[maus42]

>* Freezing meat twice and eating it will make you sick

Uh, every frozen meal I have ever seen has come with the printed warning not to freeze it again after it has melted?

Freezing does not kill microbes, and additionally formation of ice during the freezing breaks the internal structure of foodstuff making it better medium for bacterial growth. So repeated freezing-unfreezing, especially if the product is taken into room temperature and back allows unwelcome microbes to proliferate. Like with all food poisoning hazards, it will not make you sick with 100% certainty, but increases the risk enough that it is not recommended.

This is near word-by-word translation of the guidelines of Finnish medical society [1] and food safety authority [2].

It is difficult to call "do not freeze stuff again" an unfounded superstition equal to fan death if it is the common recommendation by national authorities.

[1] https://www.terveyskirjasto.fi/terveyskirjasto/tk.koti?p_art...

[2] https://www.evira.fi/elintarvikkeet/valmistus-ja-myynti/elin...

[teekert]

Ok I didn't consider the "makes meat more permeable to bacteria" -argument. Still, bacteria do die from repeated freeze-thawing cycles. But, in any case, I doubt many people ever investigated the scientific evidence.

[coldtea]

>Ok I didn't consider the "makes meat more permeable to bacteria" -argument. Still, bacteria do die from repeated freeze-thawing cycles.

Not really. They multiply during the thawing and lie "inactive" during freezing. So repeated freeze-thawing cycles = several generations more bacteria than you started with.

Bernhard Redl, an associate professor in the molecular biology department at the University of Innsbruck in Austria:

"It is clear that freezing does not kill most of the bacteria," said Redl, "but puts them in a dormant state." (...)