In most cases, drinking expired milk will result in food poisoning. Always be sure to check your expiry date and smell your milk prior to drinking.
Expired milk gets its characteristic pungency from lactic acid, which is formed by the presence of lactobacillus bacteria. While the odor of expired milk should be enough to put anyone off of actually drinking it, it isn't the end of the world if some happens to be accidentally swallowed. Expired milk can be dangerous to children and adults with weak immune systems, but for most adults, the worst it will do is most likely give a case of mild food poisoning, with symptoms including stomach cramps, nausea, fever, and diarrhea.
The reason that expired milk isn't as dangerous as people may think is due to the process of pasteurization used in producing milk. Pasteurization requires using heat sufficiently hot enough to kill most of the bacteria present. Some bacteria, however, are able to survive the process. Milk actually "goes bad" when this bacteria (lactobacillus) converts the lactose present in milk to glucose and galactose, forming lactic acid.
It should also be noted that milk is often safe to consume a couple days past the printed expiry date, so if you have a glass of milk on Tuesday and see it expired that previous Monday, don't panic. While expired milk isn't usually dangerous - apart from some discomfort - it can be harmful to those with weak immune systems and does not impart any benefits to your health.
The best thing to do is check the expiry date and do a sniff test. If something seems off about the milk, discard it.
Possible short-term side effects
- fever vomiting
- stomach cramps
Ingredients to be aware of
- lactic acid
- lactobacillus bacteria
- milk that hasn't spoiled
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Written by Jeff Volling | 12-28-2015
Written by Jeff Volling
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