Made my first major mistake after 2 years of brewing....

So I brewed an IPA last night, ended up killing a 6 pack of my APA in the 4 hours it took to brew....

Long story short I pitched the yeast at 70F, put my fermenters in my fermenting fridge, set my Johnson temp controller to 62F and went to sleep.

When I woke up I was surprised to find the fridge running and my beer temp down to 60F! Looked at my Johnson controller and it read 68F! DOH!

I knew right away. I forgot to reinstall my temp sensor probe back into the fridge! The freaking thing had run all night...it was 45F in the fridge!

The beer temp never got below 60 but the yeast is doing absolutely nothing. Is it asleep? I am going to warm it back up to 65F slowly and hope for the best.

The yeast is fine. We store the yeast in a fridge that is much colder than that in both liquid and dry form.

Depending on the yeast strain, warming the beer up may not even be necessary. The best results I've gotten from US-05/WLP001/Chico have been fermented in the very low 60s (ambient temp of 58). I seriously doubt that you've harmed your beer in any way.

It'll be fine. I did a lager a few months ago and dropped the temp down to about 35 for almost a week before I caught it. Raised the temp, let it ferment out, and drank it.

I've left the sensor out twice in my keezer and frozen everything solid. That's a fun one there.

Wow, thanks I feel much better now. I don't want to run into a problem as this is my most expensive IPA yet (Amarillo/Simcoe/Citra).

The yeast is US-05 by the way. It was washed yeast pitched to a starter, fermented out, decanted and pitched at room temp.

What happened is even though the temps are still in a practical range for the yeast,a large temp drop can shock them into dormancy. Warm it up slightly & give it a lil swirl. I've done that before to get them going again. But it took untill the next day to see some little action on their part.
So it's in a temp range that won't harm the yeast,they just shock from rapid temp fluctuations.

You're fine. Maybe even better off than before. Ive done way worse. Try scorching your beer while direct firing the mash tun doh.

I agree that everything is fine. At worst you just stalled everything for 12 hours. Install the probe and proceed. I doubt it even got cold enough to stop the yeast from fermenting - just making them work slower.

I will update if and when they wake up!

Thanks!

They will. Yeasties are some tough lil critters. They're very resiliant,as they've proven to me time & again.

Update:

Thanks for the advice! I was at high krausen just 24 hours after pitching...a bit longer than usually for my starter pitched beers but I'll take it! US-05 never fails me!

Agreed with all the other posts. The only time this might be a problem would be at the end of fermentation in a big beer that wasn't quite finished out yet. Then the yeasts could fall asleep and not really ramp back up. But you're talking about the aerobic phase and the yeasts are ramping up and multiplying getting ready to eat some sugar. Sure there's a slight chill in the air, but they're not going to let that ruin their feast!

Edit: I see in the post above that your dilemma is squared away. I am a chronic low fermentor of ales fwiw. The yeasts take longer to finish the job at low temps, but ferment very very clean.