Brun water issue - low ph

[matzou]

Hello everyone,

I'am a bit surprised by the estimation of the spreadsheet for a simple smash brew.

I'am doing small 10L biab full volume batch using bottled water.
(Ca ppm) (Mg ppm) (Na ppm) (Cl ppm) (SO4 ppm)
35,7 16,5 8,3 18,8 3,7 165hco3


Ez water prediction: 5.15
Brewers friends: 5.17
Brunwater: 5.4 !

The grist is 2,2kg of weyermann pilsner malt for 17,50L
The acid/mineral additions were the following:

• 5,3ml of 80% Lactic acid
• 1,1gr of gypsum
• 6,9ml of 33% calcium chloride solution

First time I Am using the ez water spreadsheet and saw a "dist water ph" for grains, I was assuming it could explain the difference and both software using different values. but then again checking brewer friends they are just using the color of the grist as info.

And yes I didn't check the ph during brewday but was as I'am always relying on Brun which has been spot on before.

If anyone has any idea as why the discrepancy ?

Thanks

EDIT:
Double checked the 2 last recipes with EZ water to compare with Brunwater and they are both 0,01 or spot on accurate.
Only the last one with pilsner is odd...

 

[Big Monk]

Hello everyone,

I'am a bit surprised by the estimation of the spreadsheet for a simple smash brew.

I'am doing small 10L biab full volume batch using bottled water.
(Ca ppm) (Mg ppm) (Na ppm) (Cl ppm) (SO4 ppm)
35,7 16,5 8,3 18,8 3,7 165hco3


Ez water prediction: 5.15
Brewers friends: 5.17
Brunwater: 5.4 !

The grist is 2,2kg of weyermann pilsner malt for 17,50L
First time I Am using the ez water spreadsheet and saw a "dist water ph" for grains, I was assuming it could explain the difference and both software using different values. but then again checking brewer friends they are just using the color of the grist as info.

And yes I didn't check the ph during brewday but was as I'am always relying on Brun which has been spot on before.

If anyone has any idea as why the discrepancy ?

Thanks

Given the grist, I’d say BW is closest. Did you use any acid? Your actual was probably a little higher than the BW prediction.

 

[matzou]

Hi,

Sorry about that I edited the post, the acid/mineral additions were the following:

5,3ml of 80% Lactic acid
1,1gr of gypsum
6,9ml of 33% calcium chloride solution

EDIT:
Double checked the 2 last recipes with EZ water to compare with Brunwater and they are both 0,01 or spot on accurate.
Only the last one with pilsner is odd...

 

[ajdelange]

None of them are 'spot on' (0.01 pH) accurate. If you get a mash pH prediction of 5.42 from a spreadsheet and measure 5.42 then you are the victim of confirmation bias. The probable chain of events is that you stick the probe in the mash sample, watch until it hits 5.42 say to yourself at this point "wow - spot-on" and remove the probe. Were you to wait longer the readings would drift to some other value.

The algorithms used in the spreadsheets are not good enough nor is the data fed to them good enough to produce errors this small. If you carefully measure the parameters of each malt in the laboratory and then combine those in the proper fashion with accurate data about the alkalinity (if any) of the water used and make a lucky guess about how the calcium reacts it is possible to produce a laboratory mash which measures approaching the asymptote within 0.01 or 0.02 of the predicted mash pH. In the brewhouse using one or any of the popular spreadsheets it isn't. Most of the time expect pH predictions to be within ±0.15 or so. Sometimes they will be off by more than that. Learn about how to use your pH meter (see the Sticky here) such that you aren't lead down the garden path by confimation bias.

 

[matzou]

Most of the time expect pH predictions to be within ±0.15 or so. Sometimes they will be off by more than that

Thanks.
So I'll therefore take into consideration that everything is a "guestimate" and just check more often if I do care about pH.

 

[mabrungard]

Anyone who thinks a program can predict mashing pH to within a tenth of a unit, is kidding themselves. There are too many variables in play! Grains, water, minerals, and acids have variability and inconsistency. Obtaining a measured result that is within a hundreth of a prediction is largely luck. However, with materials that have proven themselves reasonably consistent and which conform to their assumptions, producing a measured result within about a tenth is at least likely with some algorithms.

There is no substitute for following all predictions with a measurement by a calibrated method. For those that are satisfied without that confirmation, they can likely rest assured that their true result is closer to their ideal than if they had done nothing.

 

[matzou]

There is no substitute for following all predictions with a measurement by a calibrated method. For those that are satisfied without that confirmation, they can likely rest assured that their true result is closer to their ideal than if they had done nothing.

Thanks, sounds good to me