7 ms·

I got a good one the other day. I searched "does freezing kill bacteria", and the featured answer came back "freezing food kills harmful bacteria that can cause

I got a good one the other day. I searched "does freezing kill bacteria", and the featured answer came back "freezing food kills harmful bacteria that can cause food poisoning". I was curious, so I clicked through to read more. It turns out this text was taken from the headline at the top of a PDF. What the Google crawler didn't notice, however, was that the headline actually had another headline above it. The full text read "Myth: Freezing food kills harmful bacteria that can cause food poisoning".

pvaldes 6y ago
This was accurately fixed. Freezing definitely kills most types of bacteria
- umvi 6y ago
  Which, I'm assuming, is why all sushi in the USA must must be frozen and then re-thawed before serving.
  - yawz 6y ago
    Really!?! I had sushi at the bar many times and it was prepared right in front of me. Maybe you meant ingredients?
    - snug 6y ago
      Sushi grade fish must be flash frozen to kill any bacteria, worms, etc. in order to be served frozen. Most fresh (killed, butchered and served quickly) food isn't really great, either taste wise or health wise. Especially if it's not fully cooked. Most red meats sit out for a bit, either wet or dry aged, which enhances the flavors. Fish will need to be frozen or cooked to a safe temperature.
      - winter_blue 6y ago
        I knew someone (a French person) who was a massive fan of tartare. Tartare is basically raw meat. He'd go to expensive tartare restaurants (in Paris), where hygienically-raised cows were killed, and the meat cut out and served, all in the same day. He described tartare as being the best thing ever. (I've never tried it.)
        ska 6y ago
        This is really more common than many north americans think. Crudo, tartare, carpaccio, sashimi, etc. Cow, fish, horse, buffalo, etc. Some are raw & seasoned, some lightly cured (e.g. ceviche)
        louhike 6y ago
        I'm french and yes "steak tartare" is quite common in restaurants (mostly in what we call "bistrot"). There is often a raw yolk on top.
        btilly 6y ago
        I have tried it by accident. It was delicious...but if I ate it too fast I would gag.
        yawz 6y ago
        Yes, seeing there "steak" and ordering it without knowing it's "raw" is a very common mistakes for tourists in France.
        PixelOfDeath 6y ago
        In Germany and surrounding countries it is very common to eat raw minced pork meat (Mett) on bread/buns.
        dhimes 6y ago
        I seem to recall this was breakfast fare.
        6y ago
      - deleted 6y ago
        [deleted]
      - majkinetor 6y ago
        Tartare should be kept bellow -18 for at least 3 days as far as I know. You should never eat it fresh.
      - munificent 6y ago
        > Most fresh (killed, butchered and served quickly) food isn't really great I have eaten raw skipjack tuna that I caught myself and never froze. Tuna, as far as I know, has very little risk of parasitic infection. It was delicious.
        Baeocystin 6y ago
        Unfortunately, tuna carries a high parasitic load, including parasites that can affect people: https://pubmed.ncbi.nlm.nih.gov/25461601/ https://pubmed.ncbi.nlm.nih.gov/25461601/ https://www.healthline.com/nutrition/raw-tuna#parasites https://www.healthline.com/nutrition/raw-tuna#parasites You got lucky, and yes, it is delicious, but you're definitely playing health roulette.
        munificent 6y ago
        Yeah, it's not necessarily something I'd do again knowing what I know today. Thank you for the links. :)
        pvaldes 6y ago
        Is not the worst fish in this sense. Cod is worse. The real problem with tuna is that is an accumulator of nasty substances like mercury and also fast and nomadic by nature. This means that you can find Japanese tuna in California, or the Mediterranean, and this can be a problem. Most of the fish parasites just turn into food after being cooked. Our stomach acid will not care. The number of marine fish parasites able to harm humans is very small. We are too hot for them. I could count all the major types with my fingers (I was surprised to learn (here) that Kudoa is a new problem in any case).
    - umvi 6y ago
      Yes, if you had sushi in a restaurant in the USA, the fish was frozen and re-thawed beforehand. https://cooking.stackexchange.com/questions/76455/in-the-usa-does-fish-being-served-raw-need-to-be-frozen-first https://cooking.stackexchange.com/questions/76455/in-the-usa...
  - pvaldes 6y ago
    This is for roundworms. Is a different problem.
- verylittlemeat 6y ago
  Unless I'm missing a joke or something I just googled it and it says freezing only makes bacteria inactive. https://ask.usda.gov/s/article/Does-freezing-food-kill-bacteria https://ask.usda.gov/s/article/Does-freezing-food-kill-bacte...
  - pvaldes 6y ago
    Freezing is lowering the temperature below zero Celsius. In anything made of water, the procedure creates ice crystals that poke the cell membrane, making a lot of microscopic holes than quickly leach the inner contents of the organism by differences in osmotic pressure. This kills the cell by "bleeding to death". As bacterias are cells with membranes in principle they are killed when frozen, so far, so good... ... but this is just the general case. Not all bacterias have being created equal and there are thousands of species. Some are extremophiles and store sugar or other substances that act as an antifreeze, so can decrease the temperature of freezing and remain "liquid" under zero point. They can stand much lower temperatures before being killed (by freezing). Is just that they are killed at -25C instead -5C, but the killer is still a tiny ice dagger. And some bacteria have evolved an outer protective gelatinous capsule, made partially with "sugar", that is not easy to pierce, so they can alter their osmotic pressure and stand more osmotic stress. And finally, some will just die, but not before creating a inner spore devoid of water that can stand the cold or dry until rehydrated. No water, no ice.
    - verylittlemeat 6y ago
      Wow I definitely wasn't expecting such a detailed explanation. Thanks :)
      - wayneftw 6y ago
        Maybe next time somebody googles it they will find this explanation.
        laksdjfkasljdf 6y ago
        Chance is close to zero as google weight by links. and nobody links to comments.

pvaldes 6y ago

This was accurately fixed. Freezing definitely kills most types of bacteria

umvi 6y ago
Which, I'm assuming, is why all sushi in the USA must must be frozen and then re-thawed before serving.
- yawz 6y ago
  Really!?! I had sushi at the bar many times and it was prepared right in front of me. Maybe you meant ingredients?
  - snug 6y ago
    Sushi grade fish must be flash frozen to kill any bacteria, worms, etc. in order to be served frozen. Most fresh (killed, butchered and served quickly) food isn't really great, either taste wise or health wise. Especially if it's not fully cooked. Most red meats sit out for a bit, either wet or dry aged, which enhances the flavors. Fish will need to be frozen or cooked to a safe temperature.
    - winter_blue 6y ago
      I knew someone (a French person) who was a massive fan of tartare. Tartare is basically raw meat. He'd go to expensive tartare restaurants (in Paris), where hygienically-raised cows were killed, and the meat cut out and served, all in the same day. He described tartare as being the best thing ever. (I've never tried it.)
      - ska 6y ago
        This is really more common than many north americans think. Crudo, tartare, carpaccio, sashimi, etc. Cow, fish, horse, buffalo, etc. Some are raw & seasoned, some lightly cured (e.g. ceviche)
      - louhike 6y ago
        I'm french and yes "steak tartare" is quite common in restaurants (mostly in what we call "bistrot"). There is often a raw yolk on top.
      - btilly 6y ago
        I have tried it by accident. It was delicious...but if I ate it too fast I would gag.
        yawz 6y ago
        Yes, seeing there "steak" and ordering it without knowing it's "raw" is a very common mistakes for tourists in France.
      - PixelOfDeath 6y ago
        In Germany and surrounding countries it is very common to eat raw minced pork meat (Mett) on bread/buns.
        dhimes 6y ago
        I seem to recall this was breakfast fare.
        6y ago
    - deleted 6y ago
      [deleted]
    - majkinetor 6y ago
      Tartare should be kept bellow -18 for at least 3 days as far as I know. You should never eat it fresh.
    - munificent 6y ago
      > Most fresh (killed, butchered and served quickly) food isn't really great I have eaten raw skipjack tuna that I caught myself and never froze. Tuna, as far as I know, has very little risk of parasitic infection. It was delicious.
      - Baeocystin 6y ago
        Unfortunately, tuna carries a high parasitic load, including parasites that can affect people: https://pubmed.ncbi.nlm.nih.gov/25461601/ https://pubmed.ncbi.nlm.nih.gov/25461601/ https://www.healthline.com/nutrition/raw-tuna#parasites https://www.healthline.com/nutrition/raw-tuna#parasites You got lucky, and yes, it is delicious, but you're definitely playing health roulette.
        munificent 6y ago
        Yeah, it's not necessarily something I'd do again knowing what I know today. Thank you for the links. :)
        pvaldes 6y ago
        Is not the worst fish in this sense. Cod is worse. The real problem with tuna is that is an accumulator of nasty substances like mercury and also fast and nomadic by nature. This means that you can find Japanese tuna in California, or the Mediterranean, and this can be a problem. Most of the fish parasites just turn into food after being cooked. Our stomach acid will not care. The number of marine fish parasites able to harm humans is very small. We are too hot for them. I could count all the major types with my fingers (I was surprised to learn (here) that Kudoa is a new problem in any case).
  - umvi 6y ago
    Yes, if you had sushi in a restaurant in the USA, the fish was frozen and re-thawed beforehand. https://cooking.stackexchange.com/questions/76455/in-the-usa-does-fish-being-served-raw-need-to-be-frozen-first https://cooking.stackexchange.com/questions/76455/in-the-usa...
- pvaldes 6y ago
  This is for roundworms. Is a different problem.
verylittlemeat 6y ago
Unless I'm missing a joke or something I just googled it and it says freezing only makes bacteria inactive. https://ask.usda.gov/s/article/Does-freezing-food-kill-bacteria https://ask.usda.gov/s/article/Does-freezing-food-kill-bacte...
- pvaldes 6y ago
  Freezing is lowering the temperature below zero Celsius. In anything made of water, the procedure creates ice crystals that poke the cell membrane, making a lot of microscopic holes than quickly leach the inner contents of the organism by differences in osmotic pressure. This kills the cell by "bleeding to death". As bacterias are cells with membranes in principle they are killed when frozen, so far, so good... ... but this is just the general case. Not all bacterias have being created equal and there are thousands of species. Some are extremophiles and store sugar or other substances that act as an antifreeze, so can decrease the temperature of freezing and remain "liquid" under zero point. They can stand much lower temperatures before being killed (by freezing). Is just that they are killed at -25C instead -5C, but the killer is still a tiny ice dagger. And some bacteria have evolved an outer protective gelatinous capsule, made partially with "sugar", that is not easy to pierce, so they can alter their osmotic pressure and stand more osmotic stress. And finally, some will just die, but not before creating a inner spore devoid of water that can stand the cold or dry until rehydrated. No water, no ice.
  - verylittlemeat 6y ago
    Wow I definitely wasn't expecting such a detailed explanation. Thanks :)
    - wayneftw 6y ago
      Maybe next time somebody googles it they will find this explanation.
      - laksdjfkasljdf 6y ago
        Chance is close to zero as google weight by links. and nobody links to comments.