Stuck fermentation, can it be saved?

[sentfromspain]

So I made two 2.5 gallon batches two weeks ago, testing the yeast to make sure it was alive before adding it to the primary fermentation containers, and went on vacation.

Unfortunately there was a major temperature dip the day I left, and when I came back today I found that the Krausen had not even fully formed. It has been two weeks, can I just carefully bring the containers to a warmer room and add some more yeast? Or are the batches worthless after two weeks not fermenting?

If the batches can be saved, should I aerate it before adding more yeast?

 

[FastAndy]

How do we know this is stuck? What was the recipe, type of yeast, original gravity? What is the gravity at now?

 

[sentfromspain]

Batch one was:
6 pounds pale malt
.6 pounds crystal
.3 roasted
.2 Black
.2 Chocolate
Safale US05
Og original 1.65
OG now 1.55

Batch two was:
4.5 pale ale
.25 crystal
.2 biscuit
.2 chocolate
Yeast was Safbrew T-58
OG was 1.45
OG now is 1.38

 

[FastAndy]

Im not familiar with that specific yeast, i would pitch more yeast and move them to a warmer area. I wouldnt aerate at this point. Who knows, you could be on to something unique here.

 

[Yooper]

That's very strange, as I would expect to see no drop in the SG if it actually got too cold. I've seen S05 ferment down to 60 degrees, so I assume it must have stayed in the low 50s for a while to shut it down completely. The good news is that just picking it up and moving it someplace warmer will get it going again.

Your gravity readings are missing a digit- I assume the current SG is 1.055 in the first beer.

One last thing, though- make sure your hydrometer is correct before worrying too much! Unless you used a refractometer. If you used a refractometer, check with a hydrometer before doing anything!

 

[sentfromspain]

Yeah my hydrometer only puts the last two digits. What can I say, it came with a kit.

What I think happened was that it started to ferment sluggishly, the temp lowered and lowered, forming no krausen, and then stopped because the temp dropped below 50 degrees pretty quickly after (and those yeasts need 60 degrees or above).

I'll just carefully move them over to a warmer room, pitch some more yeast, and cross my fingers for a beer that tastes decent.

 

[Yooper]

Yeah my hydrometer only puts the last two digits. What can I say, it came with a kit.

What I think happened was that it started to ferment sluggishly, the temp lowered and lowered, forming no krausen, and then stopped because the temp dropped below 50 degrees pretty quickly after (and those yeasts need 60 degrees or above).

I'll just carefully move them over to a warmer room, pitch some more yeast, and cross my fingers for a beer that tastes decent.

You don't even need new yeast! The yeast reproduced as evidenced by the SG drop. They just need a chance to warm up back to the mid 60s.