the water at time... much as I would like to. In order to add Soduim (Na) you will also have to add Chloride (Cl) when you use table salt. Gypsum will give you Sulfate as SO4 and Calcium (Ca), so if your Calcium is too high and your Sulfate is still too low you may also need to use Epsom Salts to bump up the Sulfate without increasing Calcium. But then you have to worry about your Magnesium level. This can make the calculations somewhat complex.

Some homebrew software will help you with the calculations. If yours doesn't there are plenty of free download-able and online tools, or you may find that you like one of the freebies better. I like the spreadsheets available from EZWaterCalculator and John Palmer. Both Palmer and EZWater have US and Metric versions, but you'll need to scroll to the bottom of the page and look for the tiny links on the Palmer site. Watch out on the Palmer spreadsheets. He hasn't protected the cells, so you can easily wipe out a vital calculation.
One real advantage for EZWater is the availability of some third-party videos that show you how to use the tool:
Brew Water Chem - Part 1
Brew Water Chem - Part 2
Brew Water Chem - Part 3
Skip the first four minutes if the first video (intro and how to order water analysis) unless you couldn't get a report locally.

You can also find several online tools. I prefer the Brewing Water Chemistry Calculator from Brewer's Friend, but you can also find calculators at Power's Brewery, ProBrewer, and Brewer' s Lair. Brewer’s Friend is nice because it warns about minimum and maximum levels for each ion, and reports how the ion concentrations impact the flavor. Based on on of the replies, I took a look at Bru'n Water and it looks very promising. I haven't had time to do anything more than download it and open it up (it's an Excel spreadsheet) but it appears to be very thorough, and covers more aspects of brewing water chemistry than any other single tool.

The Quickie Water Chemistry Primer is handy for understanding some of the issues involved, regardless of what tools you use. And John Palmer has some great information, including the only place I've been able to find a conversion chart between grams and teaspoons for everything you might want to add. My parting advice is don't worry if you can't match a water profile exactly; and if you're going to be off, undershoot rather than overshoot.


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[1] Ray Daniels, Designing Great Beers, 1996

4 comments:

  1. Good job, Bob!
    It should be noted that calcium chloride is CaCl2, not CaCl.

    Also, the weight percentages for each don't necessarily add up to 100% because for some of them, there is water of hydration included, which takes up some weight but obviously doesn't add any ions.

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  2. Thanks! That's the kind of typo that is hard to catch. It's right in the 'weight' section but not in 'formula.' Fixing it now...

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  3. Nice article. Speaking of calculators, have you seen the one that Martin Brungard created? It's well done.

    https://sites.google.com/site/brunwater/

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  4. Thanks! Looks like I need to dig into that!

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