Mini Kegging System - For One Gallon Batches

See:  DIY Keg Pressure Release Valve System

Rectangular container for the aging of alcoholic beverages

Ever wondered if a square keg would work?   This clever patent shows that it can be done.  No indication how much pressure it could safely handle. It would need to stay less than 5 ATM with a good pressure release valve and be safely tested first.

You can take a closer look at the following link to *US4093099.  1 cubic foot holds 7.48 gallons or 28.3 liters.  4 cubic decimeters or about 12 inches equals 4 Liters.

*Always respect patents. 

Here is a good article: Oak Barrels, will they hold pressure? - Home Brew Forums

Cheers!