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Chapter 6 of the Water Book and Chalk

Well, I’m already halfway through the Water Book, and I’m certainly learning a lot. The book provides clear scientific evidence that chalk (calcium carbonate) does not work effectively for increasing pH in the mash. When brewing dark beers with my water, I generally have to add chalk based on the Bru’N Water spreadsheet. The recommendations are to use calcium, sodium or potassium hyrdoxide or baking soda. So why do all the homebrew stores including our host still sell chalk for increasing mash pH and do not sell any of the ones that are effective? Are the other products too dangerous to handle and so they don’t want their employees or customers to mishandle them and get hurt? I can get food grade calcium hydroxide from ebay. Also, I’m not sure why the book didn’t go into sodium carbonate more. It only mentions it in one sentence that it would be effective. I would think this would be a safer and effective option. You’d have to watch how much sodium you end up adding to the beer though. I can also get this on ebay as food grade quality product. The second question I have is regarding the Z alkalinity equations which I’m still trying to wrap my head around. Does anyone know if the Bru’N Water spreadsheet factors this in? The book certainly makes enough references to Martin’s work. Thank you.

Thats good you can absorb all that technal info… I’m back to my second round of reading… pH changes can be a struggle if you want that to be… I haven’t had too much problem as of late, by understanding the relation of my starting water pH and after adding malt, Thats where I start… In my cache of water altering arsenal, Baking Soda, for raising pH… seldom used now. I have calcium chloride and gypsum, lactic acid and citric acid… The Z alkalinity equations eludes me now, I sure I’ll find it, BUT, I wouldn’t struggle to get your head wrapped around it to brew great beer… The higher the alkalinity the more buffering capabilities, meaning, the more it takes to change the pH… Once you get your pH altering well established, then the sulfite/chloride is where the magic takes place with your malt to hop schedule… Sneezles61


While there are a couple of mentions of Bru’n Water in the Water book, its not an endorsement. AJ DeLange and I were the technical editors for the book and that is a reason why you see some familiar references in there. The Z alkalinity concept was developed by AJ while the book was authored. I haven’t really studied his concept, but it is somewhat similar to the concept used in Bru’n Water.

Homebrew stores sell what the wholesalers have in stock. Chalk is one of those staples. Chalk needs a relatively strong acid in order to dissolve it. There is only a teeny bit of strong acid in the mash and only a teeny bit of the chalk can be dissolved to provide the pH-increasing buffering. There is more of the stronger acids in finished beer and wine and chalk does have a use in them. But, forget chalk for mashing!

While calcium and potassium hydroxides can burn if you get them into your orifices or onto wet skin, they are less likely to be a serious hazard when handled carefully. This hazard shouldn’t be a reason that they aren’t carried in the homebrew shops…its because the wholesalers don’t provide it.

I’ve finally come to the conclusion that baking soda is really the best alternative for adding alkalinity to mashing water. The amount of sodium added to ONLY the mashing water is eventually diluted by the sparging water and the net sodium content is not offensive in darker styles. In fact, you’ll see that John Palmer did a number of taste tests to prove that sodium isn’t really a problem in brewing at modest content. I find that the amount of sodium added for my typical dark beers brewed with RO water is well below the limits suggested by John. The other good thing is that baking soda is stable and doesn’t degrade like calcium or potassium hydroxides do. Baking soda is really a win-win.


Thank you, Martin, for your reply. I will give the baking soda a try.

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