Will a batch in "secondary" complete fermentation?

I created two 1-gallon small-batch experiments on Wednesday June 12. Today, June 16, I transferred each of those beers to secondary to harvest their yeast for a big barleywine I brewed (today).

Active fermentation in the barleywine has already started–the blow-off tube is already bubbling–and it’s only been 3 hours since pitching. I assume this means the harvested yeast was still active. This leads me to two questions:

(1) If the assumption that the harvested yeast is still active is true, I assume this also means that fermentation wasn’t complete in the small batches?
(2) If #1 is true, will the “leftover” yeast in the secondary be sufficient to finish out the batches, or should I sprinkle a bit of US-05 in there?

I should state that the krausen on both small batches had dropped, though I didn’t check the gravities… I’m not all that confident in the small batch OG readings I took, anyhow, to put much faith in a FG reading.

Your thoughts?

You allowed 4 days for primary? Seems a little short depending on temps. But you probably had lots of very hungry yeast and I am sure there was plenty of yeast that transferred.

[quote=“Silentknyght”]I created two 1-gallon small-batch experiments on Wednesday June 12. Today, June 16, I transferred each of those beers to secondary to harvest their yeast for a big barleywine I brewed (today).

Active fermentation in the barleywine has already started–the blow-off tube is already bubbling–and it’s only been 3 hours since pitching. I assume this means the harvested yeast was still active. This leads me to two questions:

(1) If the assumption that the harvested yeast is still active is true, I assume this also means that fermentation wasn’t complete in the small batches?
(2) If #1 is true, will the “leftover” yeast in the secondary be sufficient to finish out the batches, or should I sprinkle a bit of US-05 in there?

I should state that the krausen on both small batches had dropped, though I didn’t check the gravities… I’m not all that confident in the small batch OG readings I took, anyhow, to put much faith in a FG reading.

Your thoughts?[/quote]

YEast are going to stay active and will kick back in if feed more sugars if they are done eating, factors come into play on how long that reactivation will take
You harvested only after a few days so yeast was probably going still or just finishing.
Yeast are not just going to die or go dormant that quickly, you could have let them go a month and used that yeast from the gallon carboys

As for the yeast that is left in suspension to finish? Who knows…what was the pitching rate? how much yeast was in suspension? etc,… etc…

Relax. Don’t worry. You’re fine. Have a homebrew.

With a measly gallon you almost certainly over-pitched to begin with so the short ferm time is to be expected. Not to say it might have been better to pick up a little of the slurry when you transferred, you’re probably fine though.

how would you know he over pitched?
A gallon pretty much takes just as long as 5, as 10 as 1,000

Maybe but if you over-pitch then it will go very quickly. He stated that his 1gal batches finished in under four days. And if you’re growing something primarily to harvest yeast, of course you’d overpitch. Why would you go to the trouble of measuring out 1/5th of a packet of yeast, or a partial smack pack or vial?

So Silent, how much yeast did you pitch in each gallon?

Maybe but if you over-pitch then it will go very quickly. He stated that his 1gal batches finished in under four days. And if you’re growing something primarily to harvest yeast, of course you’d overpitch. Why would you go to the trouble of measuring out 1/5th of a packet of yeast, or a partial smack pack or vial?

So Silent, how much yeast did you pitch in each gallon?[/quote]

Yeah, I wasn’t really precise. I worked up a pint of slurry into a 1200ml starter, and attempted to give each batch about 600ml. I bet dollars to donuts that I overpitched.

Yeah, not my best moment, but eh, I’m okay with a little deviation from best practices for an experiment and in order to perhaps learn a bit more. If I did it perfectly all the time, what would be the point? :smiley:

As long as you pick up a little slurry when you transfer to secondary, I don’t think you’ll see anything stall out. its when you try and get it off super-clean, that there can be issues. Seems to me that some of the better-floccing yeasts will drop quick and continue secondary metabolism (eating acetaldehyde and such) at the bottom of the fermentor.

good beer? :cheers: