So I recently started looking into measuring and adjusting my final beer ph for my beers. I took a couple readings for a couple pale ales that were from a split batch and they were both very high around 5.5. I found that very odd but it was only one batch so I lowered them down to around 4.5 with lactic acid (which improved the flavor a good bit) and decided to get more data on my next brew. So a few weeks ago I brewed a black IPA and made sure to mmeasure my post boil ph which came out at 4.86. Well it’s now kegged and I took a non carbonated room temp sample and it was up around 5.5 again. What I want to know is what is causing this? The only thing I can think of is a wild yeast infection, but it still doesn’t make sense to me that fermentation is raising my ph rather than lowering it.
That is a stumper. Any acid producing bug would lower the final pH even more. I suspect the probably is instrumentation.
Describe how you are doing the test.
That seems odd to me too. My first thought would be the quality/condition/calibration of your pH meter.
My post boil pH is usually in the 5.1 range… and it always drops to 4.5ish or lower during fermentation.
I have never had a beer go up in pH … not sure if that is possible without adding something? Topping off with hard water… I don’t know. Just can’t think of how the pH wouldn’t go down during fermentation.
What are you using for a pH meter and how certain are you that it is correctly calibrated?
I you could describe your calibration procedure in detail something might emerge. Like the others, I suspect that the beer pH is not as high as you measure. Perhaps you could test a snpa or something?
Great idea. SNPA should be in the neighborhood of 4.3 degassed and room temp
I have a Milwaukee 102 meter. I too thought it might be off when I got the first high reading with my pale ales so I recalibrate it. It changed a little but not much and was still way up there. I use ph 4 and 7 solutions I bought on amazon and follow the instructions for the meter. I know it’s accurate because I just hit my mash ph for a german lager I brewed last week. Also I’m all grain so no topping off. The only thread I was able to find online with a similar problem the guy determined it was a wild yeast/infection problem. My numbers are still higher than his though. I was thinking since I use star San and not something like iodophor I could have the same thing. Never had a visibly infected batch though or one that fermented out way too much.
Try testing about any commercial beer using the same method you use for test your beer. Pretty much any commercial beer should be at or below 4.5ph. If it comes in at 5.5 you have an issue.
What do you do for yeast? How long does the beer sit on the yeast before these measurements? Yeast autolysis will raise the beer ph. Not sure how much but it does…if you are having yeast problems that could be something. Just throwing out the only thing I can think of.
I usually primary for around 2-4 weeks so I don’t think auto lysisIis the issue.
I’ll test a beer when I get a chance to be sure my ph meter isn’t the problem but either way it went up according to the same meter
Thoroughly rinsing the probe with DI or the like between buffers and between them and the test solution? How large of a volume are you testing? No chance of any detergent or soap residue on the measurement vessels? How old are the buffers and how long have they been open?
You don’t mention it, but I’m assuming that you “degass” the beer samples prior to measuring the pH.
How’s the beer taste?
I usually get 2 cups of the buffer solutions and rinse it in the buffer before using the 2nd cup for calibration. Shouldn’t be any soap residue. They’ve probably been open anywhere from a month to six months and are less than a year old.
This is why I started testing in the first place, I haven’t been very happy with my hoppy beers at all. They always taste muddled or just bitter without that juicy hop character I’m aiming for. My pale ales tasted much more crisp and refined with actual layered hop flavor when I lowered the pH down to 4.5 or so. I would just rather find what’s going on so I don’t have to dump a bunch of acid in my beer every time. I measured the pH of a vanilla coffee porter I had as well which was around 4.8. I tried lowering it with acid in a glass just to see the results and I did not like it at all. This makes sense to me as I’ve been much more pleased with my dark beers. So another question is what’s the difference between my pale hoppy beers and my darker beers that for my porter ph was below 5? I suppose one answer could be I added coffee to the secondary.
How are you treating your water? I had a very similar problem to yours until I had my brewing water analyzed and realized it sucked. My hoppy beers never popped or came through at all until I made sure my mash water had a sulfate to chloride ratio of 2:1
I use RO water from a system I installed recently and then build up from there
So the results are in. I tested the 4.00 calibration buffer, a degassed coors light, my black IPA degassed, and a pilsner I brewed degassed:
Calibration buffer = 4.05 (not perfect, but accurate enough for these purposes)
Coors light = 4.11
Black IPA = 5.55
Pilsner = 4.36
These results just confuse me even more and I have no idea what to make of them. I’m starting to think about the fermenters that I used for each beer. The pale ales were fermented in a couple of my better bottles, the IPA in a 10 gal corny keg I just recently acquired, and the Pilsner in my 6 gal glass carboy. I’m starting to question my better bottles because when I first started brewing I left PBW in them and let them sit outside for a very, very long time (months). The 10 gal corny keg, which was not in great condition when I got it, I cleaned as thoroughly as I could but maybe it was not good enough. I can’t think of any reason my glass carboy would give me any problems, and that ph seems to be right where it should be. Is there anything potentially in these fermenters that could have caused the spike in ph?
I could definitely see PBW crust/film raising your pH. I’m confused - what beer are you referring to with “pale ales,” the ones fermented in better bottles?
Yes - the ones in the better bottles that I mentioned in my original post. They were the first beers I tested (it was a split batch) and found my beer ph was that high.
But the beer (IPA) fermented in the corny also showed the effect, right?