Wort re-fermenting???

[Rad1]

Hi all,
First time home brewer here, and have a question that I haven’t seen asked or answered in my internet searches.
I have an American wheat ale wort. OG was 1.035. Pitched the yeast, and in about 30 hours it started fermenting and developed Krausen. Temp 72-74% range. Then the krausen went away after about 2-3 days - leaving scattered bubbles on top of the wort. Some solids on bottom. Still had sporadic bubbling at the air lock every 1-1/2 minute or so for a couple of days (none on the 3rd so far as I could tell). Took gravity readings over those 2-1/2 to 3 days and it was stuck at 1.030. Then on the 4th morning (8 days after pitch) checked it and it had thick krausen again and has been fermenting for 3 days now ever since, and still has thick krausen and as of this morning has a gravity of 1.018. Would that mean a wild yeast has been introduced or is it possible that the original yeast restarted? No off odors as much as I can tell. Just haven’t found any examples of others having this happen. Any help would be appreciated.

 

[Beernik]

If you’re not using a temperature control, did you have a temperature swing?

The yeast could have shocked, slowed down, and then picked up again.

 

[Golddiggie]

What yeast did you use?
30 hour lag time??? I see less than 6-8 hours typically(using ale yeast).
Airlocks are notorious for misleading people as to what's going on in the fermenter.
I typically don't do anything until at least 10 days from pitching the yeast (going active as I mentioned).
Depending on the yeast you used, 72-74F is on the high end. Yeast can do very different things to the beer depending on the temperature they ferment at. If that temperature is what the room was at, not the beer inside the fermenter, then you can typically add at least 4-5F on top of that.

At the very least you had a long lag/slow start, stall, then fermentation kicked off again. Give it a week and then see what's going on.
I would also avoid taking frequent samples. Learn patience, or get one of the wireless hydrometers so you don't keep opening up the fermenter (unless you're using a conical type with a sampling valve). Constantly opening up the fermenter is begging for something bad to happen.

 

[hotbeer]

Mine do that quite often. Don't worry about it until you open up a bottle and find out that you don't like it. Then go back to your notes and see if you can find something that might have caused it to taste that way.

Even if the SG readings say it's finished, I'll still wait till it's dead of activity for several days. Took six weeks once. And that is still my favorite batch of all.

 

[Golddiggie]

With good/solid temperature control, you can shorten the time from start to finish (fermenting wise). There are other things you can do to shorten the full time from grain to glass. Not fermenting too warm helps a lot.

My lower strength pale ales (5.5% and lower) typically go grain to glass in about three weeks. Two weeks is the minimum. On the short end, that's 10 days before chilling to carbonate temperatures. Since I carbonate in fermenter, at temperature, with a carbonating stone (does the job in 2-3 days). Otherwise I'd be 4-5 weeks from grain to glass.

 

[Rad1]

Thanks for the quick responses! The carboy is in a room off the garage. It’s dark and does have conditioned air - same temp as the house, though there may have been very slight temp swings being where the room is located. I do use a floating (tilt) hydrometer so I haven’t opened the carboy. I guess I’ll wait it out and give it a taste test when it’s all done. Again, I really appreciate the responses!

 

[Deadalus]

I don't have a tilt but it keeps a record of the gravity and temp? I'm not sure if you are reporting spot checks or full record min max temps.

It doesn't seem like a particularly big change though from what you reported. When yeast activity picks up, it can push the temperature several degrees. If it coincides with overnight, you might not notice it as much depending on ambient temperature in the space. It depends on how your thermostat is set and the how the room is insulate and whether it is conditioned space. Just giving you something to think about not necessarily a cause. My ale space is unconditioned and most of the time I need I have a heating pad to keep it even. This summer I did have a stout that I didn't quite let cool down enough it was like 72F I think and when the yeast kicked in I had to keep hitting it will ice bottles to keep it in the temperature range I wanted for the yeast. My basement gets hot in the summer because I have a dehumidifier in there and it is always cranking out heat until the humidity drops around now.

So it was a wheat ale but do you know what yeast you used exactly? That would help to know.

 

[Rad1]

The yeast that I used was liquid “Wyeast1010 American Wheat”. I should add that I activated the pack and had to let it sit overnight for the wort to cool before I added it

 

[Golddiggie]

Depending on how @Radi1 has the Tilt setup (with something connecting to it 24/7 or not) will determine logging. I'm using a raspberry pi to connect to the two Tilts in my setup. That keeps a log (locally) as well as works to connect up to the cloud for a Google Sheets file per brew. I can connect to the Tilt Pi local page to see what it's doing that second. The cloud logging can only be set to as short as every five minutes. But, that file gives you more info points (OG, SG, attenuation, ABV, etc.) as well as a graph to show what it's been doing. Not too shabby, once you get everything working. Also, remember to NOT name the batch in the software until it's in the beer. I made that mistake once and it read the SG of Starsan as part of it's data point, which threw the cloud logging off.

 

[Deadalus]

The yeast that I used was liquid “Wyeast1010 American Wheat”. I should add that I activated the pack and had to let it sit overnight for the wort to cool before I added it

Ah, I just recently ordered that one and it is in my fridge but I only brew wheats occasionally and previously was using the White Labs wheat yeast. The Wyeast one has a temperature range of 58-74F. I will sometimes do searches on the yeast + temperature range to see if there are any reports about how the yeast behaves at different temperatures to get an idea of what temperature I might use for temperature control. Sometimes you'll get some hits on different behaviors. You might have already done that but maybe a regular user of that yeast will have something to note.