Wasn't there a big discussion a few years ago in the Brew Science forum on the issue of some software showing inaccurate swings in mash pH with changes in the water to grist ratio? I thought that was all hashed out and resolved a long time ago.
Wasn't there a big discussion a few years ago in the Brew Science forum on the issue of some software showing inaccurate swings in mash pH with changes in the water to grist ratio? I thought that was all hashed out and resolved a long time ago.
Something that I have wondered...which I think is in line with @thomer's original post about getting started with water adjusments...is there a simple "first steps" water chemistry strategy for somebody using RO that is maybe a step above the "add a teaspoon of calcium chloride...and maybe a few oz of acidulated malt" type advice?
There is the post from AJ on this forum: A Brewing Water Chemistry Primer
There is this blog post that I see recommended often: Water Chemistry – How to Build Your Water – Bertus Brewery
As somebody with a few years experience adjusting water starting with my tap water, I don't have a great feel for adjusting RO/Distilled water. My gut says that I would not follow or recommend either of those "simple" approaches. The recommendations above by John Palmer from the Anvil Foundry manual seem a little better (maybe).
I believe that Mash Made Easy has a "Distilled or RO Water Mineralization Assistant" that seems pretty useful. I don't use it myself just because I start with my own tap water. It has that typical hurdle that seems common with software that profiles are names like "Hoppy, Medium" so new brewers are left to figure out what profile fits their Saison, Pumpkin Ale, Baltic Porter, or Irish Stout. pH adjustment are left up to the brewer to figure out on different tabs. Most other software has the same or steeper learning curve.
I have always felt like it should be easier for a new brewer that is using RO water and brewing a 5 gallon batch of Czech Pils/Belgian Dubbel/German Wheat/Dark Mild/etc. to look up a recommendation for salt additions and pH adjustments.
This is exactly what I am seeing.I just fired up BrunWater 1.25. I put in a grist of 10 lbs of 3L base malt.
Here are the predicted pH values for some different conditions. Is this what you see @TestTickle ?
Water profile of all 0s, no additions:
Mash with 7.5 gallons of water (3qt/lb) the pH = 5.71. Mash with 5 gallons of water (2 qt/lb) the pH = 5.68. Mash with 2.5 gallons (1 qt/lb) the pH = 5.61.
So the predicted changes are fairly small until you get to thick mashes.
With 1g gypsum and 0.5 g CaCl2/gallon the changes are as follows:
3qt/lb pH = 5.18
2qt/lb pH = 5.33
1qt/lb pH =5.43
This trend would be expected as described in @Silver_Is_Money 's post #30 above. How close these predictions are to real measured values for different brands of 2-row I don't know.
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When I first started measuring mash pH I did a timecourse and noticed the change over time. Now I measure at the end because it is consistent (i.e. no longer changing, so I'm not going to catch it at a intermediate pH) and is representative of the mash pH once everything is dissolved/hydrated/at equilibrium (is there a more correct term for this?).
Does anyone know if the timecourse of the mash pH change is related to the water to grist ratio?
This is exactly what I am seeing.
Thanks to everyone for your input. @marc1 I have also just used BrunWater as an experiment. I think I have found my way around it using your references and got the same figures as you, so I know I am on the right track. I will also now experiment with Mash Made Easy @Silver_Is_Money .I just fired up BrunWater 1.25. I put in a grist of 10 lbs of 3L base malt.
Here are the predicted pH values for some different conditions. Is this what you see @TestTickle ?
Water profile of all 0s, no additions:
Mash with 7.5 gallons of water (3qt/lb) the pH = 5.71. Mash with 5 gallons of water (2 qt/lb) the pH = 5.68. Mash with 2.5 gallons (1 qt/lb) the pH = 5.61.
So the predicted changes are fairly small until you get to thick mashes.
With 1g gypsum and 0.5 g CaCl2/gallon the changes are as follows:
3qt/lb pH = 5.18
2qt/lb pH = 5.33
1qt/lb pH =5.43
This trend would be expected as described in @Silver_Is_Money 's post #30 above. How close these predictions are to real measured values for different brands of 2-row I don't know.
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When I first started measuring mash pH I did a timecourse and noticed the change over time. Now I measure at the end because it is consistent (i.e. no longer changing, so I'm not going to catch it at a intermediate pH) and is representative of the mash pH once everything is dissolved/hydrated/at equilibrium (is there a more correct term for this?).
Does anyone know if the timecourse of the mash pH change is related to the water to grist ratio?
Hopefully I may be able to achieve just that and share it.I have always felt like it should be easier for a new brewer that is using RO water and brewing a 5 gallon batch of Czech Pils/Belgian Dubbel/German Wheat/Dark Mild/etc. to look up a recommendation for salt additions and pH adjustments.
OK - we're all on the same page now!
In this software, the mineralized water differences are trending as expected, and the RO water doesn't change much until thick mashes. Since real life use generally shouldn't use RO only, then it doesn't seem to be a big problem for practical applications.
Like all software, it's for getting an estimate of mash pH, and can't know the differences between malts that aren't part of its calculations (for BrunWater these are things like: different maltsters, lots, varieties of barley, etc.). It uses broad grain type and color values to make its estimates, along with water information. If you find that it is helpful in planning mineral and acid additions overall, then it serves your purposes.
No apology necessary. All the information provided/discussed so far has been very useful as I am purely RO or distilled at the moment.I know we are getting way more into this topic than we should on this thread, so I apologize to the OP.
I do understand that software only provides an estimate based off of the SRM of the grain used. I'm not personally too concerned with any of this since I don't completely rely on estimates but rather use them as a starting point. I am just trying to make sense of what seems to be odd (to me) predictions when using 100% RO or distilled water and adding minerals.
You and I obviously have seen the same results in estimates using strictly RO. I should note that I mostly brew with tap water (well water through a carbon filter), but for more delicate styles I will often dilute with distilled (~50/50). There have only been a couple of times I have ever brewed with 100% RO or distilled, which was when I first noticed the results you posted above.
So, with 100% RO water (as you noted above and as I have also seen):
Now, let's consider the exact same grain bill and target water profile using tap water:
- With no minerals added, pH goes up as the water to grain ratio goes up. I expect this.
- With minerals added, pH goes down as the water to grain ratio goes up. This I did not expect based on my experiences with tap water.
So basically, the RO water with minerals added and the tap water with minerals added along with an identical grain bill in both mashes, based on these calculators, SHOULD (in my simple mind) have a very similar mash profile. I know that it's more complicated than that, and again, I'm no chemist...anything past basic water adjustments and pH is over my head.
- With no minerals added, pH goes up as the water to grain ratio goes up. I expect this.
- With minerals added, pH goes up as the water to grain ratio goes up. I expect this.
This doesn't affect my brew day at all, since I mostly achieve the end result that I am expecting with regards to water profiles, mash pH and finished product. I am mostly just curious to know if what I am seeing is correct since it doesn't make sense to me. If it is correct, that is fine...I at least know that the software is doing what it's supposed to do if i ever do need to go with 100% RO. If it's not correct, then I can make adjustments if needed, although it doesn't appear to be enough of a discrepancy to worry about in most cases.
I know we are getting way more into this topic than we should on this thread, so I apologize to the OP.
Aha....we may be getting somewhere. I do get my water tested every year and it is a bit high in alkalinity. I think I just went from really confused to just a little.I think the issue maybe that your tap water contains alkalinity, while the simplified example above does not. Do you know what's in your water?
Alkalinity will raise the mash pH, so if you have more absolute amounts of alkalinity in the mash with a thinner mash, it can raise the pH.
The Ca from CaCl2 and CaSO4 is what lowers pH in the mash from mineral additions (but only through reactions with the mash; they aren't a good way to lower pH otherwise in, say, plain water). Adding NaCl won't affect the mash pH, for example.
So my guess is that you have enough alkalinity in your water such that its effect is greater than the other mineral additions that you are putting in.
Aha....we may be getting somewhere. I do get my water tested every year and it is a bit high in alkalinity. I think I just went from really confused to just a little.
Good to know it's me and not the software (which I assumed anyway). Thanks for the replies.
Bingo. Case 2 is a logical simulation. Nice work.Case 4 may be like your water, with alkalinity and added CaCl2 and gypsum. Case 3 is the same but without the alkalinity, so you can see how the Ca from the salts is affecting the mash pH, as long as it isn't being countered by the alkalinity.
Completely agree.Using RO water without any additions doesn't seem to be a good idea anyway.
Just to play with the spreadsheet more:
Going back to the no additions water, it seems that the calculations going on in the background plateau the pH at 5.76 with thin mashes, and the pH falls off once you start to get to unrealistically thick mashes. This has no bearing on what happens in the real world, but was amusing to play with:
640qt/lb pH = 5.76
64qt/lb pH = 5.76
16qt/lb pH = 5.75
8qt/lb pH = 5.74
4qt/lb pH = 5.72
3qt/lb pH = 5.71
2qt/lb pH = 5.68
1qt/lb pH = 5.61
0.5qt/lb pH = 5.46
0.25qt/lb pH = 5.16
0.125qt/lb pH = 4.55
0.0625qt/lb pH = 3.35
0.004qt/lb pH = 0.10
But within real world conditions, the spreadsheet seems OK. Using RO water without any additions doesn't seem to be a good idea anyway.![]()
Well, 0.004 qt/lb is pretty insane as well, lol. But the software doesn't know that.0.10 pH is utterly insane.
Well, 0.004 qt/lb is pretty insane as well, lol. But the software doesn't know that.
Software is never intended to know anything (at least until computer self awareness is achieved, which is left for the future). But someone knows.
Why does the diluted pH oddly plateau after a relatively inconsequential Mash pH prediction rise of about 0.06 pH points at one end of the water volume dilution/concentration spectrum, while going insanely exponential at the other end of the very same spectrum? It seems to me that the way out of this anomaly, which exhibits error at both ends of the spectrum, is to ignore buffered pH change with dilution/concentration an accept that (as supported by the work of D.M. Riffe and Mick Spencer) the simple answer is to not show any pH change with dilution/concentration.
I use your Mash Made Easy for my brews. Trying a similar setup in it (version 11.10) shows that changing mash water volume does not change pH for RO/distilled water, which is more in line with an expected real world result, although I think that adding 160 gallons of RO water to a 10 pound mash probably would change the pH some. At one of these ridiculous scenarios the dilution would have to overcome the buffering ability of the mash, wouldn't it?
I used the Bru'n Water calculator as well for my first BIAB yesterday. pH of the mash came out at 5.4. OG was targeted at 1.065 and I hit 1.069. So all went well and a good learning experience.Good thread guys. Been enjoying this one. To the OP, FWIW, I also think going with RO/distilled is the way to go. The water chemistry stuff seems daunting at first, but if you learn about it in small doses, it becomes more digestible.