So I got my new pH meter. And according to the Bru'n instructions, I check my mash pH 5-15 minutes after dough-in. But if it's been sitting there for 5-15 minutes, and I check and my pH is too high, isn't it too late to adjust? Or is this "now you know for next time" territory?
Quick question on adjusting mash pH
- Thread starter Calypso
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Hermit
fuddle
Unless you do a mini mash then yes, it is probably too late. You can do an adjustment if you want. I have. (I was at 150F and pH of 5.8. I got it down to 5.6 pretty quick but I was ball park to start) The lower you are mashing at and the slower the conversion the more the outcome will be affected. At 158 some people that check their conversion swear they are done in 20 minutes.
If the pH was only a tenth or so too high, then you might let it go. If its much above that, then you really should add acid to try and bring the kettle wort pH down to a reasonable range so that the hop and bittering character isn't rough.
Calypso
Well-Known Member
How accurate are the estimates in the Bru'n sheet? If it estimates, for example, that I need 10 mL of Some Acid Or Other (tm) to bring it down to my target pH, should I add that much before dough-in and see how it goes, or do I start with less than it recommends (half, maybe) so I have room to adjust?
They are estimates... meaning precision is variable. That said, I find Bru'n pretty accurate, and when it isn't - there has been a user input error on my part. If you are nervous about how much acid to add, I would suggest a test mash with a very small portion of the grist to calculate, and then titrate the acid to find the right amount. I tend to do this now when I have a large percentage of specialty or adjunct in a new recipe to give me the confidence to proceed with a full mash. That said - usually Bru'n is very close on the acid estimation.
While you can titrate your mash down with acid as needed till you hit your expected number, be aware that those numbers will continue to change past the 15 minute mark, and it will be easy to overshoot your desired target. The mash is a dynamic system. I have brewed and measured enough to have pretty good confidence in Bru'n's estimates. (not sure that punctuation is correct ?!?!) I find that at 10 minutes, my mash pH is slightly higher than my target, and by 15-20 minute is usually very close, and at the end of the mash, might be slightly lower.
This also assumes you are using a calibrated and stable pH meter properly and measuring at room temperature. Targeting a 5.4 mash pH also has a bit of fail safe built in - meaning that any reading +/- 0.1 still puts you into a very good range for most beers.
Take measurements consistently at room temperature, note them in the recipe and make the appropriate adjustment next time you brew it. Make notes when you taste the final product and correlate to the mash pH where possible. Brew again at a different target and compare the notes and observe the differences. That really is the best way to get a handle on the procedure and improving the overall application.
While you can titrate your mash down with acid as needed till you hit your expected number, be aware that those numbers will continue to change past the 15 minute mark, and it will be easy to overshoot your desired target. The mash is a dynamic system. I have brewed and measured enough to have pretty good confidence in Bru'n's estimates. (not sure that punctuation is correct ?!?!) I find that at 10 minutes, my mash pH is slightly higher than my target, and by 15-20 minute is usually very close, and at the end of the mash, might be slightly lower.
This also assumes you are using a calibrated and stable pH meter properly and measuring at room temperature. Targeting a 5.4 mash pH also has a bit of fail safe built in - meaning that any reading +/- 0.1 still puts you into a very good range for most beers.
Take measurements consistently at room temperature, note them in the recipe and make the appropriate adjustment next time you brew it. Make notes when you taste the final product and correlate to the mash pH where possible. Brew again at a different target and compare the notes and observe the differences. That really is the best way to get a handle on the procedure and improving the overall application.
Newbie here... Duhh What's Bru'n? Software or what?
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It's a nice water spreadsheet, with a lot of good brewing water information. It helps predict mash pH as well as help to tweak flavor additions and/or acid adjustments in sparge water if needed.
Can you see signatures? If you can, look at post #3 by scrolling up, and the link to brun'nwater is in the author's signature.
SpeedYellow
Well-Known Member
Some find the estimates accurate, others do not. Does your base malt have a distilled water pH equal to the baseline assumption for that malt in the software? If you can't answer that, then you shouldn't expect much accuracy, as it'll be a matter of luck.
Calypso
Well-Known Member
What is a distilled water pH? I have a pH meter, if that helps.
SpeedYellow
Well-Known Member
If you make a mash with each malt and distilled water, you'll get a certain pH, lets say 5.7 for pilsner malt and 5.4 for crystal 20. This is the main input in the calculators. But instead of requiring you to input the values, they assume certain values. But if your particular malts don't match we'll with their assumptions, then it won't predict well. And this is a non-trivial source of error.
Best thing you can do is make a test mash (e.g. 1 lb) before every batch. That's kind of a pain. Second best thing is to make a test mash using 100% of your couple favorite base malts. Then you can correct the assumptions in the calculators and it'll predict fairly well when you use those malts. Worst thing you can do is simply run the spreadsheet "as is", but even then you'll usually be within 0.2. All depends how accurate you want to be.
It is actually quite simple to predict mash pH accurately if you have a good model and good data on the individual malts. The good model is pretty simple. Getting good data is not so simple but there is some out there. It would be great if the maltsters would give the necessary data as part of their specs but there is some data out there on a handful of malts.
When you say "make adjustments next time you brew" if using Bru'n Water spreadsheet is the adjustment merely a "mental one", i.e., last time I brewed this recipe I measured a pH 0.2 higher the BNW target, so, I should target in ssheet results pH -0.2 lower than I truly desire? I see no mechanism in BNW to adjust the congress pH of each malt type based on doing my own DI water test mash with each malt type I might use.
I build up my water from DI water using Bru'n Water as my guide. I'm just curious how to leverage results of actual mash pH measurements vs. "chasing the numbers" real time by adding additional acid risking an undershoot or adding alkalinity and risking and overshoot plus screwing up my desired mineral profile from target. Or, relax, have a home-brew and let the pH fall where it falls trusting that Bru'n Water calculations are "close enough"
I haven't invested in a pH meter yet. My beers have tasted fine, but, my mash efficiencies (EIK) doing BIAB have been in the mid to upper 60's % doing 90 min mashes with grain I crush myself (getting a good crush). I figured pH is my only remaining variable to tweak to affect EIK.
Yes, that's what I would do.
You will learn, if you use them a lot and make measurements when you brew, that Brun water tends to come in low, that EZ water tends to come in high and that Brewer's Friend tends to come in about right (depending to some extent on the beer). I should note that I don't use any of these so my comment is based on what I gather from what people say here and you may find things different. In any case, you will learn from experience what errors to expect for the particular beers you brew assuming that your materials are consistent e.g. that your water supplier doesn't switch from surface water to wells in the summer months or something of that sort. If Bru'n comes in 0.2 high for a particular beer then simply set its target 0.2 lower and use half the extra acid. If it's model isn't right on DI mash pH it probably isn't right on buffering capacity either and you don't want to overshoot. It may take a couple of iterations until you get zeroed in but at that point you will know how much acid (or alkali) to use for your mash materials.
I think one of the spreadsheets will let you do that - guess it must be EZ because Brewer's Friend not Bru'n Water do (AFAIK). If you want to be able to put in actual malt data you can start with something like the spreadsheet at http://www.wetnewf.org/pdfs/Brewing_articles/MashpH.xlsx. As that spreasheet was put together for a presentation to MBAA you should probably also grab the slides (http://www.wetnewf.org/pdfs/Brewing_articles/MBAA_FREDERIC.pptx) so you understand how the spreadsheet works.
This spreadsheet wants not only DI mash pH but a three term Taylor series model for the malt's actual titration curve. The first term is the buffering capacity of the malt at the DI mash pH and the other terms let the spreadheet calculate the buffering capacity at other mash pH's. Kai has measured the average buffering capacity of several malts. The data are on his web site. This does not give as accurate a model as detailed measurements which yield the other two terms but if you use DI mash pH and the average buffering for the first term you will very likely get better results than if you specify only color or type of malt.
All this is more or less moot until you obtain the means for accurate pH measurements both so you know what you are realizing in the mash and so that you can get malt data if you want accurate predictions, accurate test mashes etc.
The chasing mash pH comment is in context to an active mash. I believe AJ will agree that mash chemistry is dynamic and variable to the extent that many factors (agitation, mash thickness, quality of malt, quality of minerals/acid/etc) come into play. Adding additional acid or alkalinity to an active mash will need time to complete incorporation into the entire mash, and the affected result may take 15-30 minutes to stabilize. That is a long time when doing a 60 minute mash! Making measurements and adjustment 5 minutes apart will not allow the chemistry to stabilize for a more accurate measurement - hence the chasing your tail comment. If you see that Bru'n is somehow 0.2 points low - then check your work to make sure something is not in error.
I am disciplined to only make a single adjustment to a mash, and only when it measures outside my required range, say between 5.3 and 5.5 and have precalculated additions to move the mash 0.1 unit in either direction. I have not had to do this in the last 20 or so brews. Bru'n Water estimates have been very close, within +/- 0.05 units, despite AJ's statement. I have not seen Bru'n consistently estimate low, and suspect that there maybe some user error issues at play, OR lack of precision in the brew house. I am quite confident in my methodology and the results. As AJ has mentioned - using such a tool without a basic understanding of the chemistry can result in bad results.
IMO the test mash is the most accurate solution, but also requires an extra step that most brewers will not do. I don't personally like taking the time, but I will on a batch intended for competition. So a congress mash, with the mineralization I intend, and estimated acid or alkalinity to achieve a target mash pH. I measure pH 4 times during the test mash at 15 minute intervals. The first 15 minutes I expect to be slightly below my target pH and usually observe pH rise slightly into the right zone around 30 minutes. The last measurements are really verification. Of course, this requires the good quality pH meter, and one that is stable and calibrated and maintained. I check the results against estimates in Bru'n.
I am disciplined to only make a single adjustment to a mash, and only when it measures outside my required range, say between 5.3 and 5.5 and have precalculated additions to move the mash 0.1 unit in either direction. I have not had to do this in the last 20 or so brews. Bru'n Water estimates have been very close, within +/- 0.05 units, despite AJ's statement. I have not seen Bru'n consistently estimate low, and suspect that there maybe some user error issues at play, OR lack of precision in the brew house. I am quite confident in my methodology and the results. As AJ has mentioned - using such a tool without a basic understanding of the chemistry can result in bad results.
IMO the test mash is the most accurate solution, but also requires an extra step that most brewers will not do. I don't personally like taking the time, but I will on a batch intended for competition. So a congress mash, with the mineralization I intend, and estimated acid or alkalinity to achieve a target mash pH. I measure pH 4 times during the test mash at 15 minute intervals. The first 15 minutes I expect to be slightly below my target pH and usually observe pH rise slightly into the right zone around 30 minutes. The last measurements are really verification. Of course, this requires the good quality pH meter, and one that is stable and calibrated and maintained. I check the results against estimates in Bru'n.
SpeedYellow
Well-Known Member
That surprises me, because in my limited use of Bru'n Water, I've seen some poor estimates. E.g. here's my last beer -- Bru'n Water predicted 5.1 (!), actual was 5.5 (measured, calibrated). Way off.
8.4 lb / 2-row/ 3L
2.0 lb / Munich / 8L
1.0 lb / Caramunich / 12L
1.0 lb / Victory / 25L
0.5 lb / Carafoam / 2L
Distilled water with modest gypsum & CaCl
Bru'n Water predicted: 5.1
EZ Water predicted: 5.5
ACTUAL = 5.5
Yes, I do agree with that.
I always say that if something doesn't look right it probably isn't right and experience has taught met that this is usually, but not always the case (see comments above about all the factors). Unfortunately, the only way to gain the instinctive insight of which I speak is lots of experience. There is another thread in Science where I believe the poster also saw an unusually low pH prediction from Bru'n water. In this case it was confirmed by a pH meter reading but it still didn't make sense in terms of what one expects of normal base malts, normal caramel malts etc. So what do you tell this fellow? Exactly what it says above - go back and check everything and repeat the measurements multiple times.
This is, of course, more likely to happen to a new brewer than an experienced one and a new brewer is, of course, more likely to mismanage the adjustments and wind up chasing his tail.
Experience at work!
I must reiterate that my comments about Bru'n Water, Brewer's Friend and EZ Mash are not based on a Consumers Report set of comprehensive tests but more on what I see people report here. Once the notion that Bru'n is low (Martin has mentioned that he gets complaints about this), BF about right and EZ high gets abroad then we have, in addition to concerns about relying on anecdotes, to consider that confirmation bias may be creeping in.
We could look deeper for explanations as to why Matt gets accurate predictions and others don't with any of these tools but that's going to be a tough job as I don't really know how any of them work. I believe that Bru'n is based on collected empirical observations by lots of brewers. I believe BF attempts to work out the acid base chemistry using titration data collected on a bunch of malts. I have no idea how EZ works. In the case of the first two we have to ask how global the emprical data was (did it include mostly ales or a mix of ales, lagers, wheats.....?) and in the case of Bru'n and in the case of BF how global was the ensemble of malts tested and how well does the collected data correlate with color (as malt quality is input as its Lovibond color rating). Depending on these answers it is quite feasible that Matt is brewing beers that are typical of the Bru'n ensemble and that might explain why he gets good agreement. At the same time some of these folks who notice low predictions may be doing unusual things (or at least unusual in terms of the ensemble). This would explain things but I certainly cannot assert that it is indeed the explanation.
Again experience can be your friend here. If you consistently brew the same beers or the same types of beers you should have a pretty good idea as to what to expect unless someone throws you a curve ball such as your water company changing source or a maltster receiving a crop of barley that is unusually alkaline.
Also, if you have a program that consistently gives you good predicitions then you can rely on that as you have verified that its model is viable for your application.
SpeedYellow - I would guess that you should email Martin on such a wide difference - he needs to root cause determine if there is a problem with his algorithm. I should also note I use the supporter version - so while I haven't noticed any calculation differences between that and the free version - there may be some. I use the free version when I am helping folks privately and encourage them to get the supporter version. I have found Brewer's Friend and Bru'n Water to be fairly close... but never exactly the same in prediction. Granted the comparisons were made about 2 years ago - and Brewer's Friend may have improved greatly. I should check it out again.
PLEASE DO NOT take this as criticism. There are so many things that can contribute to problem during mashing... like forgetting I already added acid and doubled up, or added an extra 1/2 lb of crystal on a whim or got my strike volume wrong... yada yada. Without taking detailed notes, I would have not noticed my changes to my plan - and be able to account those differences. I had a bad early experience with EZWater, and observed consistent and significant deltas between prediction and measurement. I never adjusted DI acidity for grist in EZ which might form a better result. We both seem fairly confident in our positions. I can only report what I observe same as yourself.
AJ you make a good point. I seldom brew a beer that I would consider an edge case. I also work very hard to eliminate variability in the brewhouse and cellar, and double/triple check my plans and checklists... I have a ways to go to consider myself a very experience brewer however. Also good point on confirmation or even observational bias - I am sure it is possible. I like, am familiar with, and confident in Bru'n - hence I am a vocal supporter - I am hardly a neutral party. I am planning to brew again this week, maybe I should run a comparison between all three predictions and actual measurements.
Unfortunately, it appears that there is a substantial error in the application of the program. I'm not sure how one could create that much error without some sort of input error. With your parameters shown above, I show that the pH would be about 5.45 with 50 ppm Ca. If you used a lower Ca content, the prediction is even closer.
I'm sorry that you had difficulty in using Bru'n Water properly, but it appears that the prediction would have been correct if the program was utilized correctly.
SpeedYellow
Well-Known Member
Thanks Martin, but I'd like to see how you got 5.45. Here's a screenshot with the malt bill above, showing 5.1. The adjusted water is around 50ppm Ca.
Thanks everyone for the informative dialog. I've ordered a Milwaukee MW102 pH/temp meter which should arrive tomorrow (Friday) in time for my brew day Sunday of batch 2 of my Guinness clone. I've got my DI water adjustments from Brun Water for a Wicklow Mountain water profile with a target mash pH of 5.2. I've been building my water up from DI water the past 5 batches. I'll find out Sunday where I land 
.
Sent from my iPad using Home Brew
.Sent from my iPad using Home Brew
Victory is roasted malt? Id have called it base.
Sent from my iPad using Home Brew
You must have added some acid on the water adjustment page or something. Even with victory listed as a roasted malt (it should be crystal malt for the purposes of the program...basically anything < 200L that's not a base malt should be) I get 5.3. If I list victory as crystal I get 5.4 for a prediction. EDIT: 1ml of lactic acid would give me the 5.1 reading if I listed victory as roasted.
I see that you are using an ancient version of Bru'n Water. For the pH to have been reported as 5.1 in version 1.16 of the sheet, the Net Mash Acidity will be about 3.8 and your sheet shows 2.9. We conduct upgrades for a reason...better information leads to better models. I suggest you revisit your findings when using the latest version.
PS: Victory malt isn't anywhere near a roast malt. Entering it as such will guarantee a poor result. Base malt is more appropriate.
I Googled my own question and found Palmer...
Victory Malt 25 L This roasted malt is similar in flavor to Biscuit but gives a more nutty taste to the beer. Victory adds orange highlights to the beer color.
http://www.howtobrew.com/section2/chapter12-1.html
And Briess
http://www.brewingwithbriess.com/Products/Roasted.htm
Not unreasonable that OP decided to call Victory a Roasted malt.
Victory Malt 25 L This roasted malt is similar in flavor to Biscuit but gives a more nutty taste to the beer. Victory adds orange highlights to the beer color.
http://www.howtobrew.com/section2/chapter12-1.html
And Briess
http://www.brewingwithbriess.com/Products/Roasted.htm
Not unreasonable that OP decided to call Victory a Roasted malt.
Even if the model is perfect, GIGO.
This is why it is so important that programs that estimate mash pH do it based on measurements of the malt rather than type, color.... I say this in full recognition of the fact that someone has to make the measurements and the only party that could reasonably be expected to do that effectively would be the maltster himself. Before they'd do this the following would have to happen:
1) Demonstrate that it is possible to accurately predict pH from properly made malt measurements
2) Have the commercial (craft) brewers decide that being able to predict mash pH is desirable to the point they pressure the maltsters to provide the data
3) Have the maltsters respond to their customers demand.
Only the first pass at 1) has been done so don't hold your breaths.
I've measured two Pilsner malts from the same maltster and found one to have a DI mash pH 0.2 lower than the other with 33% higher buffering capacity.
This is why it is so important that programs that estimate mash pH do it based on measurements of the malt rather than type, color.... I say this in full recognition of the fact that someone has to make the measurements and the only party that could reasonably be expected to do that effectively would be the maltster himself. Before they'd do this the following would have to happen:
1) Demonstrate that it is possible to accurately predict pH from properly made malt measurements
2) Have the commercial (craft) brewers decide that being able to predict mash pH is desirable to the point they pressure the maltsters to provide the data
3) Have the maltsters respond to their customers demand.
Only the first pass at 1) has been done so don't hold your breaths.
I've measured two Pilsner malts from the same maltster and found one to have a DI mash pH 0.2 lower than the other with 33% higher buffering capacity.
SpeedYellow
Well-Known Member
Victory malt is a roast malt, period. We all know that. If your software can't handle known truths, then it's a problem with the software, not the user. Which raises the question - what other truths are we supposed to disregard in order to make Bru'nWater work properly?
Using the current version (just 9 months newer than mine) brings the pH up to a more reasonable 5.3, still low but at least reasonable. You apparently have to cheat the inputs to arrive at your 5.45 pH.
p.s. if we pay you for the software, do you stop belittling and berating us?
I can't seem to verify at the moment (My Libre spreadsheet app isn't showing the comments from the spreadsheet), but I think the comment on the grain type column mentions roast malt starting at 200L, though admittedly one would have to hover over the column header.
It doesn't but this would be nice point of clarification to add to the comment. (at least in my version 1_16). Could also mention Victory and Biscuit under base malts to further clarify.
FWIW in the current version of the spreadsheet I get a 5.3 if I call Victory roast and a 5.4 if I call it Base. Not a big deal and seems to be decent prediction of Yellow's actual 5.5 result. Seems if I send MB a small donation I could have another digit on that prediction and get his 5.45 instead of my free 5.4 but in fact either 5.3 or 5.4 is close enough to predicted 5.5 for my purposes. If I had predicted a 5.1 though I might have added some bicarb to my mash water and come in too high.
I don't think anyone should have felt berated. Yellow made a point that the calculation was way off, Martin responded and clarified the matter. Biggest issue by far was using the old version of Bru'n water which apparently has been updated more than cosmetically.
In regards to its acidity, it isn't anything like a roast malt, though. Perhaps he should add a comment somewhere to that affect, but it seems to me like you're berating him for his FREE spreadsheet.
Does anyone know what its DI mash pH is?
Perhaps someone who has a bit at hand could check that. With that number we could WAG buffering at 35 mEq/kg-pH and determine whether it is roast, base or caramel.
Perhaps someone who has a bit at hand could check that. With that number we could WAG buffering at 35 mEq/kg-pH and determine whether it is roast, base or caramel.
SpeedYellow
Well-Known Member
Actually, its acidity is EXACTLY like a roasted malt, specifically a 25L roasted malt, because that's what it is by definition -- a 25L roasted malt. It's certainly not a crystal malt, even if its acidity may be similar.
Blah, blah, you're being pedantic. You knew what I meant, but I'll rephrase. It doesn't act like a dark roasted malt, which is what the option is meant to be used for.
Hermit
fuddle
So does this make it the same as Dark Munich?
http://braukaiser.com/wiki/index.php?title=File:Charts_base_malt_DI_pH.gif
To be honest I've never seen any one say that the lightly roasted malts should be considered base malts for this purpose. I can see why people say to use base/crystal as that seems to be more linear.
http://braukaiser.com/wiki/index.php?title=File:Charts_base_malt_pH_and_malt_acidity.gif
http://braukaiser.com/wiki/index.php?title=File:Charts_base_malt_DI_pH.gif
To be honest I've never seen any one say that the lightly roasted malts should be considered base malts for this purpose. I can see why people say to use base/crystal as that seems to be more linear.
http://braukaiser.com/wiki/index.php?title=File:Charts_base_malt_pH_and_malt_acidity.gif
SpeedYellow
Well-Known Member
Sure it sounds pedantic but I was quite serious. It might have less acidity than darker roasted malts (which itself is an assumption on our part) but more importantly, why do you say it acts differently from other roasted malts that the Color data input doesn't account for? I.e. don't we enter the Color so that this can be accounted for?
Sounds like none of us knows the distilled water pH of Victory, so it might be that BruNWater calculates it perfectly as a 25L Roasted Malt. We're all just speculating.
But we do know Victory is not a crystal malt, nor a base malt.
Color isn't a particularly good proxy for malt titration properties. If you try to fit a linear model to Kai's measurements of caramel/crystal (i.e. separating roast out as his data clearly shows you should) you find that the color is only able to predict 77% of the variation. But as the variation is large (1 pH unit) the unmodeled 23% can be significant. The rms error between Kai's data and a linear model derived from it is 0.19 pH. An exponential model is better but even that results in rms error of 0.10 pH.
The reason you can pick different type names for Victory in the spreadsheet without seeing huge differences in predicted pH is because this malt is only a portion of the grist. The big swinger is, of course, the base malt. The programs would have to be able to distinguish between Weyermanns pneumatic pils malt and their floor malt as the DI mash pH difference, mentioned earlier, is 0.2.
The reason you can pick different type names for Victory in the spreadsheet without seeing huge differences in predicted pH is because this malt is only a portion of the grist. The big swinger is, of course, the base malt. The programs would have to be able to distinguish between Weyermanns pneumatic pils malt and their floor malt as the DI mash pH difference, mentioned earlier, is 0.2.
So whether it is user error or an unusual malt mixture or the alignment of the planets sometimes it should be expected the measured pH will be different from that that was predicted in the calculator (whichever calculator).
I really liked Chrispen's idea back a few pages and wish I had a brew day calculator to support this...
I know he has the discipline to pre-calculate these additions...but I am looking for something, accessible from phone or tablet, that would take the necessary inputs...current room temp pH, desired room temp pH, pounds of grist, volume of liquor (not sure that is required variable), then give me a recommended acid or pickling lime addition to get what I am looking for. I'd use it like I use my decoction calculator in beer alchemy to come up with a quick decoction volume when I undershoot mash temp. I understand the concerns about dynamic conditions and garbage in garbage out but I am really looking for the right addition to get to within .1 or .15 pH from target in those situations where measured pH is say .3 pH high or low. Might be nice if the calculator included different acids sources as well as different bases (is bicarb used here?).
I really liked Chrispen's idea back a few pages and wish I had a brew day calculator to support this...
I know he has the discipline to pre-calculate these additions...but I am looking for something, accessible from phone or tablet, that would take the necessary inputs...current room temp pH, desired room temp pH, pounds of grist, volume of liquor (not sure that is required variable), then give me a recommended acid or pickling lime addition to get what I am looking for. I'd use it like I use my decoction calculator in beer alchemy to come up with a quick decoction volume when I undershoot mash temp. I understand the concerns about dynamic conditions and garbage in garbage out but I am really looking for the right addition to get to within .1 or .15 pH from target in those situations where measured pH is say .3 pH high or low. Might be nice if the calculator included different acids sources as well as different bases (is bicarb used here?).
I have this chart in my brew room: http://braukaiser.com/wiki/index.php?title=Mash_pH_control (Scroll all the way down). Is that what you're looking for?
It is quite conceivable that what you want would be pretty easy to put together (by someone with programming skills for the devices you referred to). You are looking at small pH changes (a couple of tenths) and over a small range like that the buffering capacity (titration curve) of each malt will be nearly linear so the amount of acid required for an adjustment of DpH will be DpH*B*M where B is the buffering capacity and M is the mass of the grain (kg). So the question becomes what to use for B. The number will probably be between 30 and 50 mEq/kg-pH so 40 might be a good place to start experimenting. We would hope that the effects of averaging over grains might keep the dispersion about 40 small. At the same time we have to keep in mind that if we use 40 and the actual number is 30 that we will calculate 33% more acid than needed and conversely so it will be necessary to check the results and probably wise to add only a fraction of the computed amount unless willing to accept a pH potentially lower than ideal.
DpH*B*M is in units of mEq. It is a simple matter of knowing the strength of the acid you wish to use. 88% lactic is about 11.8 N (contains 11.8 mEq acid per cc).
DpH*B*M is in units of mEq. It is a simple matter of knowing the strength of the acid you wish to use. 88% lactic is about 11.8 N (contains 11.8 mEq acid per cc).
Yooper, this one?
Eric, I will use the spreadsheet to note first the estimated target pH and (usually) the acid necessary to achieve that. Working from there, I figure out how much baking soda or pickling lime to raise that 0.1 units and note it... then reverse that out and note the liquid acid addition necessary to move 0.1 unit lower. It is convenient as I use the spreadsheet to plan anyway. Because I use RO, the amounts required are typically small and are based on the buffering of the mash, and from my notes very similar to the amounts in the chart.
