Filling corny kegs by weight? (closed system fill technique)

[sleepystevenson]

Hey all -
I started filling my cornies by pushing the beer out of the (2) half barrel sanke keg fermenters sitting in the fermentation chest freezer with CO2. No trying to lift out one of those suckers out and disturb it and shake up the sediment in a fermentor that has already been chilled and "cleared". Well, up to this point, I have just been opening up the top of the corny, tossing in the sanitized transfer hose and transferring, filling from the bottom with a couple lbs of gas pressure.

I was thinking about how I could go for a completely closed system (well, minus opening the center vent) technique by filling though the black "beer out" ball valve. I got the idea of filling by weight: Set the corny on a bathroom or other scale and then stopping at a previously determined weight, (5 gals. + corny weight +/-) thereby eliminating entirely the need to take the lid off the corny.


From what I have learned from my HBT searches:
Water weighs about 8.35 Lbs per gallon
Saw a thread here that stated that Beer weighs around 8.8 lbs per gallon, but no hard data there. ( I would think it would be much closer to the 8.35 lbs -taking the weight of the water x the FG, even at a high FG of 1.020, is only 8.517 Lbs...)

Empty corny weight is 8.45 lbs - just checked it on our very accurate scale here at work. Say, 8.5 lbs.

So, if you figure about 8.5 lbs per gallon of beer and 8.5 lbs for an empty keg, you're looking at 51 lbs. total for a filled corny....APPROXIMATELY of course.

Anybody else use this method? If so, any advise - especially in regard to the weights?

I searched here on HBT, but couldn't really find anything....and I KNOW I can't be the first to use/attempt this method.

Thanks! And Happy Holidays, brewers!

 

[Ace_Club]

Sounds like a good way to go. Your best bet, instead of the calculations, would be to fill an empty corny the regular way and then weigh it full to see what your result is. This will serve to verify your initial calculations.

Keep us posted with the results.

 

[RogerMcAllen]

Sounds like that will work just fine, in tandem I have two suggestions that have worked out well for me:

1. The beer will be cold, you should just be able to put a finger on the side of the room temperature keg and feel the level of the cold beer.
2. Instead of using the pressure release, use the gas out post. Take a gas QD and unscrew the gas tubing. Hold a towel over the end, and press it down gently onto the gas post to depress the poppet (DO NOT SNAP IT INTO PLACE) to vent gas. You will get a bit of foam in the receiving keg, so you will start to hear the foam get sucked up into the gas post when it reaches the top of the keg. If you have no foam, the towel catches a quick squirt of beer.

 

[Scut_Monkey]

Sounds like a good way to go. Your best bet, instead of the calculations, would be to fill an empty corny the regular way and then weigh it full to see what your result is. This will serve to verify your initial calculations.

Keep us posted with the results.

I would do this as well and I would also be interested to see what the difference is between a keg full of beer and full of water. I'm interested to see what your results show. It sounds like a cool idea to me.

 

[bja]

Sounds like that will work just fine, in tandem I have two suggestions that have worked out well for me:

1. The beer will be cold, you should just be able to put a finger on the side of the room temperature keg and feel the level of the cold beer.
2. Instead of using the pressure release, use the gas out post. Take a gas QD and unscrew the gas tubing. Hold a towel over the end, and press it down gently onto the gas post to depress the poppet (DO NOT SNAP IT INTO PLACE) to vent gas. You will get a bit of foam in the receiving keg, so you will start to hear the foam get sucked up into the gas post when it reaches the top of the keg. If you have no foam, the towel catches a quick squirt of beer.

+1 I've been doing it this way for years, but I do snap a gas post in place and just yank it off real quick when I hear the foam coming.

 

[sleepystevenson]

thanks for the replies and ideas, guys. I am gonna give it a try in the next couple days, and will report back.

As was stated earlier, the beer is very cold-34 - in the fermenters, so it will definitely leave a condensation line on the kegs as they fill, as a visible level indicator. I think I will just take the lid off the keg for the first one when I start getting close to full, just to watch the progression. Never had a problem filling them with the lid off before, so no worry that way! Also, while I am cleaning/sanitizing the kegs to fill, I will fill one up with water, just to get an estimate on the weight before beginning the beer fill. Maybe use an old ale pale with gal markings to get an approximate 5 gals in the keg.

 

[Brewfat]

No need to fill and weigh. Just weight an empty keg and add 42 lbs (1.01FG, 5 gals, 8.34 lb/gal at 32F).