Too cold? Possible infection?

[branCHEs]

I have two beers fermenting right now.

Black IPA
Safael US-05 yeast - temp range 59-75 degrees Fahrenheit
Brew day - 3/2/13

Scotch Ale
Wyesst 1720 Scottish Ale - temp range 55-75 degrees Fahrenheit
Brew day - 3/9/13

They are both in my room and the only way I can control temp is by letting the cold Minnesota winds through my window. On Monday morning (3/11/13) I knew I would not be able to come home until this morning (3/13/13) because of work. I lefty bedroom window cracked open. When I got home, both beers were at 56 degrees Fahrenheit.

To make things worse, the water in my bowl that the Black IPA's blow off tube was in had evaporated to the point that the blow off tube was not submerged. I just filled it back up.

Enough time hasn't gone by to tell if there is any action in the Black IPA.

What are the chances that I ended fermentation early by making the yeast go doormat? How can I restart fermentation if that is the case? Just give it a good swirl once it is back with in the yeasts temp range?

Lastly, what are the chances that any micro organisms got through the blow off tube and into my beer since the water had evaporated in the blow off tubes bowl?

 

[DisturbdChemist]

That is a wide range for the beer. Does the beer temperature swing that much? For the infection you have to discribe if it taste off or show pics if something is forming on top of the beer.

 

[DisturbdChemist]

I'll just warm up the beer and shake it to get the yeast in suspension again and it should be fine. If it was warmer then it'll throw some off flavors but the beer should be fine because the yeast should still be eating but it'll just be at a slower pace. Wrap it in a blanket and move to a warmest (65ish) place in your house.

For the air lock it should be fine. There might be some suck back because of the temperature change but it should not infect the beer. Bacteria does not have legs and will not crawl up the blow off tube. Relax and have a beer. Just keep your eye on the temperature and keep the blow off submerge.