Mash pH

[rideincircles]

I measured my Russian Imperial Stout Mash PH at 4.18 yesterday. It had 19 lbs of British 2-row and 4 lbs of specialty malts. Would there be any normal reason it would be this low. I have not calibrated my PH meter, but it is the red/black one. Normally Fort Worth brewing water is fine. I don't have a charcoal filter.

Normally I haven't paid much attention to the mash ph, but this seemed really low. I did add potasssium metabisulfite to the water before boiling, and I recall that some of the water I had boiling left a lot of white residue at the rim that had boiled down.

I made a run off porter batch that ended up with 3 gallons at 1.040 and it was really astringent. Would this be caused by the low ph? My mash was at 154 pretty much the whole way and I sparged with 170-172 degree water and the porter was pretty much all 170 sparge water.

Also, I just checked my tap water and it measures at 7.3. I checked by adding a few pinches of metabisulfite and it dropped to 5.8. I think that may be the reason, but I did not add a huge amount, although I didn't measure it specifically.

 

[ajdelange]

I measured my Russian Imperial Stout Mash PH at 4.18 yesterday. It had 19 lbs of British 2-row and 4 lbs of specialty malts. Would there be any normal reason it would be this low.

Defective pH meter or one that was way out of calibration.

I have not calibrated my PH meter, but it is the red/black one.

Not sure what the relevance of the color of the meter is. If it hasn't been calibrated in a long time it is virtually useless or perhaps worse than useless as it may cause you to draw erroneous conclusions regarding correction.

Normally I haven't paid much attention to the mash ph, but this seemed really low.

It is. Even if you added 4 pounds of sauermalz to 19 pounds of a typical base malt you wouldn't get to pH 4.18.

I did add potasssium metabisulfite to the water before boiling,

I assume this means you added a couple of tenths of a gram or so for chloramine control.

Would this be caused by the low ph?

Unless you added a lot of acid to your water you never got near pH 4.18 so I'll say no.

Also, I just checked my tap water and it measures at 7.3. I checked by adding a few pinches of metabisulfite and it dropped to 5.8. I think that may be the reason, but I did not add a huge amount, although I didn't measure it specifically.

Metabite is acidic (it releases sulfurous acid) but you'd have to add grams of it to a few gal of water to get anywhere near pH 4. If you did do that I can't begin to predict what the results might be beyond pretty bad beer.

 

[rideincircles]

Cool. Thanks. I am still not sure as to why my measurement seemed so low, but the dark malts were near the top of the mash tun while the regular grain was mostly at the bottom. THat may have affected the number I got. I did not check it again.

Fermentation has now started on my stout. As far as the run off batch, I assume I may have started pulling some tannins or something along the lines out of the mash. The stout didn't seem to have the problem. I will now wait for months for the final results.

 

[ajdelange]

Dark malts will not give a pH as low as 4.18. In case you missed the point, an uncalibrated pH meter is worthless.

 

[roncruiser]

One of the better threads I've come across on mash PH. Not hundreds of replies long. No noise. Solid precise information. An excellent read.

 

[gifty74]

Well, I wrote John an email a few hours ago and this is what I got back:

"Jeff, those are a target for hot side.

John Kimmich

By "hot side" are you sure he's not referring to the boil kettle (often referred to as the hot side) and not that the pH is measured hot (i.e. At mash temps)??

 

[PlinyTheMiddleAged]

Well, given the pH ranges that he mentions in his talk, I'd say those are at mash temps. But since he didn't say mash temps, I can't be certain. Brew the same beer at two different pH and let us know what you think.

 

[gifty74]

Agreed. Right before that he says "I cannot stress enough the importance of treating your mash water." So ok, he's definitely talking mash pH.

What's more odd is he says "if you are not hitting between 5.1 & 5.3 you're at a disadvantage. If you're over 5.3, you're at a serious disadvantage. If you come in under it's much more forgiving. You can have an acidic mash, and still have a beautiful bright crisp nice beer at the end. If you're up in that 5.4, 5.5 5.6...forget it, it's going to be a muddled piece of sh*t."

Pretty interesting, when the common target for an IPA seems to be a consensus 5.4 on this forum. But, if he's talking in terms of those pH's measured "hot", we should be adding 0.3 units as we are mostly talking in terms of room temp mash pH's.

 

[rhys333]

I brewed a Rye Saison yesterday with the grist info and mineral additions shown below. I estimated room-temp mash pH using three different calculators: Bru'n = 5.37, Brewers Friend = 5.57, EZ = 5.59. I went with Bru'n on this one and I'm interested to see how it turns out due to variance of ~0.2 pH value. I observed fast and efficient mash conversion. Also achieved better than expected brewhouse efficiency at 76%. Due to rye inclusion and dunk sparge without squeezing I expected low 70s at best.

RYE SAISON
82% - 3.3 kg (7.3lb) 2 Row 1.75L
10% - 0.4 kg (0.88lb) Rye 3.5L
7% - 0.29 kg (0.64lb) Munich 12L
1% - 0.04 kg (0.09lb) Black Patent 525L

- Mash water: 11.36L (3 gal), Sparge 15.1L (4 gal).
- Used 100% RO (Ca:1; Na:8; SO4:1; Cl:4, bicarb:16) and treated ALL water at 0.18 g/L Gypsum + 0.13 g/L CaCl2. Also 0.5 ml 88% Lactic acid to mash only. Spreadsheets disagree on final mineral concentration, but Bru'n estimates Ca: 89; SO4: 100; Cl: 83.

This is my first time treating sparge water and going with the lower estimate (i.e.: adding less acid: 0.5ml instead of 2.7ml). All went well and it will be interesting to see how this turns out!

 

[Biscuits]

I am curious now about how no sparge BIAB'er are effected by this? I mean, by treating all of my liquor and targeting a mash pH of 5.4 (or whatever), typically the kettle pH will start out the same. Should the pH in the kettle then be adjusted? I have read through this thread and I am still not understanding what the target kettle pH should be and at what temperature.

 

[rhys333]

I am curious now about how no sparge BIAB'er are effected by this? I mean, by treating all of my liquor and targeting a mash pH of 5.4 (or whatever), typically the kettle pH will start out the same. Should the pH in the kettle then be adjusted? I have read through this thread and I am still not understanding what the target kettle pH should be and at what temperature.

Your mash pH is the critical measurement, 5.4 RT or there abouts. You're fine adding all the minerals to the mash as long as the estimated pH doesn't drop below the desired range. If it does, then you reserve a portion of the minerals and add to the kettle.

 

[gifty74]

Also 0.5 ml 88% Lactic acid to mash only.

Great feedback. So when did you check mash pH (how much time into it after dough-in), what temp was it when you took the reading, and how much did the .5ml of lactic reduce it?

I ask because I brewed a DIPA, and used 17g of gypsum for 10.5 gal of water. My water is relatively soft, so beersmith said my sulfates should be near 250, and Ca around 125 (chloride around 60). I have 85% phosphoric acid, and 5 mins after dough-in I checked pH and it was 5.7 at room temp. I added 2.5ml of my acid and only brought it down to 5.6 (this was probably 10-12 min into mash). Added another 2.5ml of acid, and brought it down too much. Room temp pH was around 5.3, was shooting for 5.4-5.5. BK pH was ok though at 5.4, so not sure how much of an impact the over addition of phosphoric acid will have, but hopefully not much. The grains also start to get soaked into solution and help buffer as well, so taking readings on the fly is helpful, but can lead to some misdirection as well, as was the case with my session. Next batch with similar malt bill I'll be adding 3.5ml of acid and it should be right at 5.5 at room temp (5.2 in the mash).

I did get an email back from John Kimmich (who's adamant about the 5.1-5.3 pH range at mash temps) and he said the best method is trial & error, and keep brewing a recipe over and over until you nail it. He said that it's important to get the pH right from the start as most conversion happens in the first 5 min and you want the pH to be 5.2 while that is happening.

Bottom line is I took great notes, and know the grain bill and my source water so I should be able to better tweak on this next batch.

Oh, and Kimmich also thinks food grade lactic acid is the best one to use for acidification. He said he hardens with gypsum and acidifies with lactic.

 

[rhys333]

Great feedback. So when did you check mash pH (how much time into it after dough-in), what temp was it when you took the reading, and how much did the .5ml of lactic reduce it?

I'm brewing without a safety line... no pH meter. My taste buds will provide the answers.

 

[Biscuits]

Your mash pH is the critical measurement, 5.4 RT or there abouts. You're fine adding all the minerals to the mash as long as the estimated pH doesn't drop below the desired range. If it does, then you reserve a portion of the minerals and add to the kettle.

I have a decent grasp on mash pH but what I am concerned with is kettle pH. Am I sane in reasoning that if my mash pH is in the acceptable range that my kettle pH will then too be acceptable? I am curious because where traditionally a brewer would get their mash pH in range and then sparge with water that is treated differently or not at all, that maybe treating all of my brewing liquor the same puts me at a disadvantage.

 

[gifty74]

I am curious because where traditionally a brewer would get their mash pH in range and then sparge with water that is treated differently or not at all, that maybe treating all of my brewing liquor the same puts me at a disadvantage.

Straight from my email from John Kimmich...

"You should be treating the entirety of you brew water before you mash in. Most of the starch conversion happens in the first 5 minutes, so it's important to nail it. Trial and error is best. Stick with one recipe until you nail it. Adding acid after the fact is not desirable for the reasons you mentioned. Food grade lactic is a much better option imo.

John Kimmich"

 

[rhys333]

I have a decent grasp on mash pH but what I am concerned with is kettle pH. Am I sane in reasoning that if my mash pH is in the acceptable range that my kettle pH will then too be acceptable? I am curious because where traditionally a brewer would get their mash pH in range and then sparge with water that is treated differently or not at all, that maybe treating all of my brewing liquor the same puts me at a disadvantage.

Why are you concerned with kettle pH? As long as mash pH has been figured out, the boil and fermentation process will take things from there to ensure the beer ends up in the desired pH range, which I understand is somewhere around 4.

 

[Biscuits]

Why are you concerned with kettle pH? As long as mash pH has been figured out, the boil and fermentation process will take things from there to ensure the beer ends up in the desired pH range, which I understand is somewhere around 4.

Because it seems to be of some concern to professional brewers...and considering the slight differences in homebrewing methods I thought there might be some effect from that. I don't like to just assume.

 

[rhys333]

Because it seems to be of some concern to professional brewers...and considering the slight differences in homebrewing methods I thought there might be some effect from that. I don't like to just assume.

I haven't noticed any issues, but valid concern. Perhaps one of the brew science specialists can advise.

 

[rhys333]

He said that it's important to get the pH right from the start as most conversion happens in the first 5 min and you want the pH to be 5.2 while that is happening.

Bottom line is I took great notes, and know the grain bill and my source water so I should be able to better tweak on this next batch.

I'm no expert, but that makes a lot of sense to me.

 

[SpeedYellow]

Straight from my email from John Kimmich...

"You should be treating the entirety of you brew water before you mash in. Most of the starch conversion happens in the first 5 minutes, so it's important to nail it. Trial and error is best. Stick with one recipe until you nail it. Adding acid after the fact is not desirable for the reasons you mentioned. Food grade lactic is a much better option imo.

John Kimmich"

What does starch conversion during the first 5 minutes have to do with beer flavor? Let's just assume that mash pH is super important for best flavor (however defined) -- but who's to say that the first 5 minutes matters? Let's say you botch initial pH but fix it at 10-minutes in. Is there *any* evidence you'll have a different beer than one where you nailed it at dough-in?

Sounds like he found a winning formula but is speculating as to what makes it a winner. Which we all do to some extent.

 

[gifty74]

What does starch conversion during the first 5 minutes have to do with beer flavor? Let's just assume that mash pH is super important for best flavor (however defined) -- but who's to say that the first 5 minutes matters? Let's say you botch initial pH but fix it at 10-minutes in. Is there *any* evidence you'll have a different beer than one where you nailed it at dough-in?

Sounds like he found a winning formula but is speculating as to what makes it a winner. Which we all do to some extent.

My guess is he is referring to it in relation to efficiency. Being a production brewery they I'm sure want it at 5.2 when the conversion happens, to maximize conversion. But on our scale, like you say, why would it matter?

And I'm also thinking that by now he would know what makes it the winning formula it is, and what makes it not.

 

[rhys333]

What does starch conversion during the first 5 minutes have to do with beer flavor? Let's just assume that mash pH is super important for best flavor (however defined) -- but who's to say that the first 5 minutes matters? Let's say you botch initial pH but fix it at 10-minutes in. Is there *any* evidence you'll have a different beer than one where you nailed it at dough-in?

Sounds like he found a winning formula but is speculating as to what makes it a winner. Which we all do to some extent.

I don't know if its 5, 10 or 15 minutes, but I think it's reasonable to assume that if pH is too high, tannin extraction will start a short time after the water hits the grain. I've always believed that if the pH is out of whack to begin with, then testing it at 15-20 minutes and then spending another few minutes correcting the pH is like closing the stable door after the horse has bolted. It's still great information thought because it lets you make adjustments the next time you brew the same recipe (or other ones if you pH tends to be off by a predictable amount).

 

[SpeedYellow]

...I've always believed that if the pH is out of whack to begin with, then testing it at 15-20 minutes and then spending another few minutes correcting the pH is like closing the stable door after the horse has bolted..

That's my operating assumption too, but I recognize it's total speculation. It could be completely wrong, and would be fairly easy to test.

And I'm only referring to the impact on flavor, since I care not a whit about efficiency.

 

[masonsjax]

If certain enzymes are more efficiently breaking down complex carbohydrates at a particular pH, I would say yes, that could affect the flavor. It's not like you can reverse enzymatic activity and put the unfermentables back in. With these ultra modified malts we get these days, it may be a matter of seconds to get it right rather than minutes even.

 

[mabrungard]

Recognize that "mash temp" was mentioned the brewer's recommendation. That is generally in line with a recommendation of 5.3 to 5.5 when measured at room temp. However, for those of us that like their equipment to last longer, measuring at room temp is smarter.

 

[rhys333]

I brewed a Rye Saison yesterday with the grist info and mineral additions shown below. I estimated room-temp mash pH using three different calculators: Bru'n = 5.37, Brewers Friend = 5.57, EZ = 5.59. I went with Bru'n on this one and I'm interested to see how it turns out due to variance of ~0.2 pH value. I observed fast and efficient mash conversion. Also achieved better than expected brewhouse efficiency at 76%. Due to rye inclusion and dunk sparge without squeezing I expected low 70s at best.

RYE SAISON
82% - 3.3 kg (7.3lb) 2 Row 1.75L
10% - 0.4 kg (0.88lb) Rye 3.5L
7% - 0.29 kg (0.64lb) Munich 12L
1% - 0.04 kg (0.09lb) Black Patent 525L

- Mash water: 11.36L (3 gal), Sparge 15.1L (4 gal).
- Used 100% RO (Ca:1; Na:8; SO4:1; Cl:4, bicarb:16) and treated ALL water at 0.18 g/L Gypsum + 0.13 g/L CaCl2. Also 0.5 ml 88% Lactic acid to mash only. Spreadsheets disagree on final mineral concentration, but Bru'n estimates Ca: 89; SO4: 100; Cl: 83.

This is my first time treating sparge water and going with the lower estimate (i.e.: adding less acid: 0.5ml instead of 2.7ml). All went well and it will be interesting to see how this turns out!

Further on my post above...
Tasted the gravity sample after 6 days in primary. Hot yet, but otherwise clean and zero astringency. This is interesting. Usually I treat mash water only and sparge with straight RO. Because I added lower than normal amount of acid, prior experience had me expecting harsh astringency. I suspect treating sparge water has made the difference. Anyway, looking good so far and I look forward to tasting it again after conditioning.