Longer than usual fermentation?

[StevoTosh]

• Today at 6:26 PM
• #1

Hello fellow brewers
I currently have a brew in the fermenter which has taken almost twice as long to reach FG (after lag period) than it should. I'm hoping someone here might know why. Has any one else had a similar experience?
Here is my recipe.

I used 1 packet of Fermentis US-05 sprinkled (not rehydrated) onto 25L of wort at 18.5°C. This was an intentional under pitch, and as expected, there was a long lag period- about 20 hours. I read that US-05 can be sluggish, taking up to 24Hrs to take off- even when pitched at an optimal rate at these lower temps. I have used 05 before, at higher rates, pitched at 21°C, resulting in shorter lag times and always reaching FG in about 2 days after lag. This one took four days! Almost 5 including lag time!
Info from iSpindel via Ubidots. The fermenter has remained sealed.

Calibration is not optimal. FG reads about 3 points lower than actual.

The yeast was well in date (3/2024), kept refrigerated and brought up to 19°C before opening the pack.
The lag time is not the issue for me. It's just that I have never seen such a slow fermentation and I can't seem to find any info on why this has occurred. I will, of course, know how it turned out when it comes time to taste it.

Am I worrying about nothing? Or could there be an issue that I have overlooked? Any ideas?

 

[pvtpublic]

Four days is fine. I ferment almost all of my ales at about 65f/18c and I let them sit for three weeks before I'll consider kegging.

What do you do withe your beer once you hit fg? Do you transfer to secondary immediately, keg/bottle it, or do you let it settle first?

 

[StevoTosh]

Four days is fine. I ferment almost all of my ales at about 65f/18c and I let them sit for three weeks before I'll consider kegging.

What do you do withe your beer once you hit fg? Do you transfer to secondary immediately, keg/bottle it, or do you let it settle first?

I bottle straight from the fermenter after allowing it to settle for up to 2 or 3 weeks depending upon the yeast used. I prime each 375ml (12.7 Oz) bottle in this example (using dextrose monohydrate) according to my priming calculator. (I write my own calculators)

 

[bellhp]

RDWHAHB
Yes you are worrying about nothing in my opinion . It'll be fine if you walk away and let the yeast do it's thing... give them time to go through their life cycle and settle and then you may reap the rewards of the beer they made for you.
Cheers

 

[user 338926]

Maybe I'm missing something, but the graph on the lower right of your image shows that they're basically was no lag, the fermentation was essentially done in 2 days, and the gravity basically flatlined for the remainder of the time.

 

[StevoTosh]

Maybe I'm missing something, but the graph on the lower right of your image shows that they're basically was no lag, the fermentation was essentially done in 2 days, and the gravity basically flatlined for the remainder of the time.

Yes, you're missing something. The graph starts at 1:20pm on May 6th. Fermentation doesn't really kick off until around 11:00am the next day. Flat line doesn't occur until May 12.

 

[BrewnWKopperKat]

@StevoTosh : US-05 can be slow (relative to other strains).

Fermentis has a tips & tricks brochure (link to download page). Page 28 has charts that shows the relative performance of various strains. As the charts show, time to "terminal gravity" will vary some based on wort composition.

 

[jsphlynch]

I currently have a brew in the fermenter which has taken almost twice as long to reach FG (after lag period) than it should.

I used 1 packet of Fermentis US-05 sprinkled (not rehydrated) onto 25L of wort at 18.5°C. This was an intentional under pitch, and as expected, there was a long lag period- about 20 hours. I read that US-05 can be sluggish, taking up to 24Hrs to take off- even when pitched at an optimal rate at these lower temps. I have used 05 before, at higher rates, pitched at 21°C, resulting in shorter lag times and always reaching FG in about 2 days after lag.

You used less yeast at a lower temperature for this batch. To me it seems pretty intuitive that it would take longer to ferment out. Nothing to worry about.

 

[kevin58]

Nothing to worry about here. Yeast are living creatures and often work at their own speed not ours. You changed a variable... pitching rate and saw the results which are that it takes a bit longer - but you still reached the same end result.

 

[user 338926]

Yes, you're missing something. The graph starts at 1:20pm on May 6th. Fermentation doesn't really kick off until around 11:00am the next day. Flat line doesn't occur until May 12.

Ok, opening it and enlarging I see the graduations are 2 days each, not one. Still, surely you expected the lag if you intentionally under pitched, so that can be disregarded. The actual ferment time is probably more ideal imo than your previous batches that were done in no time. In my experience, too fast is always bad. But, to each his own.

FYI, I look at the fermentation being done as of 0 hour 5/11. I'ts .003 from packaging gravity. The rest is just cleaning up, during which time I would have raised the temp to 21c/22c then cold crash. But again, to each his own.

 

[StevoTosh]

Thank you all for your helpful input.
FG is still going down slightly, but I'll keep an eye on it and for now, I'll just sit back, relax and have a home brew.