Zero fermentation after 48+ hrs

[nickmv]

So I brewed up a Fat Tire extract clone, and used Wyeast 1272 American Ale II yeast. I smacked the pack, let it sit for 3+ hours. It seemed to bloat somewhat, indicating live yeast. I've brewed 5+ batches now with no issues, and pitched this one at 80F like always (both yeast and wort temp) and I've seen nothing over 48+ hrs later.

To be sure, I took a gravity reading, and it hasn't budged 1 point, and currently sits dormant at 1.050. I'm thinking the yeast was dead, but since I already threw away the smack pack, fat chance of confirming by any date checking. What could have gone wrong here? After pitching, I used a swamp cooler to get it to around 68. I accidently ended up getting it to 63 in the wort, so I thought maybe it's just slow and sluggish, but that surely wasn't a change that should have shocked the yeast dead for good, not to mention 63 is still within the yeast's active temp range; it takes 8-12 hrs for a swamp cooler to change the wort temp. I also aerated the wort 3 times since I racked it to the primary (something I usually never have to do after racking).

I've got a Wyeast London Ale yeast pack I'm currently saving for an Oatmeal Stout, but I'm thinking that I need to go ahead and get it out and get it prepped to pitch in this Fat Tire since nothing's happened.

Any suggestions?

 

[android]

i'd give it another day and then consider the 1028. it could be that you had a really low cell count in that smack pack and they're just getting multiplied, ready to roll.

 

[GuldTuborg]

Wait another day and see how it goes. Some yeasts settle out fairly permanently at dramatic temperature drops, so if you plan on chilling to the mid 60s, do it before pitching yeast, not after. It's possible that's what happened, but more than likely your yeast is just taking some time in the reproductive stage.

If after another 24 hours or so you don't have any change in gravity, I'd pitch a packet of US-05, which is close to what you used. You do have extra packets of dry yeast sitting around for emergencies, don't you?

 

[nickmv]

Def don't have emergency packets. It wouldn't be a real experience If I had remembered those, now would it?

I've got a bottled Summit IPA that used Wyeast 1056 American Ale I yeast, and I'm gonna make a starter from a bottle or two of yeast harvested from them. I'm not too comfortable with pitching the London Yeast in a Fat Tire clone. Assuming I don't open the lid again and I get this started made in the next 2 days, I guess I shouldn't worry too much. Other than risking infection, is it bad to leave wort sitting there?