I hope I have my terms right. I am wondering if someone has tried putting a balloon on the top of their fermentation vessel in order to capture the CO2. I’m thinking about trying it so that when I dump the yeast I don’t suck in any oxygen.
Thoughts? How big of a balloon do I need?
Dumping yeast, it must be a conical… why not put a corny gas in post on it? When it’s time to dump yeast, you’d only need a couple psi of CO2 to keep air out.
^^^^
THIS
Have we considered the oxygen permeability of a balloon? 8)
Hi Jim. Yeah I have one of those ball lock pressure relief tri clamp fittings that I have used previously. I’m just tired of buying CO2.
How 1920s!
It should only take a little dab of CO2
I remember my dad having balloons on his carboys back in the 60s 70s. I think he started with blow off tube, then when the bubbles stopped he put on a big balloon. It must have been something you got at the beer/wine supply because I’m pretty sure they fit over a carboy. Long time ago though… who knows. He mostly made wine.
The volume of CO2 produced Steve would depend on the volume of beer and how many gravity points of fermentation you get. I’d imagine you could use a kraeusening calculator to get a close guess.
I have some monster balloons we used to use for advertising big sales, until the price of helium went sky high, no pun intended. Fully inflated they were about 6 feet in diameter, and IIRC filling 3 of them consumed an entire 100 lb. bottle of helium - at $100 per refill. The point of this is that filling a balloon will generate some fairly substantial pressure, you might try a lawn and leaf garbage bag first, I think they are about 40 gallons. I attach a trash bag filled with CO2 to the airlock port now when bottling, just to minimize air entering the conical as it drains [laugh if you want].
Each gravity point of fermentables consumed produces ~0.5 volumes of CO2. A quick back-of-the-envelope calculation for an average-gravity beer:
1.050 OG - 1.010 FG = 40 gravity points consumed * 20 liters (batch size) * 0.5 volumes per gravity point = 400 liters of CO2
You’re going to need a rather large balloon, methinks
Wow. Never mind!
Hmmm… seems overthought to me. If you’ll dump a quart of yeast (or half gallon of yeast) then you’d simply need a quart volume of gas co2 (or half gallon volume of gas co2). Otherwise, not much. Seems like you could capture that much in a balloon in a day at the tail ends of fermentation, but canned co2 seems like a much easier option.