Craft The Perfect Draft - Brewing Water Part 2

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This is the second installment in the Brewing Water series. The link below will direct you to part one if you wish to read it too.
Craft The Perfect Draft - Brewing Water Part 1
Today we wade a little bit deeper into what goes on in the mash and how our brewing water can influence efficiency and the fermentability of our wort.

The Benefits Of Using RO Water In Brewing
Knowing the differences between hard and soft water measured by the concentration of calcium and magnesium in your brewing water and the styles of beer that will benefit when brewed with harder or softer water gives you the opportunity to brew a more flavorful beer. Eliminating chlorine or chloramine from your brewing water will eliminate the dulling effects they have on your finished beer while improving the beer's flavor and taste even more.
Knowing the hardness of your brewing water and which style of beer tastes better when brewed with it and then filtering that brewing water through a carbon block filter are two easy ways brewers can greatly improve the quality of their beer without a whole lot of effort.
Getting the maximum benefits from all grain brewing also depends on two other very important properties of our brewing water, alkalinity and pH levels. Brewing water alkalinity is a buffer that we build into our water profile to resist changes in pH levels that happen when the acid from darker grains tries to lower the pH level or when base from the potassium released during the mash tries to raise the pH level.

High Efficiency Filters Waste Less Water
An example of how alkalinity, or buffering, maintains a specific pH range when acid is introduced can be thought of like this. "...the human body naturally maintains an internal pH range of 7.3 to 7.4 and a typical beer has a much lower pH level measuring in the 4.0 to 4.5 range but when we drink several beers our internal pH level stays within the same healthy 7.3 to 7.4 range..."
Our body has a very strong buffer, or high alkalinity level, that has been programmed to maintain the optimal 7.3 to 7.4 pH range that keeps our cells and us alive. Examples of a weak buffer or low levels of alkalinity in water are distilled, reverse osmosis [RO] and deionized [DI] water that through the distillation or filtering process have had their salts and minerals removed leaving the water with very low alkalinity and stripped of any buffering power.

Ingredients Used To Adjust Water pH And Alkalinity
Very small additions of acid will lower the pH level and very small additions of base will raise the pH level of water when it's in this state because it lacks any strong buffering needed to resist those changes.
The optimum pH range for mashing grains is between pH 5.4 to 5.6 when measured at 77F [25C]. When making brewing water pH adjustments the goal is to also build in buffering, or the alkalinity level, that is strongest within this targeted pH 5.4 to 5.6 range. The reason for buffering brewing water in this range is to counteract the rise in pH level caused by the potassium produced during the mash.

Digital pH Meter With Replaceable Electrode
Potassium is produced throughout the mash as grains soak in the hot mash water resulting in a mash pH level higher than the optimal pH range, unless the brewing water pH and alkalinity levels have been adjusted to counteract the rise. The addition of calcium to the brewing water neutralizes the rise in pH level caused by the buildup of potassium in the mash and lowers the pH level so it stays within the optimal pH 5.4 to 5.6 range.
When we talk about adjusting the pH of brewing water to target a specific pH range we also have to adjust the alkalinity of the brewing water so it's buffering is the strongest within that pH range. With low alkalinity levels and weak buffering any adjustments made to the pH of a brewing water profile will be easily changed once the water comes into contact with the grains during the mash. Temperature also has an effect on brewing water and mash pH measurements in a not so obvious way.

Mash pH Influences Wort Fermentability
While the warmer 148-158F [64-70C] mash temperatures drive off the acidic carbon dioxide which in effect raises the pH level, readings taken at the higher temperatures interfere with the response of a digital pH meter resulting in readings that average 0.2 points lower than when taken at room temperature. In order to get the most accurate pH readings the sampled liquid should always be at or a few degrees above average room temperature.
Vince "Screwy Brewer" Feminella
[email protected]

Potassium is not "produced", maybe you meant "released"?
I don't think it's the calcium that buffers mash pH, but the anions (SO4, HCO3, Cl). pH is a measure of hydronium ion concentration (H+ or H3O+)
Thanks for these articles. I've never really spent the time to learn the water science, but this makes a lot more sense now. I will be ordering a water test this week and hopefully be able to make some changes on my next batch!
Please understand the subject before writing articles on it. There are many errors here. I think maybe you were trying to discuss phosphate, not potassium.
@rmyurick @orangehero thank you for pointing that out for us. The purpose of this article is to introduce homebrewers to water properties in a way that isn't quite as intimidating as some would lead us to believe. Case in point I was able to improve the quality of all my beers using this interpretation of the underlying principles.
I don't claim to be a chemist or to have as firm a grasp on all the science behind water properties as you may. I'm just a guy who loves to brew great tasting beer and sharing his results with others. If anyone expected a scientific paper on the subject, I'm afraid I may have disappointed them as well.
Can you please private message me the corrections, or share them here, so that I may make adjustments to the article where I deem necessary?
Thank you! Nice job distilling a scientific topic into useful information for the average homebrewer.
Are you sure 5.4 to 5.6 is the optimum ph for mashing? I thought 5.2 to 5.4 was, according to the water chemistry primer here on home brew talk. I don't know anything about water chemistry, but I'm trying to get a "simple" handle on it in order to brew the best beer possible. Without becoming a chemist (who has the time?).
Simplifying a complex system such as water chemistry is great if it is done correctly. I have read several such articles and book chapters. This, I fear, is adding to the misinformation (and omissions) that the internet has become full of.
The problem that I see is that people who do not have the chemistry background will read this to be factually correct when it is not.
I do claim to be a chemist, and agree with the previous posters that the errors need to be addressed. That said, I am not volunteering to do so; there are plenty of correct articles and book chapters on the subject.
@paul_111 I found it interesting that not one of your 113 posts over the past four years have ever been on water profiles or properties. Unless you are willing to point out specific inconsistencies in this, or any other article written, I have my doubts as to just what you may or may not know about the matter.
I am glad you find my post history "interesting". You may do what you like with your doubts; I will not be drawn into an argument because I do not post as you think I should; I use this forum for information on a hobby.
While the horse is still twitching, please note that potassium and calcium have no bearing on pH, as rmyurick initially pointed out (and you thanked for correcting), but did not act on the information. Please do the HBT community a favor and make corrections where necessary to prevent future confusion.
As my post history indicates, I likely won't reply any further, as I have other things to do.
@paul_111 thank you for your comments. The article is over 2,500 words long, can you be a bit more specific on how you came away with calcium, potassium and pH?
For anyone wanting to know more about pH in brewing, you can continue your education with the 3-part article on Kai Troester site. Part 3 discusses the contribution of phosphates, calcium, etc in the buffering and resulting pH of the mash.
Here's a link to part 3, which is most relevant to the article above, but if you're new to the subject, jump back to Part 1.
Excellent suggestion, that is a great write up. You can also listen to Kai discuss PH on the March 17th and 24th 2011 episodes of Basic Brewing Radio which you can find here:
There is a link below the episodes for his PH worksheet.
Another great PH worksheet is Brun Water: