A Tale of Two Carboys

[drlafone]

Hi All,

I'm a new member of the forum but a long time HB'er who finally broke down and went all-grain. While there's certainly more work involved, I'm hoping the product will make it worth while.... and I'm getting 10 gallons instead of 5 per batch. Which brings me to my question: I brewed a Czech Pilsner on Sunday and with 10 gallons I had to split the batch into two glass fermenters. Because I'm lazy, and didn't make a starter, I directly pitched a vial of German Lager WLP800 into each carboy at about 75degrees. So we're talking the same wort, same temperature and same yeast. One fermenter is krausening and bubbling, and the other ain't movin'.

I know this board is full of questions about slow starting fermentations, but this situation seems odd to me. Any ideas?

 

[MalFet]

Most likely explanation is that your two vials had different levels of viability. There are plenty of reasons why that could happen, but we won't be able to speculate without knowing more. The less healthy one is taking longer to build up to an appropriate population.

But the bigger question here is, Why the heck are you fermenting wlp800 at 75ºF?!?

 

[bottlebomber]

You know, I used to THINK I was a homebrewer till I found this site, and the discovered how little I really knew about the process. Just stick around awhile, and you'll pick up all kinds off cool tricks

 

[drlafone]

Yea, I don't think I stated that very well.... I cooled the wort to 75 degrees, pitched the yeast at that temp, and then put in the temp-controlled fridge at 52 degrees.

In retrospect, I probably should have let the wort cool down closer to fermentation temp before pitching, and used that extra time to at least get a starter going....

 

[MalFet]

Yea, I don't think I stated that very well.... I cooled the wort to 75 degrees, pitched the yeast at that temp, and then put in the temp-controlled fridge at 52 degrees.

In retrospect, I probably should have let the wort cool down closer to fermentation temp before pitching, and used that extra time to at least get a starter going....

One more possibility then is that your yeast flocked out during the temperature drop. Quick cools shortly after pitching can cause yeast to go dormant. In my experience, they usually wake back up but on a few occasions I've seen it not happen. Hard to say for sure, though. Time will tell you all you need to know.

 

[bottlebomber]

Of course you also know that for a lager you underpitched by about 2/3s right? A vial has about 100 billion yeast cells and you probably need 300 billion for a standard lager. I would seriously consider obtaining more yeast to improve the quality of the batch

 

[drlafone]

I think you're right about me under pitching.... now you and John Palmer have both told me. I think I'll pick up a new set of vials. Thanks for the input guys.

 

[drlafone]

OK, fast forward 3 weeks... After a slow start, my underpitched yeast did wake up and I ended up with a pretty aggressive fermentation in both fermenters. I had intended to get a pair of vials and add to the pitch, but before I could acquire them, it took off.

So today I was getting everything ready to move from primary to secondary, but the air lock is still bubbling about 4 times per minute and the krausen hasn't fallen.

I'm assuming the best thing to do is just let it go in the primary another week. But what would be the advantages or disadvantages of moving it now?

 

[passedpawn]

FYI if you are using a chest freezer for temp control, make sure neither of your carboys touch the walls. If a carboy is touching the walls it will be colder and ferment more slowly. The walls can get very cold and inhibit fermentation altogether.

 

[drlafone]

FYI if you are using a chest freezer for temp control, make sure neither of your carboys touch the walls. If a carboy is touching the walls it will be colder and ferment more slowly. The walls can get very cold and inhibit fermentation altogether.

I'm using a regular fridge with a temperature controller. It's been sitting at 53 degrees pretty steadily for the past 3 weeks. I'm guessing it's still going because of the slow start. Good thought though.

 

[COLObrewer]

OK, fast forward 3 weeks... After a slow start, my underpitched yeast did wake up and I ended up with a pretty aggressive fermentation in both fermenters. I had intended to get a pair of vials and add to the pitch, but before I could acquire them, it took off.

So today I was getting everything ready to move from primary to secondary, but the air lock is still bubbling about 4 times per minute and the krausen hasn't fallen.

I'm assuming the best thing to do is just let it go in the primary another week. But what would be the advantages or disadvantages of moving it now?

Well depending on the current gravity you may want to perform a diacetyl rest prior to lagering or transferring but your first step is taking a gravity reading and also tasting the sample to see if it tastes like butterscotch.