Final beer PH too low

[pkrid]

Eamonn

Try switching to spring water and see if that helps.

I was using untreated RO water when I switched to all grain and it made an instant difference in my beer. I also improved my process at the same time thanks to the BN but the water made the fastest improvement.

[Eamonn]

I think I've worked it out - I have been adjusting for ph = 5.2 to 5.4 at room temp instead of mash temp, and more so at the low end of this (5.2). I have been doing this for a long time and wondered why my beers have had no flavour and thinned out once carbonated. Taking the ~0.25 correction factor and my mash ph at mash temp has been far too low (4.95-5.15). THis has got to be why my final beers are getting to ph 4 and below! I had just assumed the widely quoted 5.2 to 5.4 had always meant at room temp ! Generally because calibration is at room temp.

I'm such an idiot ! But I have learnt a lot looking at every conceivable thing that may be wrong my beer.

[craigevo]

Its in Noonan's Lager book.

pH drops lower for ale yeast compared to lager yeast. There was some techno babble about why this is but it was beyond me.

So that would lead me to wonder if its an absolute or relative drop from post boil pH. And if you are making, say, a stout or porter that would drop to a low mash pH, could you 'make up for it' by fermenting with a lager yeast ! Could this be why some people prefer these styles when they use lager yeast. Maybe they dont measure their pH and just end up correcting the problem of low mash pH by the side effect of using a lager yeast. hmm crazy theory i guess. my brain hurts now.

[Eamonn]

I'm giving this a bump as I am the OP and I have an update (problem: final beer ph too low)

I've effectively ruled out all my equipment up until the cold side.
Despite oven cooking my therminator on every batch and circulating the boil through it, I decided to no-chill a batch to rule out the chiller. The no-chill wort was 5.55 @ 25C mash, and 5.51 at pitching after 24 hours in the cube. Wort seemed sterile.

I took a sample at high krausen (48 hours) and ph was 3.98 (at gravity of 1030 when OG was 1042). What the!!!!! This was a rehydrated US05, but I get the same result regardless of my yeast strain. Chiller ruled out. To add insult to injury I left some wort in a cup in my garage, and it started fermenting (wild yeast). After 24 hours, ph was 4.8, after 48hrs, it was 4.6. Hmm.

Does anyone know if this could be a lactic infection? There are no visual signs - the fermentation is very clean looking, and the resulting beers look perfect and clear up well. Decent head retention, kind of fresh smell, but just no malt or hop flavour, probably due to the super low PH. Doing some reading, there are things like Zymomonas which can survive in low ph conditions. But how do they get past the starsan? I just cannot understand how the ph can get this low - my mash mechanics are good. Either filtered tap diluted with RO, or 100% RO with light use of gypsum and CaCl2. Proper mash PH, etc. I have an well calibrated Milwaukee meter with 0.01 accuracy. Everything I read about lactic infections doesn't seem to reflect what I am experiencing, nor does it mention beer PH. I am not getting turbidity, sourness, or anything like that. I use starsan in my fermenters (I use glass or better bottle - no difference in result) at the correct concentration.

Next I am going to do some very small test batches with DME & RO - one in a 5L sterilised (boiled) erlenmyer, and the other in a starsan sanitised jar. I will measure the PH on each and see if I can rule out my brewing system completely. MAybe my bottle of starsan is faulty - unlikely, but one thing I have treated as a constant.

One point to add- I had a beer recently that finished at ph=4.14 (rare to get higher than 4). It was pretty good, despite the ph stil being lower than it should be (mash ph was 5.6 at 25C). But it wasnt as low as the others. This makes me think once this PH problem is sorted everything else will fall into place.

Anyway your help would be appreciated, because I need to sort this out, its driving me crazy - Well over a year of this very strange problem. I feel like my brewery is cursed.

[Blunt]

I would try doing a darker beer with untreated spring water for the mash. Let the darker malts adjust the ph for you and treat the sparge water as you have. I seem to remember you mainly do pale beers they seem to give me trouble getting the ph right to but I don't get as precise as you do I let it be a little higher than lower. Maybe the darker beers we at least give you a beer that the ph is on.

[Eamonn]

I would try doing a darker beer with untreated spring water for the mash. Let the darker malts adjust the ph for you and treat the sparge water as you have. I seem to remember you mainly do pale beers they seem to give me trouble getting the ph right to but I don't get as precise as you do I let it be a little higher than lower. Maybe the darker beers we at least give you a beer that the ph is on.

Blunt, acheiving my desired mash ph is not a problem, I have total control over that, regardless of beer colour. I aim for 5.5-5.6 at room temp (which is 5.2-5.3 at mash temp). Its the ph drop during fermentation that is out of control. Drops to 3.8-3.9 instead of 4.2-4.4. I've measured the ph of several commerical ales and they come in about 4.2-4.4. I wonder if there is anything I could be doing in the mash that set a precursor for the beer ph to drop so much. Or is is some kind of lactic infection that leaves no visual or sour traces.

[Blunt]

After reviewing your posts I saw two things that could possible have an impact.
One: your fermentation vessel glass or plastic or metal? Maybe try a new one
Two: same sanitizer, starsan? Maybe try a different one
Both cold side which you had mentioned and that seems to be where your at in the troubleshooting right. Anyway sounds like your on the right track good luck.

[ajdelange]

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.