I've always used a plastic flask you can get at any Walmart in their camping section. Comes with a one ounce jigger on top and very lightweight. I've had alcohol stored in it now since 2009 and no deterioration. Not sure why I would need a 'backup' one ounce of alcohol. Maybe if you were using it for an emergency bag in your car, but I don't see an application for backpacking here.