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US04 Stalled due to cold? Will it restart? Or is it done?

So, this is the first time I’ve used US-04… I pitched on Monday, noonish, and left it in the garage. Fermentation was quite active by Tuesday morning. Then, the weather changed, and the temperature dropped a bit, with the beer temperature falling from about 66F to about 60-61F, but it seemed okay. When I checked on it Wednesday evening, the krausen had dropped and the visible signs of fermentation were gone.

I’ve since then brought it inside and used a carboy wrap to heat it up to 68-70F, swirled it gently a bit, and held it at 66-68 overnight.

Again, this is the first time I’ve used US-04. Is this rapid’ish fermentation behavior normal? Or did I cause it to stall due to the cold? If stalled, is it likely to resume fermentation, or should I expect to need to pitch fresh yeast?

Thanks & cheers.

That temperature is still well within that yeasts range. I can’t image low 60’s put it to sleep. I routinely ferment ales in the low 60’s if not upper 50’s with no issues.

You need to take a gravity reading to be sure, but I would assume it simply fermented out.

The first beer I made was with us 04 and I had the same issues. Started fast around 75. Put it in the basement and overnight it cooled down to about 50. I brought it back upstairs and gave it some twisting action because I wanted to get the yeast back in suspension . Kept it in the mid 60s . As soon as it warmed up it started bubbling again. The beer turned out well. I think tht yeast is pretty forgiving. I had the temps all over the place and it kept chugging along

[quote=“dobe12”]That temperature is still well within that yeasts range. I can’t image low 60’s put it to sleep. I routinely ferment ales in the low 60’s if not upper 50’s with no issues.

You need to take a gravity reading to be sure, but I would assume it simply fermented out.[/quote]

Yeah, a gravity reading is needed, but I’m at work. I’ll take one when I get home, unless the visible signs of fermentation have resumed.

S-04 is also a quick fermentor, sure there are exceptions but for the most part it seems true of most English strains. A couple days does seems pretty quick though.

Keep on swirling. Swirl swirl swirl. But it’s probably done anyway.

Refractometer readings:
OG: 15.9% Brix
Now: 10.2% Brix

That means the “FG” is in the 1.22 - 1.27 range, depending on the calculator you use. I did add 1lb of lactose to the boil—it’s a “milk chocolate stout”—but still, that doesn’t agree with the reading I took from the first time I brewed this recipe, where I reached about 7.4%.

What to do now?

04 is pretty strong even down in low 60’s and can look to be done, but I always go 2 wks-17 days before I even do my hydro thing. I do this so it cleans itself up…just me.

I was not optimistic… I re-hydrated and added a second packet of US-04. I feel better now. :lol:

Let us know if the 2nd 04 you pitched brings it down any, and how it turns out. thanks.

Today, May 4, I checked the gravity. It’s been a week since I added the extra US-04. The refractometer reading is now 9.8 to 10.0%. So, it doesn’t look like much additional effort for an entirely fresh packet of yeast.

I had some 04 stop at 1.022 in a apa and I expected 1.015, I must say that the taste of the 1.022 was not to my liking but it was drinkable seeing that it is gone. I mashed it at 154 but do remember that when I added strike water I overshot and the mash was at 158 for maybe 2 minutes before adding cool water to bring the temp down, could this be what caused the high fg? or is 2 minutes at that temp no big deal in a mash?
I’m drinking a porter as I type that was fg 1.020 and its perfect to me. are you going to bottle yours at that high of a fg? I ask because I really have no idea where the cutoff is on taste and high fg with porters and stouts ?

So, I checked the gravity, today, a week after the extra yeast was added. The refractometer reading is perhaps a bit lower, at 9.8% to 10.0% (i.e., compared to 10.2% a week earlier).

It’s a sweet stout, with a pound of lactose added to the boil. If lactose has a 30 PPG rating, then for my 5-gal batch, the lactose is raising the FG a whole +0.006 points. So, if my converted FG is ~1.022, then it really should be closer to 1.016… still seems high.

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