Split Batch Fermenting Very Differently

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

LoudounBrew

Well-Known Member
Joined
Jan 18, 2012
Messages
49
Reaction score
1
Location
Purcellville
Made a 10-gallon batch of Two-Hearted Ale clone a few weeks back. Split the batch between two carboys. One got very clear wort, the second got a ton of trub (I more or less just dumped it all into the carboy). Due to an accident, I likely underpitched, probably used 1-and-1/2 rehydrated bags of Safale 05 between the two carboys.

Both carboys fired up within 12 hours, especially the carboy with the clear wort which had a very good sized krauzen. After about a week, the carboy with the trub dropped the krauzen and cleared out. But the other carboy continued to bubble like mad.

After a day or two of this gap, I took a reading. Sure enough, the trub carboy was 1.010, while the clear wort carboy was 1.022. After two weeks of fermentation, I took another reading from the clear wort carboy and its gravity had dropped to 1.012, so fermentation was still going and it tasted pretty decent. But it was still bubbling and not clearing.

Now, 2-and-1/2 weeks into fermentation, the trub carboy has cleared very nicely, while the other carboy is still bubbling about every 10-11 seconds and remaining cloudy, though a bit clearer than three or four days ago.

The carboys were fermenting for the first two weeks at ~62, which is on the cool side and would explain a somewhat slow fermentation pace, and then raised to 68 over a couple of days. The cool initial temp would explain a slow pace but not the difference between the two carboys.

Not sure that I'm necessarily looking for answers (the yeast gods work in mysterious ways), but it's amazing to me that two carboys under the same conditions (except the trub, which certainly may be the cause) could behave so differently.

Lesson for me: You can only control yeast so much.
 
I'm a big believer in the "dump it all in there" method, as well as the "don't touch it for at least a month" / "secondary is for suckers" philosophy. I honestly think that a good dose of trub does an awesome job of (a) feeding the yeast at the beginning of fermentation and (b) clearing the beer at the end of fermentation.
 
I agree. I'm no expert on yeast, but I have to imagine that the trub in the second carboy feed the admittedly underpitched yeast and help them along, while the clear wort carboy yeast have been struggling. Luckily, the clear wort beer seems to taste pretty good, so I don't think anything is ruined.

I'll be curious to take each and see if there's a difference in the final product.
 
Back
Top