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In our country, we get fresh milk from the milkman and it is usually boiled in a pan over a fire to pasteurize it before we consume the milk. In my office, we do not have gas connection, so I can't use that method.

Can I use the microwave as an alternate source of heat to boil the milk? Will the milk become pasteurized during the heating process in the microwave?

Jay
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Irfan
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  • Welcome Irfan to Seasoned Advice. I made several edits to your post to make your question a bit easier to understand. If you feel like I have changed the meaning of your question in anyway, feel free to edit it farther by using the edit link under the question tags. – Jay Jul 10 '12 at 08:27

2 Answers2

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The process of pasteurizing milk is to treat it with heat to kill microorganisms such as Brucella, Campylobacter, E. coli O157:H7, Listeria, Mycobacterium bovis, Salmonella, and Yersinia that may or may not be in the milk. This is a precautionary step that is taken when you are not 100% sure whether your source of milk is disease free.

Pasteurization can occur at different temperature for a different amount of time but the easiest temperature to pasteurize milk in the microwave is to bring it to 161 F for at least 15 seconds.

Pasteurizing the milk in the microwave is a bit tricky because overheating it make cause it to boil over and it also heats the milk very unevenly. In the worse case scenario it can curdle if you overheat it. You will need to buy a thermometer for this method.

  1. You first want to microwave the milk for a minute.
  2. Then you want to stir the milk and take a temperature reading from the stirred milk.
  3. Now you want to continue to put the milk in the microwave in short 15-30 second intervals(decreasing as it gets closer to 161 F) and stirring and taking the temperature reading each time.
  4. When it has finally reach 161 F, you want to heat it for 15 extra seconds in the microwave and at that point it should be pasteurized.

Another thing you can do is to just pasteurize it at home using your usual stove method and store the milk for later use. Once it has been pasteurized, as long as you refrigerate the milk, it will be good for a while. Just remember to quickly chill the milk(using a ice water bath) after you pasteurize it before you put it into the refrigerator.

Jay
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  • The answer is very help and the method is easy! – Irfan Jul 11 '12 at 05:41
  • why cooling quickly? I've seen this everywhere, but no reason is given about the necessity of this step. – Googlebot Jun 08 '13 at 20:57
  • @All the main reason is it's not a good idea to put hot food into the refrigerator because it will bring up the temperature of the refrigerator. This will put all of the food in your refrigerator in the "danger zone". It isn't a big issue if you are only making a small amount. But if you pasteurize a large amount of milk, it will keep the temperature of your refrigerator warm enough for long enough time to spoil the other food in your refrigerator. – Jay Jun 09 '13 at 01:33
  • @Jay no, I mean why not letting the milk cool down naturally, then putting it into the fridge. – Googlebot Jun 10 '13 at 10:58
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    @All Because if you are making are larger batch, in the time it takes to cool down to room temperature, it will be in the "danger zone" for more than two hours. http://en.wikipedia.org/wiki/Danger_zone_(food_safety) – Jay Jun 10 '13 at 15:13
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Pasteurisation is about using heat to kill (harmful) bacteria in raw products. The short answer is 'Yes, you can'. The question is how, or how long should you heat the milk.

A quick look at the Wikipedia provides some answers.

In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7°C (161°F) for 15–20 seconds.

...

A less conventional but US FDA-legal alternative (typically for home pasteurization) is to heat milk at 145 °F (63 °C) for 30 minutes.

So, with a digital thermometer and a clock, you should be able to heat the milk to a temperature between 63ºC and 72ºC and keep it there for some time.

I guess that, at the office, you'll be consuming your milk instantly, so it's best to apply high heat for a short time. Jay already answers the method of heating in the microwave.

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