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-   -   EZ Water Calculator 3.0 (http://www.homebrewtalk.com/f128/ez-water-calculator-3-0-a-261001/)

nilo 10-07-2011 01:26 AM

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Hello TH, thanks for all you effort on the tool.
I have started using EZ3.0 and noticed it was over predicting my PH and before I could comment on this I waited to get more data so we could (or not) make any sense of this.
I have a Milwaukee MW102 PH meter that I calibrate everytime I use. I take mash samples at 15min into the mash. Samples are used when close to 25C.
I have compiled the data for my last 13 batches, all light beers, that I started adjusting my water with EZ calculator. Last 5 batches I used EZ3.0, but I went back and calculated the predicted PH using both 2.0 and 3.0 for each recipe.
Basically, EZ3.0 is over preciting a lot. Although EZ2.0 was also over predicting, it was much closer.
I'm not sure if there is any pattern on this data, just wanted to share and see what you think.


kincade 11-11-2011 11:20 PM

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Perfect. Thanks for the information; I'm doing an APA tomorrow so I plan to try this the 'correct' way and see how things turn out.

I do have one rather dumb question still. For those of you that are using the spreadsheet, this this your one stop shop for adjusting water? Or are you using in conjuction with Palmers spreadsheet / Bruinwater / etc?

To date I have been using Palmers spreadsheet to determine ppm of CA or MG needed to adjust mash then going to the EZwatercalc spreadsheet and dividing those up between the three choices in order to keep the water balanced. If additions wouldn't cut it, then I add some lactic. But I may be adding unneccesary complexity to the process.

Here is my last water adjustment for a wheat beer for reference.


atreid 11-29-2011 10:15 PM

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Ok I just started looking into this great Spreadsheet and I entered all my tap water data, and grain bill for my next brew, an English IPA.

I added 8g of Gypsum, 1g of CaCl2, 2g of Epsom, all that to get a decent water profile, with 300ppm Sulfate and 0.16 Cl/SO4 ratio to enhance bitterness. My question is not actually about that.

Problem was my pH was 5.72... not very good... As I can buy 88% lactic acid at my LHBS (never tried that before), I added 4mL in the spreadsheet and I now have 5.46, pretty good enough...

My question is: I now have an Effective Alkalinity of -163ppm and a Residual Alkalinity of -276ppm.

What is the meaning of those negative values? I can't seem to find a clear answer anywhere...

Thank you!

EZ Sheet included right there:

Attachment 39472


ajdelange 01-31-2013 07:55 PM

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The rule of thumb is high buffering within 1 unit of a pK. Assuming that a lot of the buffering comes from phosphate (a fair assumption since there is so much of it in malt) you are safely away from the closest pK's (which is exactly why 5.2 doesn't work) but of course there are dozens of other acids in malt.

I can't tell whether the titration curves are flat or not. I've measured some that are and some that aren't but that's because I've never measured one correctly - a process I must undertake when I have some time. It is going to be a very time consuming process - perhaps not so bad when I actually get rolling.

Now if bicarbonate is involved the first pK is 6.38. At any pH above 5.38 there will be appreciable buffering from bicarbonate - the higher you go the more there will be until you hit 6.38 at which point it starts to roll off again.

The graph below shows the buffering capacity in mEq/mmol - pH (1 mmol of carbo comes from 100 mg of lime or 84 mg of sodium bicarbonate) on the left axis and the number of mEq of mL of 23 Be' HCl (concentrated) which would have to be added to a liter of water with 100 mg of lime in it to reach the pH on the bottom axis. It's pretty plain from either of these curves that the buffering is substantial in the rule of thumb region and that the titration curve (the red one) is reasonably linear in that region. When outside, however, it is highly non linear.


DSmith 02-20-2013 01:50 PM

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Quote:
Originally Posted by GUB View Post
Kai - I lighlty crushed the malt in a mortar and pestle of all things. The advice I received from this forum is that the consistency of the crush was not overly important. Someone even recommended using a coffee grinder. In other words, it was not the same consistency that I use in my brews.

As for the l/kg ratio I personally don't see a huge difference (non-scientific, in other words), as if I change my mash volume in EZwater3 from 38L to 50L (approx 2.5l/kg to 4.0l/kg) and keep my grain numbers/vol the same, the pH only rises 0.02. This says to me that water volume plays no part (well, no a significant difference). I could be understating this, happy to hear otherwise.

And for what it is worth, the example I gave in my "results" was the pale beer that was only 0.01 out (between EZ and actual)...I used the 2.5l/kg mini mash test as the basis of the mash pH calculation and actually mashed at around 4.1L/kg (12.5kg/50L water) and the results were near identical. In the future when I get a chance I could easily do a side by side in the lab.
I've modified EZ water to scale the mash to a total of 100g and report the test water needed in mL (based on the actual planned water volume/weight ratio; typically 1.5 qt/lb). The grain is ground fine in a coffee grinder and mashed for 10-15 min in mason jars at 150F-160F (pic below). The crush isn't the same but the data has correlated well to actual mashes measured at 10-15 min.

One of these mashes can be done while heating the mash water to determine if any acid will be required for brewing a beer you have no experience with.

I have individual base grain pH in distilled water for:
Crisp Maris Otter
Rahr American 2-Row
Weyermann Pilsner
Castle Pilsner
Global Malt Dark Munich (10-14L)

If there are interest in those, I'd prefer to check them all one again and post the results. The pH meter is a Hanna 98128, 2 point calibration prior to testing room temperature samples and calibration verification after the readings.

Attachment 102567


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