Sorry i cant help you out wth the gallon thing being from Australia, however i can tell u what i do.
I make 2 days worth at once. 3lts a day (and drink between 2.5 to the whole 3lts, which is about 6-12 glasses) i store it in 3x2lt old coke/pop bottles.
To make 3lts i use 400mls of mayple, 400mls lime/lemon juice and add 2.5lts of water. I mix it all up in a big pot then shake alot of cayenne on that, and transfer it to the bottles. Works well for me.