How long do I have to bring down temperature?
 

I brewed a pale ale last night and this morning I check the fermentor and it was reading 70F. I'm at work and can't cool it until at least 7pm tonight. Will the beer be ruined with eaters by that point? The yeast I'm using is Wyeast London ESB.


Thanks,
Zach

You will probably get some esters and other minor off flavors, but it is far from ruined. All of these minor off flavors can be conditioned out, given a bit of extra time. After you bottle, plan for about 6-8 weeks at about 70F to bottle condition and carb, and those off flavors will mellow and meld and you'll hardly notice them.

Start another brew in the meantime!

I was able to have a friend cool the fermentor after about 12 hours since I pitched the yeast. Is this going to help?

What temp is it at now?

65f

Off flavors from high ferm temps are pretty much only a worry during the most active part of fermentation. By cooling it down after 12 hours, you probably reduced your off flavors by a good 75%, but you may still have just a tinge from the 12 hours, depending on when the active fermentation took off.

Just brew as normal, throw one in the fridge when it's time, and if you detect any off flavors, give the batch a few more weeks to bottle condition.

How accurate will the stick on thermometer be if it's slightly underwater from the bath the bucket is in?

FWIW, I will hold off on pitching until I get the target temperature...not sure, but I figure pitching late is better than pitching warm.

It's not the best practice to lower your fermentation temps in the middle of fermentation. Best practice is to pitch cool and slowly raise the temp over the course of fermentation

Will the water in the tub be similar in temperature to the wort in the fermenter?