The world is full of folk wisdom and old wives’ tales. Today I learned an old wives’ tale originating in Russia: Putting a frog in milk will keep it fresh longer.
Prior to pasteurization and refrigeration, keeping milk fresh was a serious challenge. Bacteria can multiple quickly in room temperature milk. Even with pasteurization, present day food safety guidelines recommend not allowing milk to sit out of the refrigerator for more than two hours.
Why Russian peasants believed that a frog could keep milk fresh is unclear. One thought is that frogs are cold and clammy to the touch, so perhaps they hoped the frogs would transfer that property to the milk. Another idea comes from the practice of submerging the containers of milk in a spring or stream to keep them cool. If the containers were uncovered this would inevitably result in frogs in the milk. Perhaps people began to attribute the prolonged freshness from the cooler temperatures to the frogs.
On the other hand, perhaps this particular myth has some truth in it. In 2012, organic chemist A.T. Lebedev and colleagues at the Moscow State University published research in which they had found 76 peptides on the skin of the Russian brown frog in addition to the 21 that had previously been identified. These skin secretions on the frog form a protective layer against the many microorganisms found in a frog’s natural habitat including potentially harmful bacteria. In laboratory testing some of these peptides were as effective against Salmonella and Staphylococcus as some prescription antibiotics.
The idea of frogs keeping milk fresh may not be as farfetched as it seems at first glance, but it is certainly not a recommended or safe practice. Also, it just sounds gross. I have no desire to drink frog-infused milk. I do find it fascinating though that researching such a ridiculous old wives’ tale could lead to the discovery of potential new and important antibiotics, and I wonder what else might be learned by investigating other myths.
Crystal Kelly is a feature writer for Bizarre Bytes with those unusual facts that you only need to know for Trivial Pursuit or Jeopardy or to stump your in-laws.
