Cherry Belgian ale: cherries floating ok?

Totally fine! That's what they do.

 

My only comment/discussion topic is that by looking at that photograph there seems to be a lot of head space (i.e., air) in that carboy. I am assuming that the beer has completed primary fermentation and this is a secondary. Is this 'excess' amount of air an oxidation concern?

Jim (@NeroFiddled) it would seem that you have experience here, do you think this is too much headspace? Maybe there is sufficient sugars in the sour cherries that a pseudo-secondary fermentation occurs and the CO2 outgassing will 'scrub out' the air (oxygen)?

Cheers!

 

Absolutely.

There will be fermentation going on, and not just because of possible external yeasts. (Freezing does not kill bacteria/yeast).

I wouldn't worry about it though, that's how everyone made beer years ago! If something gets funky just hope for the best.

As to the headspace it's a bit much but it should be fine as well. The racking could have picked up some oxygen though, hard to tell, but I doubt there was any pre-gassing with CO2 going on.

It'll be a toss of the dice, let's hope it comes out nice.

 

If it were me, I would sanitize the cherries, and then I would crush them a bit once in the fermenter, and I would rack right on top of them from primary so as to keep the fermentation going a bit.

I'll also note, although it doesn't really fit your situation as you're getting free cherries, but I greatly prefer just using juice or puree from Oregon Fruits.

 

You could dunk them in star san, raise them to pasteurization temps in a sauce pan and freeze them afterwards in a sanitized tupperware, or soak them in vodka.
That is a lot of head space, but I have seen people not account for the volume change from the fruit additions as well. And yeah, the sugars in the fruit should be fermenting out now. Two months may be a bit long, but give it a taste at a month and see.

 

And you could continue this practice for future batches but I wouldn't. That is 2 gallons of air (20% oxygen) in that headspace which yields too much oxygen (which leads to oxidation).

Cheers!

 

I have used frozen fruit in secondary with no sanitation step on the fruit and didn't seem to develop infection. If the beer is pretty much fermented, the only sugars are the fruit sugars, there should be a higher population of yeast, better adapted to the lower pH and higher alcohol environment than the bugs on the cold fruit. I think the most likely scenario is the yeast dominate the fermentation of the fruit. The worst case scenario is Jurassic Park.

 

for the headspace concern, wouldn't the fruit re-ferment an create more CO2? I hope so because I have a 6 gallon cherry berliner going in an 8 gallon bucket (my cherries are floating as well btw)

 

I discussed this above in this thread with @NeroFiddled.

It is possible (likely?) that the pseudo-second fermentation will yield sufficient production of CO2 to 'scrub out' the air (oxygen) of the large headspace. But I would suggest that the larger issue is why take this chance? From my perspective it would be better to use a secondary vessel that is consistent with the batch size; use a 3 gallon secondary for a 3 gallon batch. Once beer has completed fermentation (or neared completion) it is a best practice to minimize exposure of the 'finished' beer to oxygen to prevent/mitigate oxidation.

Cheers!

 

You should be fine with 6 in an 8 gallon. Always best to limit air space but unless you have a lot of carboys of various size you're probably going to have to make do at times. I tend to split my 6 gallon batches into a 5 gallon and a 1 gallon carboy so I can experiment with additions to the 1 gallon.

 

A three gallon batch in a three gallon fermenter would likely blow-off due to fermentation of the sugars in the cherries. When I secondary on fruit, I make sure there is some headspace. Not necessarily as much as I would for a primary fermentation, but something.

As already mentioned, freezing doesn't kill everything. But I would say the risk of noticeable infection from what's left is small, since you rinsed and then froze. Almost all of my fruit beers have been done with clean, frozen then thawed fruit. No issues so far. And I can't recall anyone reporting any issues when they have done the same.

That said, if you wanted to dunk the fruit in Starsan, it wouldn't hurt anything, and might help if there were otherwise going to be a problem. But Starsan isn't really designed to sanitize organic material.

If you wanted to take the risk from, I dunno, say less than 0.1% to virtually 0% (just making up numbers), you'd probably need to pasteurize the fruit. But if you pasteurize, be careful not to overdo it and risk pectin gel formation, which would add haze to your beer.

 

I agree. There are winestains on my cellar floor from my Sour Grapes sour ale.

 

adding to this, I just kegged my cherry berliner. Its awesome. However, after the 4 weeks on cherries, the tops developed mold (where the cherries were not in contact with the beer).
from what I've read, I determined it would be ok if I siphoned from below this mold issue and leave ~1 gallon in the ferm bucket.
having said that, I would rather not have moldy cherries in the first place. Next time I will do a better job of CO2 purging and decreasing headspace I guess. any other suggestions would be great. thanks!


P.S. the beer tastes terrific and very clean so I hope that means I'm in the clear!

 

I put my fruit in Muslin bags and weigh them down with random Stainless steel parts from the hardware store. It keeps the fruit submerged and mold free.