Tag Archives: cooking

What’s wrong with microwaves?

In A Dissertation Upon Roast Pig, British writer Charles Lamb tells how mankind discovered cooking after “seventy thousand ages [of] eating meat raw”. With tongue firmly in cheek, Lamb relays how the son of a swineherd in ancient China accidentally burnt down a cottage full of pigs. After the fire dies, the boy pokes a pig and burns his fingers. He instinctively places them in his mouth and – Eureka! – bacon was discovered.

We may chuckle at this comical tale (which ends with all the villagers burning down huts filled with pigs so that they may taste the oh-so-magical bacon), but it’s true that for thousands of years humans have had to build fires whenever they wanted to cook. Nowadays, we cook using electricity. Burning fuel to generate heat, steam, and eventually electricity has been outsourced to powerplants, which send our electrical energy to us without our ever having to light a match. It’s rare to find someone who doesn’t prepare a meal without turning on an oven, stove, blender, food processer, rice cooker, slow cooker, etc.

It wasn’t until 1947 that Percy Spencer invented the first microwave oven (often shortened to “microwave”). This new, fireless method of cooking works on a principle that few people understand, and for that reason many people fear it. Many pseudoscientists (a.k.a. “scienticians”) encourage others to shun the microwave, claiming it chemically alters your food and is killing you. This is the naturalistic fallacy at its best, and some investigation quickly dismantles these myths.

Are microwaves radioactive? Arguably, yes; microwaves are radiations, but so are the radiations on television that provide reality TV. Which ones are worse is anybody’s guess. Microwaves are shorter in wavelength than radio waves, and higher in energy. Light is also comprised of electromagnetic waves, but they’re shorter than microwaves and even higher in energy. Still, you can’t cook food with light or read by microwaves.

Meet Magnetron – not just a cool superhero name.
(Source: Wikimedia Commons)

Microwaves can be generated by magnetrons, which spit them into your oven; the microwaves bounce around as long as the magnetron is operating. Some of the molecules in food – especially water molecules – are polar and line up with an electric field that reverses its direction nearly five billion times per second. The water molecules flip their orientations manically to keep up; in their agitation, they knock around other molecules, which also become fast-moving and excited. Fast molecules are hot molecules, and so the microwave-induced flipping spreads heat in your food.

(Not an entirely accurate representation of excited water molecules!)

What about microwaves “chemically altering” food? Is that true? Of course! This not-so-magical process is cooking. The essence of food is chemical, and all cooking methods cause chemical changes in foods.

And claims that microwaves destroy nutrients? Also true, but not unique to microwaves. Some vitamins (namely vitamin C) are destroyed by heat, so any cooking method will “destroy” some of the food’s vitamin C.

“But my microwave makes carrots and broccoli give off sparks!” Relax. There isn’t metal in your veggies. Some vegetables that are cut with sharp knives have sharp edges as a result. Those carbonized, sharp edges can act like lightning rods and develop concentrated electric field gradients, which generate sparks.

Your microwave isn’t the devil in disguise, I swear.

Text and illustrations by Jenny Labrie.



Hoffman, C.J., and Zabik, M.E. (1985). Effects of microwave cooking/reheating on nutrients and food systems: A review of recent studies. Journal of the American Dietetic Association, 85(8): 922-926.

Osepchuk, J.M. (1978). A review of microwave oven safety. Journal of Microwave Power, 13(1): 3-26.

Stone, M.A., and Taylor, L.T.  (2003). Feasibility of enhancing high-performance liquid chromatography using microwave radiation. Journal of Chromatographic Science, 41(4): 187-189.

Molecular Gastronomy-the next generation of food

 Figure 1. Coke Spherification

Nowadays, scientific technology is not only applied to analytical laboratories, but also used by some creative chefs. This new method of cooking is called molecular gastronomy, which was named by a French chemist Hervé This, and a Hungarian physicist, Nicholas Kurti in the 1980s. This special discipline investigates the physical and chemical changes of ingredients during cooking, and the chef aims to make the food more artistic, technical and healthier. For example, coke spherification, is a dessert made by coke. Also, Chef Fung, who designed the dish “Steak-tartare” which made by chopped watermelon with a sphere of mango juice and mints said he liked to trick people’s eyes and minds. “Customers may think they know the dish well, but they will be surprised when they taste it”.

Figure 2. Kitchen as a laboratory

The main purpose of developing molecular gastronomy is that scientists (or cooks) can use new ingredients, tools, and innovative methods to produce amazing products. In the ordinary kitchen, cooks use spices and herbs; similarly, in the laboratory, chemists also use fragrant organic chemicals such as 1-octen-3-ol. If you don’t have mushroom when you are cooking, chemists will add some benzyl trans-2-methylbutenoate instead, because it has a taste just like mushroom. Many chemicals can be used to reinforce the taste of our food, or change the texture so that they will become more attractive and artistic. Also, laboratory apparatus is useful in the culinary preparations. For example, cooks can use a reflux column to keep the flavor of ingredients. There are some other cooking techniques including capsule technique, liquid nitrogen, and low temperature cooking. Treating the kitchen as a laboratory is one of the key ideas to succeed in molecular gastronomy.

The video generally introduces the basic and common techniques used in molecular gastronomy.

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Using molecular gastronomy as a different style of cooking will increase the public’s interest in understanding science, especially chemistry, and inspire people to appreciate their food. Advanced technologies in molecular gastronomy provide more possibilities in culinary art, and people will be more satisfied with tasty and delicate food. Many top chefs around the world are taking the challenge to create fabulous dishes on a molecular level, and with their effort, more people will get to know and try the new way of cooking.


This, H. (2006). Food for tomorrow? How the scientific discipline of molecular gastronomy could change the way we eat. EMBO reports, 7(11), 1062.

This, H. (2002). Molecular Gastronomy. Angew. Chem., Int. Ed. 41(1), 83.


-By Qianhui Sun (Tianna)