Bob asked if plastic containers designed for use with milk contain an ingredient to retard spoilage. Presumably, this would be a bactericide. I spend quite a few years in the milk/juice packaging industry. This is a huge industry involving high speed very sophisticated equipment packaging everything from one ounce creamers to two gallon jugs of juice. The lines move so fast that one literally cannot see individual creamers being filled and sealed, and they do this in almost sterile conditions! There are several different kinds of plastic used for milk. The least expensive is PET (I forget the full name), and PET (in the presence of light) will definitely affect the taste of the milk. The most expensive is polypropylene, and that is used for returnable containers as well as on the inside of milk cartons. Polypropylene will not affect taste. Other types of plastic are used as well, and all will affect taste somewhat, but not as bad as PET. However, none of the plastics contain anything to kill bacteria. I am quite certain that this would not be permitted by the FDA. Bacteria is killed in processing plants by either pasteurization or ultra violet lights. Neither kills 100%, but properly maintained both will kill more than 99.5%, and plants often shoot for 99.9%. Lloyd Mailto:[log in to unmask] Lloyd Spear Owner, Ross Rounds, Inc. The finest in comb honey production. Visit our web site at http://www.rossrounds.com.