Don't think of Better Bottles as plastic- think of them as flexible glass, because they are made from a special, scientifically tested PET, which does not have all the disadvantages of other plastics. Better Bottles are 1) Unbreakable 2) Taste and odor free 3) Impermeable to air 4) Clear and colorless 5) Incredibly light weight 6) Stain resistant. They have wide precisoin openings for which leak-tight, non-jamming closures are available. Optional, adjustable outlets make dispensing or racking by gravity simple and convenient. If you don't wish to use Better Bottle accessories, you can use a #10 drilled or solid gummed rubber stopper.