Can I save this batch?

[CDS]

This is a first for me - I brewed a batch of Kolsch on Monday. It's my go to recipe and I've made it countless times with no problem, but this time, 3 days in there has been absolutely no airlock activity so I took a hydrometer reading, and the OG hasn't budged. Quick rundown of my process and vitals:

• OG: 1.050
• Expected FG: 1.011
• Fermentation temp: 15.5C (60F)
• Fermenting in a conical, with a blow-off tube, inside a temp controlled fridge
• Yeast: WLP029 (pure pitch, no starter). It was a fresh pack, and had started to expand after being out of the fridge, so I figured it was fine.
• Oxygenated
• Current gravity reading: 1.050 (unchanged)

The only deviation from my usual process was that I was out of yeast nutrient and so didn't add any.
Also, I used to use Wyeast and always built a starter, but I got lazy and decided to see what would happen with White Labes Pure Pitch without a starter and it has always provided great results.

Advice would be appreciated. Should I repitch? How long can wort sit around in the sealed fermenter at 60F before it becomes garbage? Thanks!

 

[lumpher]

60 is a little low for WLP029, so no starter might make it more sluggish to start showing signs. I'd warm it up maybe 3-4 degrees and see what happens.

 

[CDS]

Yeah I think you're right. I just blindly switched Wyeast 2565 with WLP029 assuming they'd have the same tolerance. The funny thing is I've made a few batches of Kolsch with WLP029 at the same 60F temp without issue. Anyway, by accident, I left the sample I pulled yesterday out all night in the warm garage, and went in there today to see that it had formed a head and was active, so yeah, it's a temperature thing. Thanks for your reply.