Like most microwaves we tested, the Toshiba wasn’t great at defrosting meat. This model doesn’t beep to remind you to flip the meat halfway through heating, so if you forget, the results are pretty unappetizing. The ground beef we attempted to defrost in this Toshiba remained partially frozen in the center, while the edges were slightly cooked. For that reason, we don’t ever recommend using a microwave for defrosting meat unless you absolutely have to. It’s always best to thaw meat in the fridge or under cold running water. That said, we still think the defrost mode is great for quickly thawing frozen bread or bagels.

In 1945, the heating effect of a high-power microwave beam was accidentally discovered by Percy Spencer, an American self-taught engineer from Howland, Maine. Employed by Raytheon at the time, he noticed that microwaves from an active radar set he was working on started to melt a chocolate bar he had in his pocket. The first food deliberately cooked with Spencer's microwave was popcorn, and the second was an egg, which exploded in the face of one of the experimenters.[10][11] To verify his finding, Spencer created a high density electromagnetic field by feeding microwave power from a magnetron into a metal box from which it had no way to escape. When food was placed in the box with the microwave energy, the temperature of the food rose rapidly. On 8 October 1945, Raytheon filed a United States patent application for Spencer's microwave cooking process, and an oven that heated food using microwave energy from a magnetron was soon placed in a Boston restaurant for testing.[12]
The development of the cavity magnetron made possible the production of electromagnetic waves of a small enough wavelength (microwaves). American engineer Percy Spencer is generally credited with inventing the modern microwave oven after World War II from radar technology developed during the war. Named the "Radarange", it was first sold in 1946. Raytheon later licensed its patents for a home-use microwave oven that was first introduced by Tappan in 1955, but these units were still too large and expensive for general home use. Sharp Corporation introduced the first microwave oven with a turntable between 1964 and 1966. The countertop microwave oven was first introduced in 1967 by the Amana Corporation. After Sharp introduced low-cost microwave ovens affordable for residential use in the late 1970s, their use spread into commercial and residential kitchens around the world. In addition to their use in cooking food, microwave ovens are used for heating in many industrial processes.
From the late 1970s, Japanese companies such as Sharp Corporation manufactured low-cost microwave ovens that were affordable for residential use, leading to the rapid expansion of the microwave oven market in the 1980s. After Japanese dominance for much of the 1980s, with Sharp as market leader, South Korean manufacturers began entering the market in the late 1980s, with Samsung becoming a major microwave manufacturer.[18]
The included turntable is easy to remove for cleaning, and the large programming screen allows you to specify power levels, cooking times, and menu options for shortcuts and more complex cooking tasks. If you aren’t a fan of all those automatic options, then there are an amazing 14 auto-cook options for menu buttons that can cook a specific kind of food. Even the start button stands out and is easy to use.
In 2000, some manufacturers began offering high power quartz halogen bulbs to their convection microwave models,[37] marketing them under names such as "Speedcook", "Advantium", "Lightwave" and "Optimawave" to emphasize their ability to cook food rapidly and with good browning. The bulbs heat the food's surface with infrared (IR) radiation, browning surfaces as in a conventional oven. The food browns while also being heated by the microwave radiation and heated through conduction through contact with heated air. The IR energy which is delivered to the outer surface of food by the lamps is sufficient to initiate browning caramelization in foods primarily made up of carbohydrates and Maillard reactions in foods primarily made up of protein. These reactions in food produce a texture and taste similar to that typically expected of conventional oven cooking rather than the bland boiled and steamed taste that microwave-only cooking tends to create.

Our microwave oven tests found big differences in overall performance among models. To test heating we warm up mashed potatoes, and we use frozen ground beef to test defrosting. We also test speed of heating, noise, and ease of use. We measure usable capacity, too. (Manufacturers often include space you can't use.) Plus we test how well the over-the-range models vent.
What is a microwave ovens role in your home? Do you need the best compact microwave to fit on a tiny counter and travel with you when you switch apartments? Do you need the best built in microwave that works with your oven range? No matter your kitchen appliance situation, if you’re stuck with a clunky, ugly microwave, it’s time to improve your cooking situation.
The lower temperature of cooking (the boiling point of water) is a significant safety benefit compared to baking in the oven or frying, because it eliminates the formation of tars and char, which are carcinogenic.[49] Microwave radiation also penetrates deeper than direct heat, so that the food is heated by its own internal water content. In contrast, direct heat can burn the surface while the inside is still cold. Pre-heating the food in a microwave oven before putting it into the grill or pan reduces the time needed to heat up the food and reduces the formation of carcinogenic char. Unlike frying and baking, microwaving does not produce acrylamide in potatoes,[50] however unlike deep-frying, it is of only limited effectiveness in reducing glycoalkaloid (i.e., solanine) levels.[51] Acrylamide has been found in other microwaved products like popcorn.
The most important way to ensure that your microwave lasts is to avoid slamming the door. That’s because microwaves have a dual kill switch in the latch to make it impossible for the microwave to turn on if the door is open or even compromised. That’s a good thing—but it means that the latch is a vulnerable point of potential failure. Do yourself a favor and be gentle with it.
Thanks to its compact form, retro appearance, and efficient functionality, the Daewoo Retro Microwave is our top pick for heating up food in a dorm room. Available in three colors—turquoise, red, and white—the microwave features a digital control pad that lets you choose your function and set power levels, while a retro-inspired turn knob is used to set cook time. Its 10-inch turntable is large enough for most single servings, and its 700-watt power should be sufficient for heating up leftover pizza and ramen. It also powers down in between uses, saving you money on your energy bill. There's no timer or clock display, however. A few customers noted issues with button functionality over time, but most people find this microwave more than suitable for everyday needs.
Some current plastic containers and food wraps are specifically designed to resist radiation from microwaves. Products may use the term "microwave safe", may carry a microwave symbol (three lines of waves, one above the other) or simply provide instructions for proper microwave use. Any of these is an indication that a product is suitable for microwaving when used in accordance with the directions provided.[71]

Reviewers can’t contain their delight about this microwave’s Genius Sensor, which automatically adjusts the time and power based on the food type. “It feels very futuristic to press the Sensor Heat and let the microwave figure out on its own how long it should cook for. Most of the time, it’s dead-on, too, which is nice,” praises one commenter. “It’s pretty much impossible to overcook something,” writes another. Others note they “have had nothing boil over” and it “cooks super evenly. The days of half-molten-half-frozen food are gone.” Its modern exterior is another strong selling point. “The stainless steel looks very sleek and nice and will fit in with most kitchens,” one says.


The Toshiba EM131A5C-BS is best for anyone seeking out a slightly bigger, more powerful 1,100-watt microwave. It looks similar to our main pick, the Toshiba EM925A5A-BS, but offers a few more express controls for specific tasks like cooking bacon, defrosting frozen muffins, and making oatmeal. It also has a Soften/Melt button for butter, chocolate, cheese, and marshmallows. However, we found these additional controls less intuitive to operate than what our other pick offers, and we don’t think they’ll get used often. This Toshiba also boasts a cooking sensor that’s supposed to automatically determine when your pizza or potato is hot enough, but it didn’t perform any better than the 0.9-cubic-foot Toshiba, which lacks this feature. The 1.2-cubic-foot Toshiba has a larger 12-inch turntable, so it will fit most dinner plates and a 9-inch square casserole dish. Like our main pick, this model is available in a stainless steel or black stainless steel exterior.
Spinach retains nearly all its folate when cooked in a microwave; in comparison, it loses about 77% when boiled, leaching out nutrients. Bacon cooked by microwave has significantly lower levels of carcinogenic nitrosamines than conventionally cooked bacon.[44] Steamed vegetables tend to maintain more nutrients when microwaved than when cooked on a stovetop.[44] Microwave blanching is 3–4 times more effective than boiled water blanching in the retaining of the water-soluble vitamins folic acid, thiamin and riboflavin, with the exception of ascorbic acid, of which 28.8% is lost (vs. 16% with boiled water blanching).[47]
Different microwaves are designed for different locations. A countertop microwave sits on top of your kitchen counter. An under-cabinet microwave is mounted beneath your drawers-cabinet-organizers/4044_623679_1032619_1075864'>kitchen cabinets, keeping your counter space clear. An over-the-range microwave is mounted over a range or stove. Microwaves of this type often have built-in exhaust fans and lights.
We looked for small microwaves around 0.5 cubic foot and midrange models between 0.9 and 1.6 cubic foot. Unless you really need a turntable big enough to spin a 13-by-9-inch casserole dish or two small plates, we found that models over 1.6 cubic foot had too big a footprint for most spaces. Most people use microwaves for reheating leftovers, so there’s no reason to have an oven cavity that’s large enough to fit a 20-pound turkey. That said, you’ll want to measure the diameter of your dinner plates before getting a microwave to be sure they’ll fit.
There are two types of microwave vent systems: recirculating and external. Recirculating vents simply pull the air up into the appliance, run it through a filter to remove impurities, then push it back out into your kitchen. This type of ventilation system is ductless and easier to install, but it doesn’t perform as efficiently as external ventilation. 

Direct microwave exposure is not generally possible, as microwaves emitted by the source in a microwave oven are confined in the oven by the material out of which the oven is constructed. Furthermore, ovens are equipped with redundant safety interlocks, which remove power from the magnetron if the door is opened. This safety mechanism is required by United States federal regulations.[60] Tests have shown confinement of the microwaves in commercially available ovens to be so nearly universal as to make routine testing unnecessary.[61] According to the United States Food and Drug Administration's Center for Devices and Radiological Health, a U.S. Federal Standard limits the amount of microwaves that can leak from an oven throughout its lifetime to 5 milliwatts of microwave radiation per square centimeter at approximately 5 cm (2 in) from the surface of the oven.[62] This is far below the exposure level currently considered to be harmful to human health.[63]
This invention relates to heating systems for dielectric materials and the object of the invention is to heat such materials uniformly and substantially simultaneously throughout their mass. ... It has been proposed therefore to heat such materials simultaneously throughout their mass by means of the dielectric loss produced in them when they are subjected to a high voltage, high frequency field.
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