No, but it was once widely thought that summertime thunderstorms could cause fresh milk to curdle.
This thinking was based on observations that raw milk would spoil during lightning and thunderstorms. But it was neither the thunderstorms nor lightning that caused the spoiling; rather it was the atmospheric conditions. The conditions that are optimum for thunderstorm development are the same as those that would cause milk to spoil.
Milk curdles because of bacteria, not because of thunderstorms. Microbes in milk consume the milk’s natural sugars and produce lactic acid as a waste product. This coagulates the milk’s proteins, resulting in lumps in the milk and making the milk taste sour. Bacteria thrive in warm, humid conditions, so hot and humid days were particularly troublesome to early dairy farmers. These same atmospheric conditions are also favorable for summertime thunderstorms.
Thunderstorms require warm moist air that rises, so the environmental conditions that support thunderstorm development are like those in which milk can spoil. This similarity led to the observed correlation of milk spoiling during thunderstorms. But the conclusion that the thunderstorm caused the milk to spoil was incorrect.
An article in the journal Science in 1891 by A.L. Treadwell may be the first to suggest that milk spoils because of bacteria. In 1927, E.H. Farrington published an article that summarized his experiments and noted that “sultry atmosphere usually precedes thunder showers and provides favorable conditions for the growth of milk-souring bacteria.” Part of his career included a professorship at the University of Wisconsin, where the paper was published. “Sultry” is typically used to describe summer stretches of warm days and nights with high dew points.
Pasteurization and refrigeration prevent the milk from spoiling, as they make environments that are too hot or cold for bacteria to thrive. We have not developed the technologies to prevent thunderstorms from developing.
Steve Ackerman and Jonathan Martin, professors in the UW-Madison department of atmospheric and oceanic sciences, are guests on WHA radio (970 AM) at noon the last Monday of each month. send them your questions at stevea@ssec.wisc.edu or jemarti1@wisc.edu.
