Final beer PH too low

[HotCheese]

I'm having this same issue all my beers just taste extremely BLAND and lifeless with a common theme LOW FINAL PH 3.7~4.1

I've tried many different variables similar to the op:
- sanitation
- yeast type
- hop amounts
- attenuation levels and Mash temps
- aeration (pure co2)
- recipe formulation (simple recipe 2-3 malts max, big hop additions)
- water chemistry
- 100% R/O vs 100% Tap Water with carbon filter and campden tabs
- PH management (Mash PH/kettle PH/Fermentor PH) - target 5.4 for hoppy styles
- fermentation temp - (low end 64F and high end 69F)
- carbonation levels

I'm fully convinced at this point, I have some type of bacterial infection, wild yeast, and/or contamination that is getting past my PBW and Star San regimen.

[HotCheese]

I was able to capture evidence

Re-iterating the experiment description:
I sterilized 5 jars with their caps in a pot of boiling water for 15 minutes and then filled each jar with cooled DME that I made (just like a starter but without adding yeast.). I then poured the DME into each jar and a put one by the sink/washer where I cool my wort and one in the fermentation chamber where they sat open for 2 hours before I capped them. As for the other three, one was capped right away which was the control, one was aerated with a dry but un-sanitized aeration stone, and the last one was put on the stir plate for 24-36 hours.

Notes from Thursday before capping each one:
==============================
Control:
PH: 5.95
Brix: 11
Taste/Aroma: tasted and smelled like DME

Near Washer:
PH: 5.96
Brix: 11
Taste/Aroma: tasted and smelled like DME

Aeration stone:
PH: 5.96
Brix: 11
Taste/Aroma: tasted and smelled like DME

Fermentation Chamber:
PH: 5.96
Brix: 11
Taste/Aroma: tasted and smelled like DME

Stir Plate with Tin foil:
PH: 5.96
Brix: 11
Taste/Aroma: tasted and smelled like DME

Sunday Morning (sept. 6th) I checked each one:
==============================
Control:
PH: 3.64
Brix: 11 (no change)
Taste/Aroma: smelled a little tart, stale bland aroma (very similar to my problem batches), no DME aroma, did not taste.
Notes: PH dropped significantly, but zero brix change.

Near Washer:
PH: 3.64
Brix: 11 (no change)
Taste/Aroma: same as control ^
Notes: PH dropped significantly, but zero brix change.

Aeration stone:
PH: 3.96
Brix: 10 (dropped a whole 1 Brix)
Taste/Aroma: smelled terrible, moldy sour cheesy, sour, tart. Defiantly infected. Did not taste.
Notes: PH dropped significantly, but brix dropped a while 1 brix indicating wild yeast infection.

Fermentation Chamber:
PH: 4.66
Brix: 9.6 (dropped 1.4 Brix)
Taste/Aroma: similar to aeration stone but way more apparent moldy sour cheese, musky. Sour. Did not taste. Def infected.
Notes: PH dropped significantly, but brix dropped a while 1.4 brix indicating wild yeast infection.

24hour Stir Plate with Tin foil:
PH: 3.60
Brix: 11 (no change)
Taste/Aroma: smelled kinda tart, a bit dme aroma, oxizided (which expected). Tasted a couple drops on the tongue. Slightly tart, slight dme taste, not funky, tasted like a finished starter with out yeast character.
Notes: PH dropped significantly, but zero brix change.

Conclusion:
=========
The fermentation chamber and aeration stone jars both had higher finishing PHs 4.66 and 3.96 respectively. They ALSO had a Brix/gravity change 1.4 and 1 Brix respectively indicating wild yeast. They also exhibited complete signs of infection given the ph, aromas and gravity change they are LEAST likely correlate with the issues of my problem batches and here's why.
1.) The aeration stone was not sanitized or sterilized before aerating the jar and I do that before aerating a batch of fresh wort.
2.) my fermenting beers get a airlock and are not exposed to the open air of the fridge for significant amounts of time.

The stir plate, control, and sink/washer jars both had a PH drop down to 3.65~ but the brix/gravity did NOT change at all. This tells me that this is NOT wild yeast but is some type of lactic acid producing bacteria? that is airborne and it is the same strain that contaminated each of the three jars and what has been contaminating my brewery for the last 6 months. Something is living in my air, and being inoculated in the starter and/or during cooling when the wort hits levels the bacteria can survive in.
* as for the control jar, I'm not sure how that contaminated (it shouldn't have been) but it must have sat out longer then I thought before I capped it.

[Eamonn]

Hi, I'm the OP. Funny enough the problem persisted for years for me. I have recently moved house and tried brewing again. I think I’m on the cusp of success, beers taste more beery. A few things that may be contributing to this:

• A tell-tale sign of a low finishing pH for me was an incredibly fast ferment with little to no krausen. pH was dropping very early in fermentation. A healthy krausen and reasonable lag time and ferment time brings me confidence.
• I find that the optimal mash pH for me is about 5.6 – 5.65 measured at room temp. I say “for me” because low mash pH doesn’t always = low beer pH due to buffering mechanisms for different malts / water / yeast / brewing conditions.
• It’s very easy to over acidify. Use a light hand, don’t be pressured (by the forums) into trying to get the mash pH down. I still find it hard to believe you can brew tasty ales with a room temp mash pH of 5.2-5.3. Maybe it will work with lagers because the lager yeast isn’t as aggressive in lowering the pH during fermentation. Or maybe it comes back to buffers keeping the beer pH high enough. I think optimum beer pH is 4.2-4.4 (I’ve degassed and measured some of my favourite commercial examples).
• I’m not using RO or carbon filters anymore, just campden tabs now.
• I’m sure my water supply had something to do with it. I was never ever able to brew good beer with the water supply at my old house (even if I RO filtered it), I had to get water from elsewhere.
• Fermenters get a very good scrub after every batch.
• Dry yeast rehydration is done in a small erlenmeyer flask, with pre-boiled tap water.

[BDawg]

Try boiling your aeration stone (or even better, put it in the pressure cooker).
As said before think in terms of it always 'raining dust' everywhere. Allow NOTHING to sit in the 'dust rain' for any length of time.
Your hoses, chiller, everything should be in the sanitizer essentially right up to the moment you use it.
Keep your wort covered post boil. Don't worry about DMS if you've already given it a good enough boil.
[edit] Try campden instead of AND in addition to a water filter to get rid of any chlorine. [/edit]

Replace the plastic and rubber stuff you have been using. [edit] Try a new water filter element. [/edit]

Keep us posted.

[edited]

[HotCheese]

My wife and I have recently discovered an airborne mold problem in our home and that was probably what was being inoculated in my starters and living on my other equipment as well since I was able to capture it via the open air samples above. We thoroughly cleaned the house, killed any visible mold with a bleach solution, and cleaned out the air filters.

[brewinhard]

Just so you are aware, mold spores are NOT destroyed by star san as well as some wild yeast strains.

[HotCheese]

Just checked a recent batch from the fermentor and the PH came in at a 4.37 which also used the same yeast I've been using since this problem started. I also mashed at 5.4 room temp like I have with the previous batches as well.

I threw away everything plastic including fermentors, lines, thiefs, spoons, ect, that I've had for a few years. I swapped my HLT to my mash tun and got new parts for it, and I also switched to glass carboys. I also switched my sany from star-san to iodophor.

I know I changed many variables but I mentally couldn't bare another failed batch so I just said f-it and switched as much things as I could without breaking the bank.

MAN, It feels really good to finally overcome this issue that has plagued me for far far too long.

[brewinhard]

Good for you. Issues plaguing a good tasting brew can be a serious PITA. Hard to figure out sometimes where they are coming from. Sometimes starting completely from scratch (like you did) can be the best way to start fresh. Speaking of that, I have to ditch my older plastic tubing/autosiphon, etc. and get some new ones for winter brewing.