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How to Kasher a Microwave

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If you are trying to follow Kosher rules when it comes to preparing and eating food, you may wonder how to Kasher a microwave. The best microwaves can easily accommodate the Kosher lifestyle with a bit of forethought. Keep reading to learn more about Kashering microwave ovens.


  • If you are following a Kosher lifestyle, you will have to Kasher a microwave after it has been used to cook non-kosher food.
  • Begin by cleaning the microwave thoroughly and letting it sit idle for 24 hours or more.
  • Next, fill a cup with hot water or cold water and heat it for ten minutes, allowing it to boil and steam the interior.

Why Kasher a Microwave?

This isn’t a specific microwave like a flatbed microwave, it’s a process of cleaning a microwave. A microwave will need to undergo the Kasher process before its initial use or after it has been used to cook non-kosher food. This will keep it compliant for those following a Kosher lifestyle as part of their religious faith.

Insider Tip

It is not recommended by Rabbis to use your microwave to repeatedly cook non-kosher food.

How to Kasher a Microwave

Here are the various steps to Kasher a microwave oven. The process should be the same across all designs, if you are wondering what is a drawer microwave and if the Kashering process will be different. Feel free to repeat this process if you use the microwave to cook non-kosher ingredients. Try learning what you cannot put in a microwave, which includes foil and metal.

Tools Needed: Cup of water, various cleaning supplies

SKIP 1 Clean the Microwave

  1. The first thing you should do is to clean the microwave thoroughly, both inside and out.
  2. Use high-grade cleaning supplies as you see fit and take your time with them.
  3. Pay special attention to the glass plate turntable, as this component likely came into direct contact with the non-kosher food items.
  4. After cleaning, leave the microwave oven idle for 24 hours or more.

SKIP 2 Steam the Interior

  1. Fill a large cup with water.
  2. Feel free to fill it as high as you want, as you will be allowing it to overflow inside of the microwave anyways.
  3. Place the cup in the microwave and heat it for ten minutes, allowing steam to fill the interior of the appliance.
  4. Let the steam sit inside the microwave for a few minutes.

SKIP 3Rinse and Repeat

  1. Take some time to move the cup around the interior of the microwave.
  2. Repeat the steaming process one or two more times with the cup in a different location.
  3. Keep allowing the steam to rest in the microwave interior for a few minutes.
  4. Your microwave can now be used once again and will be Kosher compliant.


How to Kasher a sink?

If it is metal, pour boiling hot water over the entire sink. Porcelain sinks cannot be Kashered, even with hot water.

What can I do to prevent this in the future?

Keep an eye on what your microwave is being used for and refuse to heat up non-kosher food items, as even hot food can run into this issue.

Can I Kasher a conventional oven or a self-cleaning oven?

You may be able to Kasher any oven type, though the steps will differ depending on the materials and the design.

STAT: Kosher foods are those that conform to the Jewish dietary regulations of kashrut (dietary law), primarily derived from Leviticus 11 and Deuteronomy 14:1-21. (source)

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