If it's just for a week or two, a ziplock bag works well. Close it most of the way, deflate it and then seal it the rest of the way. I usually test my bags (close them with air inside, press on them and see if air leaks out from any tiny holes) before trusting them for long-term use. A ziplock in a gladware/tupperware will last for at least a month pretty much good as new, in my experience.