Adding cherries, how big of carboy?

I've got a 6 month old turbid-mashed Lambic-style beer (https://www.homebrewtalk.com/f72/lambic-style-kriek-102829) that I'm going to add 10-15lb of fresh Door County tart cherries to. It's a 5 gallon batch in a 5 gallon carboy now.

1. How big of a carboy will I need to fit the cherries & beer volume into?

2. How long do I need to keep the beer in contact with the cherries? (i.e. how long do I need to keep the beer in this larger carboy vs. transferring it back to another 5 gallon? Do I rack it off the cherry remains at all?).

Thanks in advance for any feedback.

The cherries alone will probably take up about 1-1.5 gallons (depending if you go for 10 or 15 lbs), plus you need some room for fermentation. I would say a 7 gallons would be the minimum. I like to leave fruit in contact with my sour for months up to a year (depending on the fruit). A 7 gallon bucket would be about the right size, but it might be a bit more oxygen permeable than optimal. Good luck.

Thanks for feedback.

I've been reading your blog for a while now, so I've got some confidence in the source. I also just noticed your write-up on turbid mashing (timely). Nice way to spend 10 hours, huh? I'd love to see an exercise where a similar grain bill and fermentation plan are employed with the only variable being the turbid mash to understand its effect.

I'm leaning towards using a 6.5 gal glass carboy. Using a bucket scares me due to the O2 permeability during a long fermentation.

Perhaps I'll start by adding 10lbs of cherries and the beer, then see if I can fit any more fruit. If it won't fit, I'll just have to add the leftover fruit to some other beer.

Id say add half of the cherries and all the beer to a 6.5 gallon carboy, wait for the fermentation to Chill out a bit and add the rest a couple cups at a time slowly (over a couple weeks) so you dont lose too much beer to the blow off.

Sounds like a solid plan. I have half my lambic from last summer sitting on a combo of raspberries and dark cherries.

The problem with any experiment involving sour beer is that there is so much variation barrel to barrel or carboy to carboy even given identical methods. You would almost have to do 5 batches with each mash and see what similarities/differences each set developed.

I usually add 1 pound of fruit per gallon of beer, and use a 6 gallon carboy for 5 gallon batches. I usually lose about a half gallon to the fruit when bottling it, unfortunately.

I just bottled my merlot lambic that I brewed in May '08. I put grapes on it in March of this year. It's awesome! It was clear enough that I didn't have to move to tertiary but I did filter the auto-siphon.

Given that traditional lambics aged in wood, why would the oxygen permeability of plastic be a problem?

plastic is more oxygen permeable than an oak barrel, especialy a huge foudre.

Orangevango said:

plastic is more oxygen permeable than an oak barrel, especialy a huge foudre.

Click to expand...

The pellicle acts as a nice "lid" and keeps oxygen out. One of my lambics has been in a bucket since november.

Orangevango said:

Id say add half of the cherries and all the beer to a 6.5 gallon carboy, wait for the fermentation to Chill out a bit and add the rest a couple cups at a time slowly (over a couple weeks) so you dont lose too much beer to the blow off.

Click to expand...

This is sorta how I do it. I split the batch in half and just let the cherries ferment for a week or so till most of the action stops and then I just fill it back up with the rest of the beer. You wont lose any beer that way

here is the split with 8lbs.


and here it is full on the lower left. That's 8 lbs of cherries and 6 gallons of beer in a 6.5 gallon carboy and its about as full as it gets

The pellicle doesnt enter into it. Its permeability through the walls of the bucket. Here is a list of oxygen permeability of different aging vessels taken from page 220 of "Wild Brews" by Jeff Sparrow.

• Rodenbach Foudre (20,000 liters): 0.53
• Rodenbach Foudre (12,000 liters) : 0.86
• wine barrel (300 liters): 8.5
• Homebrew oak barrel (40 liters) : 23
• homebrew bucket (20 liters) 220
• glass carboy with silicon stopper (20 liters): 17
• glass carboy with wooden stopper (20 liters) : 0.10

The number after the colon is the cubic centimeters of oxygen per liter per year.

The list is abreviated.

As you can see, plastic is MUCH more permeable than wood. Oxygen leads to acetification.

I learned about this the hard way. I had to dump my 10 gallons of lambic that was sitting in plastic.