Getting started with water chemistry

I have recently started all-grain brewing (BIAB) and am interested in how water chemistry impacts my beer. I've been using RO water with maybe a Tbsp of gypsum for a 5.5 gal batch.

I live in Phoenix, so the water is pretty hard. The city water report seems a bit sketchy for brewing purposes because:

• It's published only once a year
• Of the ion concentrations of interest to the brewer, only sodium is listed.
• For the measurements that are reported (alkalinity, total hardness, sodium, and pH) Low and High values are give with no indication of whether the values were measured in different locations, at differnt times, or what.

I thought about having my tap water tested by Ward Labs, but based on the variability above I'm not sure how useful that would be. That is, it would tell me what my tap water chemistry was on the day it was sampled, but what would it be weeks or months later? Braukaiser's recommendation of using an aquarium test kit to monitor KH and GH as a way to know whether it might be time to send off another sample to Ward makes sense, but that sounds like it would get kind of old.

I'm thinking the best approach may be to continue using RO water from my local water store and make the adjustments recommended in ajdelange's Primer. The cost is negligible and so is the hassle.

Now for a couple of questions:

1. Is all RO water esentially the same, at least as far as brewing is concerned? Or do I need to think about sending a sample of my store-bough RO water off to Ward?
2. I read somewhere that monitoring total disolved solids (TDS) is a way to make sure that RO water is good (i.e., that the membrane filter is doing its job). Is this correct?
3. In addition to the CaCl2, gypsum and sauermalz, what salts/additives am I likely to need to add if I start with RO water? I brew mainly ales, but have been thinking about giving lagering a try.

Hi Pogden,

So hopefully I can answer your questions.

1.) More or less, the largest benefit is very low hardness and alkalinity. The second is consistency, as the ion levels are reduced to such an extent that variability is neglible.
2.) TDS is one indicator, as is pH. I use both to help monitor my R/O filter effectiveness. It seems that, for me at least, the TDS rises rather sharply when the filters are ready to expire. FYI I tend to measure from a large sample when brewing, rather than from a small bit randomly pulled.
3.) I would keep some pickling lime around, or baking soda - that way when brewing darker beers, you can adjust the pH upwards... even when leaving out the aciduated malt.

AJ said in another post - Get the mash pH correct and the rest is just seasoning. You don't mention, but if you can use a calibrated pH meter or at a minimum, good pH strips.

Best of luck!

Thanks, Matt - very helpful. I'm going to by a pH meter as soon as I figure out which one I want.

You've got the right idea using RO water.

Not only do the sources (Salt River, Colorado River, and wells) vary, but so does the proportion you get to your home.

You can use a simple GH/KH titration test kit to find hardness and alkalinity.... and get a quite good approximation of the Ca and Mg.

You could try and input what you know and balance out the rest ionically, BUT -- the sodium, chloride, and sulfate swing very wildly depending on your source on any given day.

It's going to be pretty hard to pin down those flavor ions, and the variances can make a very noticeable difference. This is why RO really shines here. Not just because, say, sodium is high. But because it's probably high, but maybe very high or just medium.

You could probably get away with a dilution for a big barley wine or RIS, but for the vast majority of beers, the wild variability just isn't worth trying to guess. Even if you're using it for a dilution.

Thanks, GotPushRods, for the "local" confirmation. I suspected that the Phoenix water chemistry varies significantly over the year, making a one-time water analysis somewhat useless. Starting with RO water seems like the way to go here.

pogden said:

I'm thinking the best approach may be to continue using RO water from my local water store and make the adjustments recommended in ajdelange's Primer. The cost is negligible and so is the hassle.

Now for a couple of questions:

1. Is all RO water esentially the same, at least as far as brewing is concerned? Or do I need to think about sending a sample of my store-bough RO water off to Ward?
   
   I wouldn't send a sample, as store bought RO water is subject to the same variables such as equipment maintenance and when they change the membrane.
   
2. I read somewhere that monitoring total disolved solids (TDS) is a way to make sure that RO water is good (i.e., that the membrane filter is doing its job). Is this correct?
   
   Yes! Invest in a TDS meter to check the store bought RO
   
3. In addition to the CaCl2, gypsum and sauermalz, what salts/additives am I likely to need to add if I start with RO water? I brew mainly ales, but have been thinking about giving lagering a try.
   
   With ales, you will likely find the pH too low requiring some pickling lime as opposed to the sauermalz.
   

Click to expand...

ajdelange's primer is an excellent starting point. At some point, you may want to download the Bru'n water spreadsheet to dial in your adjustments.