For most brewers (especially new brewers), rebrewing a beer many times to figure out what they should be doing for their brewing water is out of the question.
A visitor to New York stops a native and asks "How do I get to Carnegie Hall?". The native answers "Practice, practice, practice!"
Unfortunately or perhaps fortunately, the only way to make very good beer is to brew, brew, brew. Brewing is cooking. You can no more expect to make a great beer by reading a book or two and then throwing some grain into your mash tun than you can expect to make a great Bearnaise sauce by watching Julia Childs do it on television and then separating some eggs. Brewing is art, what makes art art is nuance and nuance only comes with repeated refinement.
Getting the water right requires 2 things: first, getting the mash pH under control and second getting the right levels of what I call the 'stylistic ions', those that primarily effect the flavors, into line with the style requires.
Fortunately decent pH meters are now available at moderate cost. With one of those in hand it is easy to check that mash pH is where it ought to be. A brewer can go to the Primer, a spreadsheet or calculator and get guidance as to how to prepare water, make a test mash, check the pH and correct acid or base additions as necessary. Or he can check mash pH on brew day and make corrections in the mash tun.
That is exactly the reason that Bru'n Water was created.
Bru'n Water and the other spreadsheets and caclulators are fine tools for determining a starting point and especially for learning but a brewer is well advised to check mash pH as these all are based on models and all models have limitations.
The great research that Kai Troester performed with correlating malt acidity to grain type and color made that software possible.
The last thing I want to do here is appear to be criticizing Kai's work because it represents a great contribution to the homebrewing literature but anyone using it should be aware of a few things:
He used an inexpensive pH meter without ATC - one that requires manual setting of temperature through an analogue potentiometer.
He did titrations with hydrochloric acid from the hardware store and lye bought from a home brew supplier. HCl escapes from hydrochloric acid which is why hydrochloric acid isn't used for titrations (and why you need to stand back when you open a container of it). Sulfuric acid would have been a better choice and even it needs to be standardized. Lye picks up carbon dioxide from the air readily and must be frequently standardized (against standardized sulfuric,or some other, acid).
While he worked with an impressive number of malt types he did not process multiple samples of the same malt from the same maltster. I know from my own brewing logs that there can be a lot of variation.
Again, I want to make it clear that I am not trying to be critical of Kai. He did great work. One just needs to be careful about the conclusions drawn from it.
And even though there are some that deny there is any consistent correlation between malt type or their color and their acidity,...
That would be me and the denial is based on
1. My own brewing experiences
2. Kai's data.
3. Kai's recognition of the shortcomings.
He is well aware, as a good investigator should be (and that's why you can't fault him here). He doesn't publish Pearson's r for most of the fits (which is too bad) but for the one he does it is about 0.7. That's not bad but it is not good either. I wouldn't bet a lot of money on a correlation that weak.
[/QUOTE]..my experience and that of thousands of other brewers suggests that you can rely on a fairly consistent correlation.[/QUOTE]
That's the thing about weak correlations. You can rely on them most of the time but not always. T = 14.84 + 9.827*month (Jan = 1, Feb =2...) is a model of the average temperature in DC. And that's a pretty good model. In January the average is 24.7 °F, in Feb 34.6. That's seems right most of the time. Yesterday the average at my house was 52.4.
What I have found is that there are some maltsters (Rahr) that do purposely acidify their base malt to fit their customer's needs.
Well Rahr doesn't fit the model then. Can the model be improved to incorporate it? Sure. But until that is done the model has a known limitation. And I know that when I plugged data from my brewing logs into the model the results were off by .1 - .3 (IIRC - and the model was always low). Thus my brewing practices somehow represent another limitation.
The other malts seem to follow Kai's findings relatively well.
A quick fix is to caveat liberally (as some of the spreadsheets do) so that the user is aware of the limitations.
So having a tool like Bru'n Water that can assess a grain bill and compare it to the brewing water and give the brewer a decent sense of where their mash pH is going to end up is very important. I know when I brew a new recipe, I don't relish the thought that I could be missing the mark badly on mash pH if I didn't have a decent predictive tool and would have to suffer through 5 gallons of less than enjoyable beer.
You don't have to do that. Use Bru'n water or whatever tool you like and then check pH. I wouldn't risk a day's labor based on the predictions of any spreadsheet (including my own) when it is so simple to check.
For those of you that brew much larger batches (like a craft brew pub) where there is potentially a lot of money on the line, brewing a fair or poor batch of beer is not an option. (I recognize that anyone making that sort of investment in a batch of beer should have and use a pH meter, but sadly some brewers don't)
The craft brewer has the opportunity to brew, brew, brew and thus incrementally discover the proper water treatment, grist bill, hops charge... which gets him the most saleable beer. If he is riding highly variable water or highly variable materials he has potential trouble. My favorite local was taught by a man who published a paper entitled "pH, pHooey! and Bill brews according to what he was taught. I even gave him a meter at one point. At the other end of the spectrum Chico Brewing does a complete water analysis every day.
Bru'n Water includes some nice features that do make it possible to predict their acid additions pretty darn closely which is an important step up from the trial and error method.
Yes it does but I wouldn't rely on it completely. Why take a chance when it so easy to check pH?
As anyone who has experimented with acids knows, you end up adding more and more acid and the pH does little and then you add another drop and the pH goes through the floor.
I've had that happen in titrations to end points well below the lowest pK but I've never had it happen in a mash.
Having a good predictive acid addition tool is VERY important to most brewers.
I strongly advise that anyone relying on an acid addition recommended by a spreadsheet or calculator (including my own) dilute that addition in a convenient volume of water and add 1/3, check pH, add the second third etc. As noted earlier in this thread phosphoric acid becomes super acid if enough calcium is present. In acidifying to pH 5.2 a molecule of phosphoric acid delivers 1 proton if the calcium level is low. If there is enough calcium present to precipitate that moelcule it deliver 3-1/3. I'm not aware that any of the spreadsheets or calculators (again except mine) takes this into account but I could be wrong about that.
As you learn about your brewing water, most brewers find that they no longer need that tool. You just know from experience what the right amount of acid per gallon or liter is.
You will have a sense but you should still check pH as variation in materials can still cause pH variances of 0.1 or more. If you are a commercial brewer buying by the rail car and who treats his water to a standard set of parmeters then you don't need to check pH except when new lots of malt come in. OTOH perhaps 0.1 is less that one needs to worry about. I guess that's a philosophical question.
For those of you starting out in brewing or with a new water source, you're going to want that tool.
I agree. As long as the limitations are honored, preferably by measurement.
Someone with 20 plus years of brewing, an endless supply of RO water, and a tendency to brew a narrow range of beer styles should probably step back and recognize that there are other ways to achieve good brewing results.
Guess that means me again. I do. But by the same token those that promulgate the use of spreadsheets and calculators need to recognize their shortcomings and in particular as they apply to lager brewers who use RO because more and more people are reaping the benefits of doing their lagers that way.
Unfortunately, not all brewers find that incorporating large quantities of RO or distilled water into their brewing regime is either practical, convenient, or cost-effective for their brewing.
Fortunately, more and more stores are carrying RO water and RO systems are becoming cheaper and cheaper. Some people have nasty water. Temporary hardness can be eliminated easily enough but there is no way to remove sulfate (for example) other than RO (except ion exchange and you would want to do RO before that).
