A simplified screening test is described for estimating the bacterial population of Grade A milk. The method employs an anchor-shaped dipper for measuring and sampling milk from the weigh-vat. The sample is transferred directly to prepared dilution bottles. A 0.01 ml milk transfer loop is used to inoculate 3 ml of agar in a 1-ounce screw-cap bottle. The bottle is laid on its side, incubated 48 hours, and the colonies counted. The number of colonies multiplied by 5,000 yields the bacterial estimates. Results compare favorably with the Standard Plant Count.

This content is only available as a PDF.

Author notes

Mr. Burdet Heinemann was born in St. Louis, Missouri. He was graduated from Iowa State College receiving a B. S. degree in bacteriology. He has been associated with Producers Creamery Company of Springfield, Missouri, since 1936, and is now Technical Director of that organization. He is the author of a number of publications dealing with analytical methods for dairy products. He is a member of the International Association of Milk and Food Sanitarians, Inc., the American Chemical Society, and the American Dairy Science Association.