[Gail Kahle]

First time trying out this newer yeast. Cooked a low gravity wort (1.038) and placed the immersion chiller in the wort while sanitizing the fermenter.  Not realizing that my ground water temperature was currently extremely low, when I check wort temperature it was down to 63 F. 

Pitched the rehydrated Philly Sour at 63 F.  It took a fully 48 hours to start, and now - 72 hours out -  the yeast activity seems unusually  leisurely. Temp in the fermter has hovered around  65 F.

Any experiences with low temp fermentation on this yeast?  Any suggestions or predictions to expect?  Should I though in an envelope of US-05 after a couple days?

[Megary]

I found this on Lallemand's web site regarding Philly Sour:

• Lactic acid is being created from glucose
within the first 24-72 hours of fermentation
 › Apparent wort density does not significantly drop during the lactic production phase.
 › Very little CO2 production occurs during this stage
 › Ethanol production will typically begin 24 hours after pitching.
• Wildbrew Philly Sour™ benefits from high fermentation temperatures (22 - 30C)
› A higher fermentation temperature is recommended if a lower pitch rate is used.
 › Similarly, if fermenting at a low temperature, a higher pitch rate (100-150g/hl) is recommended
• Ethanol production picks up once the yeast starts to metabolize maltose
› Typical attenuation levels are: 70-85%, with a pH range of 3.2-3.5, and Titratable acidity (lactic acid) of 3-8g/l.

https://www.lallemandbrewing.com/wp-content/uploads/2021/10/LAL-bestpractices-Philly_Sour-ENG-A4.pdf

I've never used this yeast, but it looks like you pitched underneath the yeast's comfort zone.  Maybe warm it up a bit and let it go??

[Drewch]

I've used PhillySour a handful of times now, and in my experience, it is just slow.  I wouldn't worry yet.

Maybe I've been running it too cool, too, but I'd give it at least a month or so in primary.

[majorvices]

it's really slow fermenter but it gets the job done. It only creates lactic like the first 72 hours or so after that you can speed it up with regular ale yeast if you like. I fermented mine at 68 then tried to ramp it into low 70s. Took 3 weeks. maybe more, I wasn't;t in a hurry and added pineapple puree so it may have taken 4 or even more.

[Drewch]

I did a month in primary and then aged on plums for 3 months with some Brett --- came out nice.

Some writers say a healthy percentage of simple sugar adjunct helps with the lacto production.  I haven't done enough comparisons to verify -- I've done a ~10% sugar addition to all but my first batch and have been happy with the final acidity.

[kramerog]

My experience matches what others here have said and elsewhere. Lallemand said something to the effect of if a normal fermentation takes 2 weeks, expect it to take 3 weeks with Philly Sour. The Philly Sour yeast was found on fruit; it isn't optimized for wort fermentation. FYI, I had no problem bottle carbonating with this yeast the one time I tried.

[JRobert.]

If you go to Youtube Lallemand has at least two informational vids on Philly.