Cold Snap Stopped Fermentation - How To Restart?

[FMWarner]

Hi, guys! Everyone here is so helpful, I'm hopeful that someone can advise me on this issue.

I'm brewing a Mangrove Jack's Chocolate Brown Ale beer pack. I tried fermenting outside for the first time because the weather was warm (mistake, noted.) For the first few days the fermentation was going well, foamy and lots of bubble action in the airlock. Unfortunately, we got an unexpected cold snap and overnight the outside temperature plunged. In the morning I checked, and the thermometer on the fermenter wasn't even high enough to register (it starts at 18C.) I brought the fermenter inside and put it on a heating pad...by that night the brew was up to 26C. However, fermentation has not restarted. Here's a timeline of SG:

Day 1: 1.038 SG (brew day, before pitching yeast)
Day 4: 1.019 SG (the day I brought the brew inside after the cold)
Day 14: 1.016 SG (today)

So, it seems that fermentation has essentially stopped. I've seen other people with similar problems warned that re-pitching more yeast almost never works and that it's best to wait it out. But after 10 days, I'm thinking that's not going to work. According to the recipe, this ale should come in at about 1.008 SG. Should I just take the lesson learned and bottle this 2% ABV ale (it tastes okay), should I try more yeast, or should I wait longer?

Thanks for any help!

 

[Aonghus]

Hi, guys! Everyone here is so helpful, I'm hopeful that someone can advise me on this issue.

I'm brewing a Mangrove Jack's Chocolate Brown Ale beer pack. I tried fermenting outside for the first time because the weather was warm (mistake, noted.) For the first few days the fermentation was going well, foamy and lots of bubble action in the airlock. Unfortunately, we got an unexpected cold snap and overnight the outside temperature plunged. In the morning I checked, and the thermometer on the fermenter wasn't even high enough to register (it starts at 18C.) I brought the fermenter inside and put it on a heating pad...by that night the brew was up to 26C. However, fermentation has not restarted. Here's a timeline of SG:

Day 1: 1.038 SG (brew day, before pitching yeast)
Day 4: 1.019 SG (the day I brought the brew inside after the cold)
Day 14: 1.016 SG (today)

So, it seems that fermentation has essentially stopped. I've seen other people with similar problems warned that re-pitching more yeast almost never works and that it's best to wait it out. But after 10 days, I'm thinking that's not going to work. According to the recipe, this ale should come in at about 1.008 SG. Should I just take the lesson learned and bottle this 2% ABV ale (it tastes okay), should I try more yeast, or should I wait longer?

Thanks for any help!

I calculate your brew is at 2.8% ABV, if you want it to go higher try the following:
Boil up some DME in chlorine free water, cool it and add it in the fermenter to restart the yeast. See if that does it for you. That Mangrove Jack is supposed to be the dry version of PacMan yeast and Pac Man has always attenuated very well for me, did you use all grain DME or Liquid Extract? Some of those leave a higher final gravity.

 

[jtratcliff]

Are you fermenting in a bucket or a carboy?

If in a bucket, sanitize a long spoon and gently stir to get some yeast back in suspension. There should be plenty of healthy yeast and plenty of sugars left. You just need to wake those bad boys up.

 

[FMWarner]

I calculate your brew is at 2.8% ABV, if you want it to go higher try the following:
Boil up some DME in chlorine free water, cool it and add it in the fermenter to restart the yeast. See if that does it for you. That Mangrove Jack is supposed to be the dry version of PacMan yeast and Pac Man has always attenuated very well for me, did you use all grain DME or Liquid Extract? Some of those leave a higher final gravity.

Thanks, I'll try that. Like I said, it tastes fine, but I'd like a little more kick. I used all grain DME.

Could you tell me which fermenter you used? I suggest you can buy one dual stage temperature controller which can control the temperature well. ITC-1000 temperature controller is good and cheap (16.49USD, if using the claim code 3EPD7NRR, 10% off). You can try one.

Thanks for the tip! I used a 30L fermenter that looks just like this one:

Are you fermenting in a bucket or a carboy?

If in a bucket, sanitize a long spoon and gently stir to get some yeast back in suspension. There should be plenty of healthy yeast and plenty of sugars left. You just need to wake those bad boys up.

Thanks for the tip...I did give it a stir when I first brought it inside, and then again a few days later when the SG didn't appear to be moving. I thought, like you, that it might do the trick.

 

[ArcaneXor]

"Rousing the yeast" works maybe one time out of 100. There are a few things you can try, but these days I move straight to pitching a vial of WLP099. Unless the problem is enzymatic (i.e. incomplete conversion), WLP099 works nearly 100% of the time.

 

[jahdub]

If you're doing partial boils with extract based recipes, there's a very good chance you wont get down to 1.008FG. I've only personally gotten so low with all-grain. Most of my extract brews have finished 1.015+