Final beer PH too low

[Eamonn]

Thanks AJ will double check my meter readings. I've been pretty careful but you never know. I bought new buffers recently and store the electrode in storage solution. Following this ill try to get it under a microscope, just need to find someone that can do it. Otherwise White labs has a service so I might post a sample to them.

[Eamonn]

What you describe does indeed sound like a classic problem of infection by an acid producing bacterium but there should be other signs of that i.e. turbidity and the beer should taste sour. You do not report that it does. So you have a beer with a pH of 3.8 that doesn't taste sour. This makes me question your pH readings. Have a look at the post at http://www.homebrewtalk.com/f128/my-hou ... ndex2.html. I listed all the steps necessary to properly calibrate and use a pH meter. Make sure you are doing all that stuff correctly. I've seen people post complaining about low pH readings (funny, it's always too low - never too high) only to find out they are still calibrating with the same buffers that came with the meter when they bought it a year ago. I'm not suggesting that you are doing anything like that but what you are seeing is weird and every possibility needs to be checked to get to the bottom of it.

Another possibiity for funny pH meter readings is meter drift. Try calibrating, then measuring the pH of the two buffers with the newly calibrated meter. It had beter read close to 4 and 7. I had one fellow recently report that when he did this the first buffer measured (whether it was the 4 or 7) read off by 0.5 pH during such a subsequent check. This is, obviously, indicative of a faulty meter or electrode. If you pass this check try reading the 4 buffer just after taking the suspiciously low reading on the beer. If the beer reads 3.8 and the buffer reads 4 then that's a pretty good indication that the meter is properly calibrated.

Another thing to try is borrowing a friend's pH meter or taking one of the low pH sample to his house and checking the pH with another meter.

If any or all of this verifies that the pH's are indeed that low then you must look to your fermentations. I'd start by looking at the beer under a microscope.

AJ - I've checked my meter and I'm sure its calibrated. Its also quite new and a good meter (Milwaukee MW102 and I store the probe in storage solution). Furthermore the commerical beers I measured come in on my meter where I expected (4.2-4.3 for ales, 4.4 -4.5 lagers). My problem is very consistent. And as you've mentioned no turbidity, or bacterial sourness. I'll get it under a microscope (as you have suggested) to be sure, any idea what a lactic infection would look like under a scope?

I'm also looking at potential low ph buffer capacity in my beer causing the ferment to push the ph so low, and perhaps a mash related reason for this (something unusual I am doing that I may not realise). Maybe I am losing all my calcium in the mash and in spent grains.

I post by SBradt on
http://www.probrewer.com/vbulletin/show ... 069&page=2
indicates a similar problem, that was solved by adding calcium in the brew kettle (instead of just mash) to provide a buffer to PH drop. I may try this next (I only add salts to mash). Also, the Kaiser has some interesting comments in the following thread:
http://www.homebrewersassociation.org/f ... 75.20;wap2
Various acidification techniques, and how the amount of calcium can affect the final beer ph regardless of mash ph. I also remember my dark beers having a ph above 4 which aligns with Kai's comments about lightly kilned malt being more susceptable to the phosphate activity.

I feel like I am getting closer (I hope)- thanks for the tips.

[bufordsbest]

I am currently having a similar issue to this with all my darker beers. A lot of my pale beers are ipa/apa and come out pretty good although they are hop dominated and it's hard to pick out malt character. I've brewed several dark beers over the last year from brown ales to stouts and they all come out with a similar "plain old beer" aroma and absolutely zero flavor. if you were to close your eyes you wouldn't be able to pick out my oatmeal brown ale from a coors light.

i thought originally it must be lack of attention to mash ph. (i had a crappy meter) My last brew was a brown ale and with my new milwaukee ph meter (freshly calibrated) had a mash ph of 5.5. (taken at room temp) i just tasted the beer today and nothing, zero flavor or aroma. i will check the finished ph of the beer and check to see if it is too low like you are experiencing.

i currently use tap water with salts added to help hit target mash ph but back when i first started to brew all-grain i had a lot of nice dark beers turn out using nestle purelife bottled water which has a high mineral content and is fairly alkaline. i tried going back to this water on an amber ale to see if the water was the culprit but although better the beer was still fairly bland.

it's an incredibly frustrating issue since it really doesn't seem like a common problem.

[bufordsbest]

ok so i just calibrated my ph meter and took readings on 2 beers i currently have in my kegerator.

an apa measured at 4.52, a brown ale 4.56 and a coors light at 4.10.

not sure what i will do next.

[Eamonn]

ok so i just calibrated my ph meter and took readings on 2 beers i currently have in my kegerator.

an apa measured at 4.52, a brown ale 4.56 and a coors light at 4.10.

not sure what i will do next.

For an APA and a brown ale, pH = 4.5+ is a little too high. THis could explain the dull flavours you are experiencing. If you measure commerical pale ales you will find they are around 4.2-4.3. Lagers are usually a touch higher- I've measured a few german ones at around 4.4. See if you are pitching enough yeast, and that your fermentation is healthy. And that you have sufficient calcium in your mash and wort. I've done a fair bit of research on this - a specific mash pH doesnt guarantee a specific final beer pH. It depends on the buffers present in the wort and many factors come into play - temperature, yeast health, nutrients, wort FAN levels....

[Eamonn]

Time to bump this and hope a brewing scientist can offer some advice....

My beers are still finishing pH=3.65-4. I sent a sample of an extract pale ale (pH=3.84) and all grain dark ale (pH=3.95) to a lab in England (while I was there). Results:

SAMPLE WLD/LYS RAKA – RAY
3614 Dark
Nil growth Nil growth
3615 Light
Nil growth Nil growth

So if there is an infection it would be a wort spoiler that is killed during the pH drop during fermentation. I use a totally different set of equipment for extract than all-grain, but problem persists regardless. So its got me almost beaten. I'm now suspecting the starsan (im probably losing my mind).

Does anyone know a wort spoiler, water contaminant or mechanical issue, that can destroy the buffering ability of the wort???? I'm thinking obesumbacterium proteus (wort spoiler) might be capable, but all my reading cannot confirm it. The latest beer I brewed was with a belgian yeast starter. Starter beer tasted pretty good, pH of it was about 4.13. Beer came out at 3.65 after a post boil pH of 5.4 @ 20C. Beer even had a whiff of belgian yeast character despite being so low in pH. I've been researching pretty hard for 6 months and still can't come up with anything. My pH control during mashing is near on perfect, and I've had the same problem with extract beers anyway (with RO water).

This is driving me crazy! Bamforth has discussed it on Brew Strong (30-11-09), but it doesn't give any idea what can put a beer below the acceptable range (below pH=4). All I can find in brewing science texts is that factors affecting fermentation vigor (yeast, temperature, nutrients, FAN etc). I seem to be doing nothing unusual there and have tweaked several of these items to see if there was an effect. I've also find plenty of info on wort spoilers, but nothing specific about any of them dropping beer pH quite rapidly. Actually the texts often say that the pH ends up a bit high in the beer.

[beerhog]

Time to bump this and hope a brewing scientist can offer some advice....

My beers are still finishing pH=3.65-4. I sent a sample of an extract pale ale (pH=3.84) and all grain dark ale (pH=3.95) to a lab in England (while I was there). Results:

SAMPLE WLD/LYS RAKA – RAY
3614 Dark
Nil growth Nil growth
3615 Light
Nil growth Nil growth

So if there is an infection it would be a wort spoiler that is killed during the pH drop during fermentation. I use a totally different set of equipment for extract than all-grain, but problem persists regardless. So its got me almost beaten. I'm now suspecting the starsan (im probably losing my mind).

Does anyone know a wort spoiler, water contaminant or mechanical issue, that can destroy the buffering ability of the wort???? I'm thinking obesumbacterium proteus (wort spoiler) might be capable, but all my reading cannot confirm it. The latest beer I brewed was with a belgian yeast starter. Starter beer tasted pretty good, pH of it was about 4.13. Beer came out at 3.65 after a post boil pH of 5.4 @ 20C. Beer even had a whiff of belgian yeast character despite being so low in pH. I've been researching pretty hard for 6 months and still can't come up with anything. My pH control during mashing is near on perfect, and I've had the same problem with extract beers anyway (with RO water).

This is driving me crazy! Bamforth has discussed it on Brew Strong (30-11-09), but it doesn't give any idea what can put a beer below the acceptable range (below pH=4). All I can find in brewing science texts is that factors affecting fermentation vigor (yeast, temperature, nutrients, FAN etc). I seem to be doing nothing unusual there and have tweaked several of these items to see if there was an effect. I've also find plenty of info on wort spoilers, but nothing specific about any of them dropping beer pH quite rapidly. Actually the texts often say that the pH ends up a bit high in the beer.

have you tried switching sanitizers? i have had an infection that persisted for three or four batches when i was using starsan and only went away when i went to using iodophor instead. it seemed to me that a bug had grown an imunity to the starsan so now i like to change my sanitizer every three or four batches just to ensure it never happens again, it is heart breaking after all the work that goes into a batch to have to tip it out, let alone a persistant problem like youre dealing with. i really hope you can get on top of it soon.

[ajdelange]

This is indeed a mystery. You asked in a previous post what an infected beer would look like under a microscope. The answer depends on what the infecting organism is. You should be able to find some pictures on the web of the various typical problem organisms. Basically, if you see anything that doesn't look like yeast then it doesn't belong in the beer. Lacto's look like like tiny pieces of thread about as long or longer than a yeast cell, Pedio's look like little pairs of dots much smaller than yeast cells. The only thing that may be confusing is protein globules which may be mistaken for bacteria at first. If the beer is clear then it is unlikely that you will find bacteria.

Another note from the later discussion: calcium does not impart any buffering capacity. What sets the pH of finished beer, AFAIK, is the yeast. In a healthy ferment they secrete acids until the pH is where they like it so, while getting the calcium level proper for yeast may reneder them better able to control pH the calcium itself does not hold pH up.