Imagine a world where beer was our currency. The value of standard bottled beer would break down something like this:
8 oz.: $1
12 oz.: $2
16 oz.: $5
22 oz: $8
32 oz: $10
40 oz: $20
Certain beers would have a reputation as top-notch, so they would be traded or invested in like gold, with a constantly flucuating value margin. Can you see yourself walking into Albertson's and trading a 32-ounce bottle of Pliny the Elder for today's $50 worth of groceries? I can! Albertson's could then place that beer either back on the shelf or purchase its supplies with it.
Each homebrewer's quality of beer would be graded twice a year, putting a different value on your larger bottles. Imagine the amount of different beers grocery stores would have available for you!
OK, so you wouldn't exactly have a "wallet" for these brews, so I guess you'd still need a beer bank. And, eventually, those bank owners would start loaning out your beer to those who can't get good beer, for which they'd have to return to the bank with an interest of even more beer, probably crappy beer already owed to other people, at that. Then, a private company would no doubt come in and take over because some beer was worth more than other beer, and it would become the Beer Reserve. After that, there will be a time when everyone pulls all of their beer out of their beer banks, and because the beer banks had loaned out too much of their beer, there wouldn't be enough beer for everyone to get their own beer. This, in turn, would then lead to the great Beer Depression because the Beer Fed would stop paying the smaller beer banks with more beer.
Never mind, maybe paying for things with beer is a bad idea.