5# co2 bottle, how long?

I have kegged 7 beers total since I began. The scale that my tank sits on says that I've used about 1 lb of CO_2 so far.

 

I figure you can get around 7-10 kegs from a 5 pound bottle.. Thats involved in using it to push starsan through the keg when you clean it, and the lines. Use it to purge the kegs before you rack into them, and venting and purging the keg after filling, and between dry hopping.

Haven't really kept track. Co2 isn't mind boggling expensive, so I'm not too tight with how I use it. I also use it to purge some bottles, and use it to put a co2 blanket in carboys/buckets of beers that I'm aging and have a little headspace, and in beers that you don't want any oxygen into, like a sour mash.

 

I usually get about 6-8. It depends on what you use CO2 for. I purge all my kegs for storage with CO2 to make sure they are pressure tested. Slow and steady won't save CO2. It's dissolved into beer, or it's taking up head space. The gauge for the tank is not reliable and might hold up until you get to your last 5 or so pints. Then it hits zero and you'll have to refill.

I just filled at a fire/security store for $11 and about 20 minutes of my time. If you can't find a good price you can always carb with table sugar and move the beer through your lines with CO2. Usually it's 6 one way and half dozen the other on cost.

 

OP: Now that you're 'all in' for kegging, I'll let you in on a secret. You never know when a tank is going to run out. You need a backup tank.

 

OP: get a 20# tank and use the 5# for backup

 

How about the approach alluded to by utahbeerdude (weighing the keg)? I never thought of it but it seems like it could be a solution.

 

I have 4 tanks. Like Vikeman said, you never know when you are going to run out. I was carbing 2 kegs to take up to deer camp and to my horror when I went to pack my tank was empty. I had a very slow leak in one of my kegs that drained me. I would have been very unhappy to have not been able to serve my beer at camp! Good luck with your new kegerator!

 

That can work, if you're certain of your tare weight, and if the scale is good. But you still need a backup tank unless you're willing to accept down-time when it's time to exchange/refill.

 

I started with a 20# tank and thought I'd get a 5# spare. Instead, I got a second 20# tank. If you shop around, you can probably find one for the same price as a 5#. I can now go about 5 years and maybe 50 kegs between refills. That's purging, force carbing, serving, moving cleaner/sanitizer, etc. (IOW, I'm not shy about using it)

 

I Just got done kegging and carbonating my 4th homebrew and now I have SN Celebration on tap. Still feels like it has a good amount left in there. Depending how much it gets used in this upcoming week, I might trade it out before thanksgiving, just in case. Would hate to run out then.

 

The gauge is not reliable only if you're expecting it to tell you something it's not designed to tell you.

It's a common misconception that the gauge indicates how much CO2 is in the tank. It doesn't. But, more importantly, it doesn't try to. It only tells you the tank pressure, which, in the presence of liquid CO2, is constant at a given temperature. Whether it's a full tank or a single drop of liquid, the gauge will read 700-ish psi at room temperature (I don't recall the exact number). In that sense, it's a binary indicator - you've got liquid CO2 or you don't. I suppose it could be argued that, between zero and 700psi, it's still telling you something - that you don't have enough CO2 for tonight's party (IOW, it's not empty, but it might as well be).

The only practical, reliable way to know how much CO2 is in the tank is to weigh it. Subtract the Tare Weight (look for TW among the forest of numbers embossed on the tank) to determine how much you've got.

 

I get around 10-12 batches for a 5# tank, assuming no leaks. Force carb. Have a full back up on hand. I usually only have to do a swap once a year, give or take.

 

I have 4 taps and 2 bottles with splitters. My 5#ers last about 9 months, but my 20# one I use for purging/bottling is going on 2 years. Currently have 1 extra 5#er.

 

The system I envision is exchange tank for full one, weigh it, reweigh it periodically to learn by difference how much you used. It should be a decent guide. But I see your point about the back up tank, and if you have that piece of mind, maybe being able to estimate how soon you need to change tanks is not a big concern. Back up tank makes my list of 2014 homebrew upgrades.

 

They're like propane tanks. It doesn't matter what size they are, and it's nice to have more than one.