Can a keg be too big?

Hi all.

A friend of mine has a couple of old Sanke 7.75 gallon "Pony kegs" he is willing to give me. I was wondering if it's a problem to only put 5 gallons of beer in, or if I need to make bigger batches to fill them up.

If anyone has any knowledge about this, I'd be very grateful.

You could put 5G in with no issues.

Understand though that most people use corny style soda kegs for homebrewing as they are easier to clean, fill, etc...

I know that regular style kegs can be filled, but not able to provide much more than that.

well assuming you carbonate in the keg and burp it once or twice to get some of the 2.5 gallons of air out i cant see a problem. after the burping there would be a layer of protective CO2 on top to prevent oxidation.

I use sanke kegs and can tell you that those 7 3/4 gallon kegs are great for fermenting 5 gallon batches! As for serving in them, there are no issues that I've run in to. If you need help pulling the spear out let me know and I'll give all the help I can. Once you've done 2-3 it's very easy!

Definition of a keg that is too big:

A keg that:
1) is too large for you to move
2) you are unable to refrigerate
3) has a bottom so large that you cannot brew enough beer to get the volume high enough to allow the dip tube to pull it up to the tap.

I'd use them as fermenters... if you're going to use them for serving- and especially if you'll be using them for force carbing- that is a lot of dead space you'll have to fill up with CO2 every time that you won't get anything for.

Either that or step up your other equipment so you can make 6 or 7 gallon batches!

Thanks everyone. Yes, I looked at getting a 'corny' setup, but then I saw the price. As another friend of mine saws. "Free's a pretty good price. You can't beat free."

He's basically going to lend/give me eveything I need to keg and serve beer. An offer I would struggle to turn down. Even if I only use them until I can afford corny's (assuming I don't get on with the sanke's) I figure it'll be better than bottling.

If I do change I guess I could then use them as fermentors. Hmm, or I could just ferment in one and rack to the other, then i would be able to produce the full 7.75 gallons. Of course I'd have to concentrate the wort so I could add water, but at the moment I'm having to do that anyway.

I was planning on using natural carbonation, I guess I'll have to put in extra sugar to allow for all the extra space. That's something I'm going to have to experiment with I guess.

Special thanks to kornkob for that answer, it made me chuckle.

wyzazz, you may well be hearing from me some time in the future with a few questions.