+1 on the storing in mylar bags. Also its a good idea to use food grade buckets with oxygen absorbers inside of both the bucket and the mylar bags. If you have any big chain grocery stores around, one day go in and talk to some of the bakery people and see if you can score some, they should have the ones that icing and stuff come in, cause most of the time they just throw them out. Using 2 liters really isn't a safe way, over time light gets to the food and the plastic slowly degrades letting in air and moisture.
Charles.