It's quite dangerous to hard-boil an egg in the microwave as it may simply explode and making a big mess. Cleaning the microwave after that kind of accident to avoid a bad smell can be a miracle.
Are there any safe methods of hard-boiling an egg in the microwave?
You can immerse the egg in a mug of water so that heat is transferred in more slowly; I've done it when no stove was available. It's not necessarily a time-saver, though.
BTW, whole potatoes can also explode unless pierced many times, I have found to my regret. It produces instant mashed potatoes -- all over the oven.
I found simply covering the eggs completely in a mug and adding a tablespoon of salt to the water prevented any explosions. Ran the microwave on full for ten minutes, took it out and sat it for two minutes. Transferred to a bowl of cold water for another two minutes and then shelled it. Perfect hard-boiled egg with no grey ring. :)
You can use a toothpick to place a small hole in the ends of the egg puncturing the membrane. This allows pressure to escape. It will also allow some egg to escape as it expands, but not too much. Place it in water as mentioned above. I haven't done this in a few years, but I think 1.5 to 2 minutes is the cook time.
Frameshift: You want to boil an egg easily, so your first instinct is the microwave. Instead may I recommend an even easier way, the rice cooker!
Put a half cup of water in the bottom of the cooker and place as many eggs as you want in the plastic basket that comes with it. Then press "steam" for 12-15 minutes. Your eggs are done!
I've recently discovered rice cooker cooking and it's made everything so much easier. The rice cooker maintains boiling water at the perfect temperature so you don't have to stand over the stove watching it to make sure the water doesn't boil over. Instead, you press a couple buttons and then relax. I use the steamer basket to cook all sorts of things like frozen fish (no dethawing needed) to frozen veggies, not to mention putting rice and grains in the bottom part and you have an complete meal just like that.
I think anyone who's impressed by the convenience of the microwave, should add a rice cooker to their kitchen.
I've been using the Nordic Ware Microwave Egg Boiler for a few years. Depending on the size of the eggs, you'll need between 6.5 and 8 minutes at 1100 watts. Once you've settled on a brand and size of eggs, you can get them perfect every time - hard boiled, soft yolk etc. by tweaking the cooking time between those two values.
Fantastic gadget, 4.5+ stars on Amazon with over 1200 reviews.
Using an Inverter Microwave, I bring a bowl of water to a boil first thenput in the egg(s) and then use 20% power to keep the water at a simmer. Timing depends on how many eggs and whether you want soft or hard boiled eggs. If I'm hard boiling a dozen or more eggs I use a pressure cooker.
Here are few ideas:
use a microwave safe bowl or cup with just enough water to cover the eggs and boil the water without eggs, then turn the heat off and put the eggs in for 12-15 minutes (soft or hard) using medium power,
Consider adding 1/4 teaspoon of vinegar and salt, and cover the dish.
wrap each egg in a piece of aluminium foil (make sure that whole shell is covered) and put it into water - foil prevents the microwaves from penetrating the shell causing exploding eggs and water in the foil should prevent the arcing.
Warning: Be careful, as too high temperature for too long can even blow open the door of your microwave, so proceed with caution.
Source: Boil an egg in the microwave at Cooking SE
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