pH of Maris Otter
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JJL
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That's what I am using, but the calculator does mention certain malters make grains that have different pH levels. I thought I read somewhere that Maris otter was 5.6 in distilled water, yet the calculator figures in 5.77.
I've measured it at 5.6 but that was one sample from one maltster. I did a stout a couple of weeks back using it as the base with 10% roast barley and got 5.6 for the mash pH which certainly suggests that the MO only pH was higher. And I'm sure 5.77 wasn't just pulled out of the air. IOW it varies and the only way to know what you are dealing with is to make a measurement.
What is mash temp (beta glucan rest, protein rest, saccharification rest)?
In any case 5.4 - 5.6 is OK at room temp.
In any case 5.4 - 5.6 is OK at room temp.
MachineShopBrewing
Well-Known Member
Was that using R/O water, or did you add back some minerals? I use R/O water with either a tsp CaCl or CaSO4 per 5 gallons depending on beer style and I typically get a reading of 5.0-5.2 for recipes without much roast/crystal malt, and a reading of 4.8-5.0 for recipes with 10%+ roast/crystal malt. I do all of my readings at ~25C with a meter that is calibrated at ~25C. This data is over about 20-25 batches of different recipes.
I find that I usually need to add some pickling lime to get the pH back to the range I want it. This has always made me wonder, as most people say that you typically need to push the pH down rather than up, but I find that I am usually having to move it up.
As I have learned to anticipate, I have started adding some lime right to the water the night before when I add the other salts.
I have not had the R/O water tested for the remaining mineral content, but it is a culligan system in a wal-mart and it does get routine maintenance every month.
Sorry to partially hi-jack, but I guess it is slightly on topic.
DI water.
I don't question that you saw what you saw but I don't see how it is possible. I measure MO at 5.6 or higher in DI/RO water, as noted above. In RO water with 5 grams of CaCl2 or gypsum a base malt only mash would be expected to come in at 0.08, call it 0.10 lower than the DI water mash or, in the example I measured, minimum 5.5. And that is about where I measure MO mashes even with a fair amount of colored malts (Barley wines and stouts are the only non German ales I do). It always takes an acid addition to get below this. And it is consistent with what's in the brewing texts and, AFAIK, other peoples' experiences. So I am totally mystified as to how you could be getting as low as 5.0 for what is essentially a base malt mash.
A couple of questions:
What do you measure for base malt only dough in pH?
Are you using fresh, pH 4 and pH 7 buffers?
Are you rinsing the electrode with DI water and blotting or shaking between the 2 buffers and between sample and buffer?
What is the precision of your pH meter?
What's the pH of the RO water?
To me it seems the possibilities are:
1) problem with pH meter
2) bad calibration (from bad/old/contaminated buffers) and/or bad technique
3) RO water contains acid
4) super acidic MO or colored malts
5) "without much" means much less to me than it does to you
Don't think it's a hijack at all.
MachineShopBrewing
Well-Known Member
I have been mystified as well. My mashes are not quite base malt mashes, but it still seems weird why I am usually going up instead of down.
Now that I am home, I went back through my beersmith files to look at some sample mashes.
12.00 lb Pale Malt (2 Row) US (3.0 SRM) Grain 90.57 %
0.50 lb Cara-Pils/Dextrine (2.0 SRM) Grain 3.77 %
0.50 lb Wheat, Flaked (1.6 SRM) Grain 3.77 %
0.25 lb Amber Malt (22.0 SRM) Grain 1.89 %
This one came in at 5.10 with R/O + 1 tsp CaSO4 per 5 gallons. This one I brewed at a friends house and I had him double check with his pH meter for the very same reason that I posted in this thread. I have been suspect of my meter or my methods. Both readings with both meters were +/-.03 pH of each other.
10.00 lb Pale Malt (2 Row) US (2.0 SRM) Grain 86.96 %
0.50 lb Cara-Pils/Dextrine (2.0 SRM) Grain 4.35 %
0.50 lb Corn, Flaked (1.3 SRM) Grain 4.35 %
0.50 lb Munich Malt - 10L (10.0 SRM) Grain 4.35 %
This one came in at 5.35 with 1/2 tsp CaCl and 1/2 tsp CaSO4 per 5 gallons.
7.00 lb Pale Malt (2 Row) UK (3.0 SRM) (MO) Grain 73.68 %
1.00 lb Caramel/Crystal Malt - 40L (40.0 SRM) Grain 10.53 %
0.50 lb Honey Malt (25.0 SRM) Grain 5.26 %
0.50 lb Munich Malt (9.0 SRM) Grain 5.26 %
0.25 lb Caramel/Crystal Malt -120L (120.0 SRM) Grain 2.63 %
0.25 lb Chocolate Malt (200.0 SRM) Grain 2.63 %
This one came in at 4.9 with 1 tsp CaCl and 1/2 tsp Pickling Lime added to the water the night before. I corrected with another 1/2 tsp Pickling Lime and checked post boil going into the fermenter and it was 5.23.
My beers have been coming out great regardless, but it has been bugging me. I have sealed containers that I store the buffers in between calibrations. I do spray the electrode off with DI water and shake off the excess before going between buffers. I go through buffers every couple of months.
I use an MW-102 meter with auto calibration and temp correction.
I have not checked the R/O water before mashing. I will make a note to do that with the next batch.
On a side note, that may or may not be relevant, I never treat my sparge water with any minerals or acids. I will usually(if I remember) add an additional tsp of either CaCl or CaSO4 to the boil to get my Ca up for fermentation.
Cheers
I have to admit that my results are similar to Machine's when using RO water. I can produce and measure fairly low mash pH under some grist conditions.
I can't really decipher his water chemistry since he is using teaspoons and he might as well be using hand-grenades. A scale is the only (modestly) accurate way to know what you're adding to your water. At least he has a consistent way of measuring his additions and I suppose that counts for something!
About a year ago, I made an English Mild that included 20% crystal malts in the grist. That is a pretty extreme crystal content in my experience, but that is what this 'award winning' recipe used. I created a very modest water profile using RO water and primarily CaCl2. Bru'n Water said I needed to add alkalinity, but I figured I would see if the mash really was going to need it. I doughed in and measured a room-temp mash pH of 4.9! I went ahead and added the mass of pickling lime that my program had calculated. The mash pH rose to 5.4.
At that time, I was under the impression that the mash chemistry had a natural buffering tendency to limit the pH drop at about the 5.2 range. The beer mentioned above changed that perspective. When I plotted the result of that beer's mash with all the other mashes conducted by me and a half dozen other brewers, that 4.9 mash pH plotted right in line with the other data. I was very surprised, but I could not dispute it.
I do not know why these empirical results differ from AJ's and Kohlbach's, but I do know that I see a consistent offset of about 0.15 units lower than what Kohlbach's values indicate. I have hypothesized that there is some sort of decarbonation effect upon heating, but that would be minor when starting with a low alkalinity water like RO.
Curious.
PS: Machine, since you're using RO water, you don't need to acidify or add minerals to the sparge. What you're doing is fine.
I can't really decipher his water chemistry since he is using teaspoons and he might as well be using hand-grenades. A scale is the only (modestly) accurate way to know what you're adding to your water. At least he has a consistent way of measuring his additions and I suppose that counts for something!
About a year ago, I made an English Mild that included 20% crystal malts in the grist. That is a pretty extreme crystal content in my experience, but that is what this 'award winning' recipe used. I created a very modest water profile using RO water and primarily CaCl2. Bru'n Water said I needed to add alkalinity, but I figured I would see if the mash really was going to need it. I doughed in and measured a room-temp mash pH of 4.9! I went ahead and added the mass of pickling lime that my program had calculated. The mash pH rose to 5.4.
At that time, I was under the impression that the mash chemistry had a natural buffering tendency to limit the pH drop at about the 5.2 range. The beer mentioned above changed that perspective. When I plotted the result of that beer's mash with all the other mashes conducted by me and a half dozen other brewers, that 4.9 mash pH plotted right in line with the other data. I was very surprised, but I could not dispute it.
I do not know why these empirical results differ from AJ's and Kohlbach's, but I do know that I see a consistent offset of about 0.15 units lower than what Kohlbach's values indicate. I have hypothesized that there is some sort of decarbonation effect upon heating, but that would be minor when starting with a low alkalinity water like RO.
Curious.
PS: Machine, since you're using RO water, you don't need to acidify or add minerals to the sparge. What you're doing is fine.
MachineShopBrewing
Well-Known Member
I have had good results using AJ's water for dummies method
I have been kicking around getting a good quality scale to measure my additions though. My current scale for hops and malts is just too large to measure accurately at small amounts.
Keep in mind also that I am not a scientist, nor do I play one on TV. And I didn't stay in a Holiday Inn last night either.
That is the way I figured it. I never understood when guys like Jamil and Gordon Strong talk about acidifying their sparge water when they are using R/O water. If the water has no/little buffering capacity, then it shouldn't matter. I'm not arguing with their results, but it always seemed like a waste of time to me.
Since I have been using a pH meter on my mashes, I have never had a mash come in higher than 5.4 without adding Lime.
I did a test mash with distilled and Muntons MO and it was 5.70 at 67.6F. It was at least 5 minutes into the mash if not more, I can find out if you want. It seems like MO has a higher pH than most malts so somewhere in the ballpark of 5.7 would be a good estimate if you can't measure. If you are concerned but can't get a meter, you could mail a sample of your malt to someone that has one and is willing to give you a reading.
There's nothing here to suggest that the pH should come in that low. I've seen reports that some US 2 ROW has a DI water pH as low as 5.5 but the only thing with any color in this mash (and not much color at that) is only there at less than 2%.
This one is almost believable. If you had base malt with DI pH of 5.5 and the calcium dropped you 0.1 you'd be at 5.4 and your meter's basic accuracy is ± 0.02.
At least you have quite a bit of dark malts in here so this one might also be believable if you hadn't added the lime. Lime is pretty powerful stuff.
Buffers are the only thing that I can think of that could be responsible for consistent bias. Buffers should be freshly made for each brew or drawn fresh from stock for each brew. Trying to use buffers for a couple of months is not a good idea. But even if you did do that I'd be surprised to see error as large as you are reporting.
The specs for this meter are for ±0.02 pH. That's adequate if the unit is in spec. On the occasions where people have brought me inexpensive meters and asked me to check them the thing I see is drift. IOW it takes a good cal but when you recheck cal 10 minutes later it is off 0.05 or 0.10. I assume this is instability in the electrode - not the electronics but it could be either or both.
I'd suggest, based on this, a post brew check of the meter i.e. at the end of the brew session put the meter back in the buffers and see if still reads 4.00 and 7.00 (or whatever they should at the temperature of measurement). I'm grasping at straws here but there has to be an explanation for this.
I'd be very surprised if you found a pH below 6 for the RO water and even if you did I doubt there would be much acidity behind it. Of more interest would be the RO water pH readings for the base malts you use.
I can see it happening under some grist conditions but Machine sees it regularly,
5 grams (approximate weight of a tsp) of calcium chloride in 5 gallons nominally pulls pH down 0.08. If his teaspoons were 10 grams that would only pull him down 0.18. He is seeing pH values much lower than could be explained by that.
I find that surprising but understand that some of these darker crystal malts have high titratable acidiy.
Malt does, of course, have some buffering capacity but the thing that is most predominant in it are phosphates and amino acids. Phosphate is a poor buffer at mash pH.
Me either but I'd like to. I have to assume that it is
1) Cheap meters don't work as well as I thought they did
2) You guys are obtaining malts that are a lot more acidic than the ones I (or Kolbach) am/was familiar with.
MachineShopBrewing
Well-Known Member
I have a sack of MO and a sack of Rahr 2-row. I could do a small DI mash and test the results.
What is the smallest reasonable mash size that I could do to get comparable results? Keeping in mind that it will just get tossed when done.
I think I still have a gallon or so of treated water left from the other day's brewing session. R/O with 1 tsp CaCl + 1/2 tsp Lime. I could test both the DI and the treated water.
I will grab some fresh buffers at the shop and see if it makes a difference.
This may be the case, but I usually calibrate immediately before checking pH the first time. Only the time it takes me to spray off the electrode with DI water usually. I will have to try checking it a few minutes later.
What is the smallest reasonable mash size that I could do to get comparable results? Keeping in mind that it will just get tossed when done.
I think I still have a gallon or so of treated water left from the other day's brewing session. R/O with 1 tsp CaCl + 1/2 tsp Lime. I could test both the DI and the treated water.
I will grab some fresh buffers at the shop and see if it makes a difference.
This may be the case, but I usually calibrate immediately before checking pH the first time. Only the time it takes me to spray off the electrode with DI water usually. I will have to try checking it a few minutes later.
It is the Rahr that is rumored to have the very low DI mash pH so that would be a good one to check. I tried to buy a little to test but at my LHBS it's a sack or nothing and I'd never use it.
A couple of oz. Put them in a small beaker or glass, mix with water at temperature sufficient to get to somewhere near your intended strike temperature, put the glass or beaker in a water bath and allow some time for everything to stabilze.
That might add something to the discussion. Calcium chloride isn't all calcium chloride. It usually contains some calcium hydroxide.
Always a good idea to have fresh buffers.
You should also be checking the mash pH at a couple of points in time.
MachineShopBrewing
Well-Known Member
How long would you hold it at mash temps before cooling to measurement temps?
Ten minutes should be enough especially if you pulverize it in a blender before adding water to it.
MachineShopBrewing
Well-Known Member
I have to run to the homebrew shop on saturday. I will pick up some new buffers and try doing some tests on Sunday and report back what I get with both the MO and the Rahr.
MachineShopBrewing
Well-Known Member
I was able to test the Rahr and the Crisp MO today. I did 56 grams of crushed malt and added to 150 ml of water. I tested with DI water and got 5.75 for the MO and 5.7 for the Rahr.
I will have to test in the future with the R/O water, as I didn't have any left from last brew session.
I did grab some fresh buffers from midwest supplies yesterday, so maybe that could have something to do with my previous results?
I was just going through my recipes and found this one that I thought was interesting
10.00 lb Pale Malt (2 Row) UK (3.0 SRM) Grain 67.80 %
1.00 lb Barley, Flaked (1.7 SRM) Grain 6.78 %
1.00 lb Oats, Flaked (1.0 SRM) Grain 6.78 %
0.75 lb Chocolate Malt (450.0 SRM) Grain 5.08 %
0.75 lb Roasted Barley (300.0 SRM) Grain 5.08 %
0.75 lb Victory Malt (25.0 SRM) Grain 5.08 %
0.50 lb Caramel/Crystal Malt - 80L (80.0 SRM) Grain 3.39 %
I recorded a 4.6 with 1 tsp CaCl and 1/4 tsp of Lime per five gallons on this mash according to my notes. That is the lowest one I could find and it was for a stout.
So now I think I need to test with the R/O water to see where the base malt comes in with that.
I did use some little plastic cups to hold the buffer solution this time rather than the little jars that I usually use. Perhaps the other jars may be contaminated for some reason. I don't think so, but not sure what else could be a factor.
I will have to test in the future with the R/O water, as I didn't have any left from last brew session.
I did grab some fresh buffers from midwest supplies yesterday, so maybe that could have something to do with my previous results?
I was just going through my recipes and found this one that I thought was interesting
10.00 lb Pale Malt (2 Row) UK (3.0 SRM) Grain 67.80 %
1.00 lb Barley, Flaked (1.7 SRM) Grain 6.78 %
1.00 lb Oats, Flaked (1.0 SRM) Grain 6.78 %
0.75 lb Chocolate Malt (450.0 SRM) Grain 5.08 %
0.75 lb Roasted Barley (300.0 SRM) Grain 5.08 %
0.75 lb Victory Malt (25.0 SRM) Grain 5.08 %
0.50 lb Caramel/Crystal Malt - 80L (80.0 SRM) Grain 3.39 %
I recorded a 4.6 with 1 tsp CaCl and 1/4 tsp of Lime per five gallons on this mash according to my notes. That is the lowest one I could find and it was for a stout.
So now I think I need to test with the R/O water to see where the base malt comes in with that.
I did use some little plastic cups to hold the buffer solution this time rather than the little jars that I usually use. Perhaps the other jars may be contaminated for some reason. I don't think so, but not sure what else could be a factor.
Neither terribly surprising. I've never checked the Rahr but your MO number is, while 0.05 higher than what I got, not too surprising.
I wouldn't expect much difference unless there is something really weird about the RO machine and I mean really weird such as they cleaned the membranes with acid and didn't flush them.
That is a distinct possibility. When you measure pH you compare the electrical response of your electrode in the sample to the electrical response in the buffer. If the buffer labeled 7 really has a pH of 6 but the meter thinks it is 7 it will think the electrical response from something really at pH 5 is at pH 4. It's really more complicated than that but I hope you get the idea.
That's possible and certainly anything you pour the buffer into should be clean but more important is that the used buffer not be put back into the stock bottle.
DSmith
Well-Known Member
Was your 5.7ph the Rahr "2-Row Pale" or "Pale Ale Malt"?
MachineShopBrewing
Well-Known Member
It was the 2-row pale.
