"What the pH....?"

[Brooothru]

I’ve always been a fan of Palmer’s “How to Brew” and accordingly target my grains and water chemistry to achieve a pH of 5.1 to 5.5. Lately there’s been a thread about targeting 5.6 to 5.8 pH, the theory being that it results in a ‘juicier’ and ‘hazier’ finished beer. But what happens when you end up going in the opposite direction?

The reason I ask is because of a brew session I had yesterday where everything went exceedingly well except for one thing: I couldn’t achieve my target pH. Not even close. My normal method is to target around pH 5.6 and adjust downward if necessary to reach 5.2~5.4 with lactic acid after the mash has had about 10-15 minutes after dough-in. Yesterday’s brew was a West Coast IPA from a recipe I’ve done many times before. The only changes were a new hop combo (Simcoe, Galaxy, Lemondrop) and the use of 50%/50% R.O water and tap water from our deep well. The water profile was for “light colored, hoppy” from the Brewer’s Friend advanced water calculator that I’ve used for years with great success. I even corrected for the additional Na and SO4 that I pick up from using Trifecta in the mash and in the final :10 minutes of boil. I’m just slightly OCD about my additions, attempting to keep them to a minimum, working the numbers twice, and always verifying my math and measurements. I generally hit my numbers.

So yesterday, ten minutes into the mash, I take a small (10 ml) sample, cool it to calibration temperature and stick the pH meter probe into the jar. pH 4.5! “What the pH….?” Can’t be THAT far off. So I decide to clean and recalibrate the meter. Rinse, dip in cleaning solution, perform a two point calibration using pH 4.01 and 7.01 buffers. Clean and rinse the sample jar. Obtain and chill the new sample. pH 4.4!!! Now I’m getting concerned. I’m nearly :30 minutes into a :90 minute step mash. First time ever I’ve found myself in this position. Normally I’d be adding one or three ml of lactic to bring it down, but how do I increase the mash pH to become more alkaline? And how much do I add?

That’s when I had a ‘senior moment’ and drew complete blanks. I figured taking no action was preferable to taking bad action, so I let ‘er ride. By the time everything was said and done and the fat lady was singing (post boil, post chill) my target of 1.059 OG was 1.058, my target volume was about 2 liters off, and the pH of the wort was down to 4.3. I transferred the wort into a sealed conical and chilled to 45F where it currently sits. I’m at a loss as to what I should do. Can I buffer the acidity before pitching the yeast? If so, what buffering agent and how much? Should I just roll the dice and pitch, hoping for the best?

I tasted the wort before pumping into the conical and it was a bit tart, rather than sweet. The hop aroma was very strong, though there were 3 ounces of late hops and 4 ounces in the hop stand, so there’s that. The only other time I’ve fermented a wort this acidic was one that finished around 4.9 and it was pretty bitter. I don’t want to give up on this batch before it even gets started, so if there’s something that I can do to mitigate the damage please advise. Thanks in advance.

Brooo Brother

 

[cswis86]

The pH of finished beer is around 4.0-4.5 so I wouldn't try to adjust it with anything now. The yeast should work just fine at that pH so I say just roll with it. Chances are it'll be fine though maybe not exactly like you intended. To adjust for low pH I add baking soda. Add about 1/2 teaspoon and check the pH again. Continue adding 1/2 teaspoon until you get to your target pH.

 

[Brooothru]

The pH of finished beer is around 4.0-4.5 so I wouldn't try to adjust it with anything now. The yeast should work just fine at that pH so I say just roll with it. Chances are it'll be fine though maybe not exactly like you intended. To adjust for low pH I add baking soda. Add about 1/2 teaspoon and check the pH again. Continue adding 1/2 teaspoon until you get to your target pH.

Thanks for the reply. I thought awhile about adding either baking soda or chalk but decided not to. My concern with baking soda was possibly raising Na levels too high. With chalk the concern was lack of solubility or increased calcium.

I did find an article in an old BYO magazine about pH that stated exactly what you said about "finished" beer pH being in the low 4s, and some ales in the high 3s (sours neat or at pH 3.0).
But mine was unfermented wort, so I wasn't sure what to do. I went ahead and cold pitched 2L of krausening starter last night (Wyeast 1217 West Coast Ale) at 63F, so it'll take a day or so to show much activity. I should have a good idea as to how this beer might turn out by next week. Fingers crossed.

Brooo Brother

 

[IslandLizard]

the use of 50%/50% R.O water and tap water from our deep well.

What kind of water did you use before?

 

[cswis86]

Thanks for the reply. I thought awhile about adding either baking soda or chalk but decided not to. My concern with baking soda was possibly raising Na levels too high. With chalk the concern was lack of solubility or increased calcium.

I did find an article in an old BYO magazine about pH that stated exactly what you said about "finished" beer pH being in the low 4s, and some ales in the high 3s (sours neat or at pH 3.0).
But mine was unfermented wort, so I wasn't sure what to do. I went ahead and cold pitched 2L of krausening starter last night (Wyeast 1217 West Coast Ale) at 63F, so it'll take a day or so to show much activity. I should have a good idea as to how this beer might turn out by next week. Fingers crossed.

Brooo Brother

I've made a couple kettle sours where the unfermented wort pH started below 4 and finished around 3.5. So I think your final pH will still end up falling in the normal finished beer pH and taste fine. I'm with you about the increase in Na from the baking soda but it's the easiest to adjust with during the mash. If you only have to add a little bit it probably won't make a noticeable difference.

 

[cswis86]

Here's an brulosophy experiment on low mash pH. Really the only measurable difference was that the final gravity was a bit higher because there is less starch conversion at a lower pH.

http://brulosophy.com/2017/01/30/wa...he-impact-of-low-mash-ph-exbeeriment-results/

 

[Brooothru]

What kind of water did you use before?

For IPAs and Pales I used well water corrected to style with minimal salts and minerals. For lagers and Continental beers I use either distilled (hard to come by these days) or R.O. adjusted with minimal chemistry as well. There's nothing in my water report to explain excess acidity. Ward Labs analysis was pH 6.9, which was what I measured as well two days ago with my pH meter.

There is one possible culprit that I don't want to consider. I recently restocked my specialty grains from a "widely acknowledged" mail-order HBS. Included in the order were 2# carapils and 2# acidulated, both 2°L. You don't suppose that in the hectic environment of filling so many orders that the two items got mis-marked? In this recipe I use 1/2 # carapils. Hmm.

Brooo Brother

 

[IslandLizard]

Included in the order were 2# carapils and 2# acidulated, both 2°L. You don't suppose that in the hectic environment of filling so many orders that the two items got mis-marked? In this recipe I use 1/2 # carapils. Hmm.

You're catching onto something...

Carapils (and Carafoam) is hard as a rock, you'd about break your teeth trying to chew it.

Acidulated malt is a base malt, chewable as such, and definitely tastes sour. If you'd pulverize 1/2 oz and mix with some water the pH will be well below 5.0, probably in the 3.3-3.7 region.

 

[Brooothru]

You're catching onto something...

Carapils (and Carafoam) is hard as a rock, you'd about break your teeth trying to chew it.

Acidulated malt is a base malt, chewable as such, and definitely tastes sour. If you'd pulverize 1/2 oz and mix with some water the pH will be well below 5.0, probably in the 3.3-3.7 region.

I'll do a taste/texture test and report back. All the various grains were individually bagged and labeled. It's conceivable that a harried or distracted worker, going down an order list of 10 or so items, 'forgot' whether the item just bagged and tagged was one or the other. Eight oz of acidulated (and the absence of carapils) could drive the pH down from mid-5s to upper-4s on a 12# grist bill. FWIW there were no acid additions nor dark roasted grains in this mash, so it increasingly looks like there might be a mix-up of grains.

Brooo Brother

 

[Brooothru]

I'll do a taste/texture test and report back. All the various grains were individually bagged and labeled. It's conceivable that a harried or distracted worker, going down an order list of 10 or so items, 'forgot' whether the item just bagged and tagged was one or the other. Eight oz of acidulated (and the absence of carapils) could drive the pH down from mid-5s to upper-4s on a 12# grist bill. FWIW there were no acid additions nor dark roasted grains in this mash, so it increasingly looks like there might be a mix-up of grains.

Brooo Brother

So, I did separate out two small samples of grain from the carapils and acidulated bags. I didn't even have to mini-mash them to check pH. It was very clearly obvious from taste which one was the acidulated (quite sour!). Oddly, it was from the bag marked "acidulated". The bags were properly marked. If the error was subbing acid malt for carapils, then the error is mine.

Nevertheless, after three days the fermenter is happily bubbling away and the gravity has dropped from 1.058 OG to 1.018 SG as of this morning. I didn't check the pH since the presence of yeast and other solids would probably skew any valid measure. The sample had a very intense but pleasant aroma, though a bit tart on the tongue. That will hopefully become subdued with time and conditioning.

Bottom line takeaways: the low pH readings on brew day were most likely accurate, don't know what caused it, probably was my fault (just don't know what or why), at the end of the day it'll still be BEER! And that's a good thing.

Brooo Brother

 

[dpeters]

I recently had a similar experience and did calibrate my PH meter. I found out my PH probe was shot I would take a ph of say RO water then my well water then some 5% vinegar and then if you went back and re-did them they would change and it was never consistent and read way lower than it should have. My two beers that read low turned out perfectly fine.

 

[Brooothru]

I recently had a similar experience and did calibrate my PH meter. I found out my PH probe was shot I would take a ph of say RO water then my well water then some 5% vinegar and then if you went back and re-did them they would change and it was never consistent and read way lower than it should have. My two beers that read low turned out perfectly fine.

I had the same concern about my probe, but my well water (pH 6.9, per Ward Labs) tested at 6.9 the same day as my brew day, so I think the probe is still functioning properly. I was recently reminded in a different thread that R.O. pH readings are pretty much meaningless since there are insufficient buffers in the water. Same for distilled water. Anyway, after two-point calibration with 7.01 and 4.01 buffer solutions, and after 'storing' the recalibration, the meter registered 7.0 in the 7.01 buffer and 4.0 in the 4.01 buffer. I'm pretty sure my wort readings on brew day were correct, and I'm hoping that the beer will end up good. I've only brewed lagers, light lagers and Continental lagers since last October, so I'm just now getting back into IPAs and ales. Time for a lupulin shift.

Brooo Brother