High pH after full attenuation. Caustic or infection?

[jrdnmllr]

I'm stumped.

Here's the backstory.
Made a Rye Saison with 14lb of Pils and 4 lb Rye malt. 7.5 gal @ 1.058 OG

Split it into 2 identical carboys. Before we ran wort through the chiller, we ran caustic (TSP/Oxyclean) and StarSan just to make sure it was clean.Run through plate chiller. One was aerated via shaking, the other via inline pure O2. Shaken wort received 2 tsp Yeast nutrient (urea/DAP). pH of both was 5.2. Perfect.

Because we screwed up a calc (intended only a 5 gal batch) we split one smack pack of Wyeast 3711 between both carboys, but I wasn't super worried because 1) it's 3711 and 2) I like esters, etc in a saison. Airlock them and let 'er rip.

Both had great activity, vigorous krausen, etc. When I took gravity 2 weeks later, one was mostly attenuated (1.010), but had awful smell (nothing I could nail down except fecal) and tasted almost briny. I measured ph and it was over 6! Keep in mind there was nothing growing on it, and it was a little hazy but mostly flocculated.

a) Is this infection? If so, both carboys were cleaned and sanitized the same, right next to each other in fermentation, same temp etc, so what could be the cause? Any specific bacteria that can both eat sugar and raise pH that much?

b) If it was a result of getting caustic in it from the plate chiller, how could the yeast attenuate that fully?

I'm just kinda lost on this one.

(The other ~3 gal is attenuated to the same FG, and it tastes great. Dry hopping this weekend.)

 

[ABVIBUSRM]

i thought infection would lower the ph.

 

[jrdnmllr]

i thought infection would lower the ph.

So did I...

 

[ABVIBUSRM]

I am pretty stumped too..must be some cleaner got in and raised up the ph like you said..but i really dont know..hopefully someone can help out ..im stumped myself

 

[wardens355]

So did one have this "fecal" smell, saltiness, and high pH, while the other was fine?

If both were similar, did you calibrate your pH meter?

 

[jrdnmllr]

So did one have this "fecal" smell, saltiness, and high pH, while the other was fine?

If both were similar, did you calibrate your pH meter?

I used strips ( I know...)
I test the strips on distilled water.
Good one was below 5.
Bad one was "vividly" base.

 

[duboman]

Would you consider descriptors of saltiness and oyster-like for what you are tasting? If so it could be DMS, I know most people associate with cooked corn, vegetal but take a look at this PDF and scroll to DMS/cooked corn, it's a possibility.

http://www.bjcp.org/docs/OffFlavorFlash.pdf

 

[wardens355]

I used strips ( I know...)
I test the strips on distilled water.
Good one was below 5.
Bad one was "vividly" base.

I don't use a plate chiller, but I assume you just run it through the chiller and dump into the fermenter directly, no recirculation? Was the "bad" batch the first to run through the chiller? Was the pH measured before or after running through the chiller?

I wonder if the strips can be thrown off by anything in the beer...
pH Strip Info

 

[jrdnmllr]

Would you consider descriptors of saltiness and oyster-like for what you are tasting? If so it could be DMS, I know most people associate with cooked corn, vegetal but take a look at this PDF and scroll to DMS/cooked corn, it's a possibility.

http://www.bjcp.org/docs/OffFlavorFlash.pdf

I would consider it more if the "good" batch displayed the same profile. I would use sulfidic as a descriptor though.

 

[duboman]

I would consider it more if the "good" batch displayed the same profile. I would use sulfidic as a descriptor though.

Then scroll down to page 22 under sulfuric on that PDF and evaluate.