The bacteriological standard has proved of value in determining the purity of milk and controlling its supply. Is the counting of bacteria in ice cream equally valuable in determining its wholesomeness and regulating its manufacture?
The very great numbers of bacteria generally found in ice cream, in Iowa and elsewhere, make this question important, but it is hardly possible to answer it positively at present. However, in the investigations made by the Iowa Agricultural Experiment Station and set forth in this bulletin these facts appeared:
As cleanliness in making ice cream increases, the number of bacteria decreases. It is possible to make ice cream in quantities up to 20 gallons with a low bacterial count without expensive methods, though it is not certain that this is true under large factory conditions. When ice cream is properly hardened its bacterial content will not increase in storage. The chief source of bacteria in ice cream is the cream, although gelatin may add large numbers and the freezer is likely to be an important source of contamination.
Hammer, B. W.
"Bacteria and ice cream,"
Bulletin: Vol. 11
, Article 1.
Available at: https://lib.dr.iastate.edu/bulletin/vol11/iss134/1