Bru'n Water question...

[jmitchell3]

How accurate should I expect my Bru'n Water forecast to be for my mash pH?



I have been using RO water and building it up. I have a TDS meter and the source water consistently reads between 10-12 ppm TDS.



I use a BAIB-type system, the Blichmann BrewEasy, with generally 8-10 gals of water total during the mash. I try to get north of 50ppm calcium as is recommended.



My last batch (oatmeal stout), my estimated ph from BNW was 5.45 or so with 3.6g of gypsum + 2.4g calcium chloride. Actual pH after 10 minutes in the mash was 5.23 (29.2C) which rose to 5.34 (28.1C) by 30 minutes into the mash.



It seems like I'm having more issues with darker beers being lower than expected, and lighter beers being about right or higher than expected.



I am adding lactic as needed AFTER dough-in per the instructions. (If needed / called for)

Should I expect more accuracy in the pH estimate and/or less variability in my results, or is this kind of variance normal?

 

[jjeffers09]

Nothing is as accurate as a calibrated reading. Even a pH test strip is better than guessing off of bru'n Water calculation. Given a great understanding of your malts and water chemistry, any calculation performed is dependant on the data input. How accurate is the data your are using? you see where I am going with that right? Believe me I hold Bru'n Water and the information is gives us at our fingertips in high regard. However, nothing should be taken for granted. There is a lot going on that affects the pH of your mash, and a reading is your best bet. There are a lot of homebrewers noticing the difference in golden promise missing the pH mark lately. As for the why's to that statement, it would take someone more educated than me in the subject to answer that one. I would only be hypothesizing.

 

[catalanotte]

Your observation of darker beers resulting in a lower mash pH sounds right, assuming you are using the same treatment for the water. If you are adjusting water differently for light and dark batches, and still getting this variability, its hard to say. Could be a small difference between the actual water properties and what you are entering.

Have you or anyone else seen pHs go down during the mash? I just recently bought a pH meter and started closely watching mash pH and noticed that I started the mash at 5.75 and saw it drop to 5.55 after about 30 minutes. I was predicting a 5.5 based upon the water treatment (brewersfriend.com water calculator).

 

[jmitchell3]

Your observation of darker beers resulting in a lower mash pH sounds right, assuming you are using the same treatment for the water. If you are adjusting water differently for light and dark batches, and still getting this variability, its hard to say. Could be a small difference between the actual water properties and what you are entering.

Have you or anyone else seen pHs go down during the mash? I just recently bought a pH meter and started closely watching mash pH and noticed that I started the mash at 5.75 and saw it drop to 5.55 after about 30 minutes. I was predicting a 5.5 based upon the water treatment (brewersfriend.com water calculator).

Lol, no my adjustments are not one-size-fits-all. Thats the entire point of using something like bru'n water.

And yes my measurements are with gram scale to 0.01 resolution, a pH meter calibrated before each use and stored properly in solution, reading to .01 resolution, and using as precise malt color as possible with as clean a starting water profile as possible (< 12 ppm TDS)...

 

[mabrungard]

While a room temperature reading with a freshly calibrated pH meter is best, that equipment may not be available to most brewers. I have to disagree with the contention that a pH strip reading is better than a prediction, though. pH strips are notorious for their inaccuracy in low ionic strength solutions and guess what wort is? Combine that inaccuracy with the fact that we deal with wort of varying color and you have little chance of predicting within a tenth. A brewing water pH calculation can easily be more accurate than strips.

 

[jjeffers09]

A very good point Martin, I completely agree pH strips are not ideal. I can only say I use Bru'n Water as a guide, such as bumpers on a bowling lane. But to find out how many pins I hit? I get the pH meter ready. I think we agree a pH reading is better than not. In case you get to using 'homemade' crystal malts, or toasted adjuncts, or unmalted grains. It is a good idea to get a pH reading, rather than using estimated data to input to a calculation and hoping for its accuracy. Brew on boys! Brew on!

 

[jmitchell3]

So what you all are saying is we have only a rudimentary estimate (+\- ph 0.5?) of what the mash ph will be until we get a measurement? So planning to get in the ballpark, then plan for on the fly adjustments everytime to get to where we want to be?

 

[doug293cz]

So what you all are saying is we have only a rudimentary estimate (+\- ph 0.5?) of what the mash ph will be until we get a measurement? So planning to get in the ballpark, then plan for on the fly adjustments everytime to get to where we want to be?

Usually the estimates are within 0.1 or 0.2 pH (based on lots of anecdotal reports.) Unusual malts or adjuncts can cause significantly greater errors. If you are doing something you are concerned about, rather than try to adjust on the fly during the mash, do a small test mash with the same grain bill ratios and proportionate water volumes and water treatment. Then use Bru'n Water to figure out how much acid or baking soda to add to move your mash the required delta pH. You should still check pH during the mash.

Brew on