Mylar Balloon for CO2

[A1sportsdad]

So I am getting ready for my first real keg of beer. Just finally getting everything together for my Keezer. I plan to cold crash in my fermenter (it's a plastic Big Mouth Bubbler). So I don't suck back Star San or air, I plan to do the mylar balloon trick. I'll fill mine from a line off the CO2 regulator since I didn't have it connected during fermentation to fill if from the fermenter. Now in calculating the amount of CO2 I will need. It's surprisingly small if I am doing this right. I would think this is just an Ideal Gas Law calculation with pressure constant, so the volume change is inversely proportional to the temperature change (in degrees Rankine). I'm looking at about a 33 degree drop, so in Rankine I'm looking at about 495/528, so the head space volume would go down to about 94% of original. I'm looking at about 1 1/2 gal of head space, so we are only talking about losing about 0.1 gal. That easily fits in a single balloon.
Does this sound right. Somehow in my mind I was expecting a much larger volume collapse.

Thanks

 

[A1sportsdad]

Well, I finally got to cold crashing my Brown Ale. I filled a Mylar balloon with CO2 from my tank then connected that to the blowoff tube. Put it in my fermenting fridge and set it to 34 F. After 26 hours it’s cooled from 68 F to 35 F and the Mylar balloon is still partly inflated. All good. First time cold crashing. I’m thinking I should give it 3 days at this temp then transfer to the kegs. First time kegging as well.

 

[Immocles]

I bought 2 cold crash guardians from brewhardware and love them. Mylar balloon works well too, but I liked having all the pieces I need in one go. With the larger gas bladder, im able to crash and transfer a 3G batch into my keg. If I ever buy a third fermenter, I will immediately buy a third CCG.

 

[Brooothru]

I bought 2 cold crash guardians from brewhardware and love them. Mylar balloon works well too, but I liked having all the pieces I need in one go. With the larger gas bladder, im able to crash and transfer a 3G batch into my keg. If I ever buy a third fermenter, I will immediately buy a third CCG.

I hear that China has launched a new product that might be of interest, and apparently it's a real high flyer. I think this trial balloon might be a bit large for a home brew application. But before anybody shoots my idea down....

Too soon?