Boiling Water

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    • #13504
      Rame
      Participant

      Can I kill all the Bacteria at 60C or need (Water)Boiling point.

    • #100367
      mith
      Participant

      of course even boiling water doesn’t kill all bacteria

    • #100370
      biohazard
      Participant

      …although boiling long enough does πŸ™‚

    • #100415
      mith
      Participant

      So you’re the one causing global warming lol, in anycase, it’s prolly better to do autoclaving if you really need to kill more bacteria, rather than boiling

    • #100484
      skeptic
      Participant

      Depends on what you are trying to achieve. To achieve total sterility requires, as already said, autoclaving. This can be done in a domestic pressure cooker. 20 minutes pressure cooking and nothing is left alive.

      The problem is bacterial spores, which can survive even boiling for a time. However, if you only need a more modest kill off, such as rendering drinking water safe to drink, you do not need to achieve sterility. Brief boiling will do that, or even holding the water at 70 C plus for at least half an hour.

      This is the principle of pasteurisation. If you boil milk, you change it chemically. To make it safer to drink without destroying it, simply holding it at 70C for a time will kill most of the harmful bacteria. This process was supposed to have saved the lives of in excess of 50,000 people per year in Britain alone, before the development of antibiotics, who would otherwise have contracted deadly tuberculosis from drinking infected milk.

    • #100506
      JackBean
      Participant

      and I thought, that pasteurization is very short heating…

    • #100510
      skeptic
      Participant

      There is a range of pasteurisation methods. You can pasteurise milk by holding it at 70 C for about 20 seconds. This kills most of potentially harmful bacteria, but not all. It is, however, very useful in reducing disease.

    • #100512
      biohazard
      Participant
      quote skeptic:

      Depends on what you are trying to achieve. To achieve total sterility requires, as already said, autoclaving.

      Sorry to be a nitpicker, but if you boil water long enough, it becomes sterile. There is no need for autoclaving if your instrument/substance/whatever can withstand boiling. Even spores die after boiling long enough πŸ™‚

      This being said, autoclaving is usually much more effective and convenient, and thus it is very often the method of choice.

    • #101025
      Rm1989
      Participant

      For bacteria to actually die, the hot water would have to be at a temperature above what your skin can tolerate.

      Regards
      Rm

    • #101174
      sumita
      Participant

      Most Bacteria can be killed at 60c as most of them are Mesophiles.But some Bacteria are Thermophiles and the normal or the best temperature for their growth is 50c-60c. Thermophiles can even grow in boiling hot springs.

    • #101188
      canalon
      Participant
      quote sumita:

      Most Bacteria can be killed at 60c as most of them are Mesophiles. But some Bacteria are Thermophiles and the normal or the best temperature for their growth is 50c-60c. Thermophiles can even grow in boiling hot springs.

      Yes but few thermophiles are pathogenic. However some mesophiles can survive above 60ΒΊC, or produce spores that will survive boiling and then start growing again when the temperature becomes more appealing.
      Anyway the question was ‘all bacteria’ and the answer is clearly no

    • #101662
      beautiful
      Participant

      The water that we are drinking that should boiled.Chemical infection of water is also problem for us. Water need to boiled to kill disease organisms. It helps us to remain healthy.Now a days there are many thousands products on the market that claim to provide us with the purest water available, everything from filtration systems and distillation units to bottled water. It is good to use some trusted products which can give pure water.

    • #101675
      JackBean
      Participant

      that’s not true. E.g. the indian clothes sari are able to prevent cholera break through if used as filter

    • #101683
      skeptic
      Participant

      Jack

      While that may be true, to get complete protection via a drinking water filter, you need to screen out viruses as well. For example : norovirus is a common cause of excruciating gastro-intenstinal problems throughout the world, including the west, and it is caused by a virus that will pass through all but the best filters. Only a micro-pore filtration membrane will do it. Fortunately, these are available very readily.

      I have one for my own drinking water, since I collect rainwater. Said rainwater contains lots of bacteria, protozoans and viruses. Without a proper filter, my drinking water could not be trusted. Or else I would have to add chlorine.

    • #101690
      JackBean
      Participant

      yeah, I’m pretty sure, they are much available e.g. in Africa or India πŸ˜‰

      Interesting, that if are they throughout the world, I have always drunken only tap water and I was fine…

    • #101779
      biohazard
      Participant

      I almost always drink tap water when home or traveling, and back here I also drink rain water (for example at our summer house) that has not been boiled or filtered. But of course, the collection vessel must be clean and the water must not be let standing. I think I have had stomach disease once in the last 10 years, and that I got when I ate some poorly stored sausages πŸ˜›

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