Kitchen Myths

Facts and fiction about food and cooking, by Peter Aitken

Kitchen Myths – What’s this Blog all About?

Many widely accepted “truths” about food and cooking are just plain false—in other words, they are kitchen myths. Learn the straight skinny here! See the About page for more information about me, your friendly myth-buster, and this blog.

Remember, these are myths–the title of each entry is the myth I am busting and is not true!

Select from the Categories list at the right or use the Search box at the top of the page to find something specific.

Aside from the color, cremini mushrooms are no different from the white ones

Your taste buds will give the lie to this myth. The brown cremini have a deeper and more mushroomy flavor than the white mushrooms. Choose based on the needs of your recipe.

On a related note, did you know that portobello mushrooms are nothing more than large creminis?

You cannot do serious cooking in a microwave

This is one of the very silliest myths but it refuses to die out. There are a lot of people who use their microwave for nothing but boiling water and reheating leftovers and they are really missing out on a lot. I suspect that this myth got its start when microwaves were a new tool and a lot of awful microwave recipe books were published. Some people tried to use their microwave as a general purpose stove and oven replacement rather than as a more specialized tool that is well suited for some jobs but not at all useful for others. For example, you would not want to use a microwave for a roast beef, fried potatoes, or baking bread, but it works just great for things like rice, poached fish, and steamed veggies. I find it particularly handy for making polenta and risotto, with results that are every bit as good as the stovetop with much less work and worry. If you want to expand your microwave repertoire I highly recommend The Microwave Gourmet by Barbara Kafka. Another excellent book is The Moghul Microwave by Julie Sahni (Indian dishes).

Hot pan, cold oil to prevent sticking

This mantra is repeated by many people as the best way to prevent food from sticking to the pan when sautéing or stir frying. The idea is that you heat up the pan first then add the cold oil and almost immediately add the food. This works of course, so it is not a myth in that it is untrue. It is, however, false to think that this is the only or the best way to prevent sticking. What you really want is “hot pan, hot oil” and that’s what you are actually getting because the cold oil heats up almost instantly when added to the hot pan. You’ll get the same results if you heat the oil along with the pan rather than adding the oil at the last minute. In fact some cooks prefer this technique because the appearance of the oil in the pan can give you some indication of when the pan has reached the proper temperature.

There is one situation where you don’t want to heat the oil in the pan, and that’s when you need a super-hot pan for searing a steak or similar tasks. It has nothing to do with sticking, however, but with the oil burning. Your pan is likely to reach 600 degrees and that is well above the smoke point of any cooking oil, so your oil will start to smoke and decompose well before the pan is ready. My approach is to not add oil to the pan at all, but rub it on the steak – patted dry first, of course – just before putting the steak in the pan.

You can’t make a good cup of tea in the microwave

Some people claim that you cannot make really good tea by boiling your cup of water in the microwave and then putting in the tea bag. The problem is that only the top layer of water is boiling – water in the lower part of the cup is not hot enough yet and so the tea will not infuse properly. Perhaps—but the problem is easily solved by letting the water boil for 5-10 seconds before removing it from the microwave and adding the tea bag. This ensures complete mixing and heating of the water and your tea will be just fine.

Note, however, that some tea experts claim that you do not want to use actively boiling water (212o) because it damages the flavor of the tea. I was informed of this by a reader named Erik Lynn – for black tea you want 195 degrees, for green tea 175 degrees, and for herbal tea 205-210 degrees. To be honest, I really can’t tell the difference, but apparently some people can.

However, be aware of a potential safety issue. Water can get superheated in the microwave. In other words, its temperature goes above the boiling point but it does not actually boil. This is usually the result of using a container with a very smooth surface that lacks the minute rough spots that trigger boiling. When you then pop your tea bag into the water it boils all at once and can leap out and burn you. Of course if you wait for the water to boil in the MW, as I have advised, this will not be a problem, but you should be aware of it.

Never put bananas in the refrigerator – they’ll become inedible

The skins will darken, but refrigeration slows ripening of bananas the same as it does other fruits. The insides will be fine.

Foods such as chicken salad made with mayonnaise are prone to quick spoilage

Another old wives’ tale (or old husband’s if you prefer). Mayonnaise, because of its relatively low pH (in other words, it is acidic) will actually help prevent spoilage. The pH (level of acidity) of commercial mayo in the US is required to be 4.5 or below, and that is very uninviting to spoilage bacteria. When chicken salad or something similar spoils, it is the other ingredients spoiling, not the mayo. When going on a picnic or setting out a buffet it is important to keep foods cold, but there’s no reason to avoid mayo.

The avoidance of mayo in some situations likely got its start back in the days when mayo was almost always homemade, and homemade mayo typically is a lot less acidic than today’s commercial product.

Don’t salt meat before cooking

The idea behind this one is that the salt will draw out juices from the meat, removing flavor and preventing the surface from browning properly. In theory salt can draw out moisture, but in the real world it does not seem to make any difference. I have salted meat before cooking innumerable times, including steaks for pan frying or grilling, roasts, and briskets headed for the smoker. I have never once seen any juice being drawn out by the salt. In addition, there are innumerable cooks ranging from at-home amateurs to professional chefs and cookbook authors—including the super-fussy people at Cooks Illustrated—who direct that salt be put on meat before cooking. It’s impossible to believe that if the myth were true, all these people would be blind to the supposedly dire effects.

If you use enough salt and let it sit long enough you will draw out moisture. But the real question is: does this reduce the quality of the final product? Not in my experience. Of course you must pat off the accumulated moisture with a paper towel before cooking if you want the meat to brown properly. In fact, drawing off some moisture may well concentrate the flavors and lead to a better result.

Myths about dried beans

There are three “facts” you’ll often hear about cooking dried beans, such as kidney and great northern beans. It turns out they are all myths.

  1. You must soak beans before cooking. You can soak beans of course, but the only advantage it provides is to shorten the cooking time. There’s no reason not to start cooking dry beans directly as long as you have the time to simmer them long enough.
  2. You must not add salt to beans during cooking or they will not soften. Tests show that the only difference between beans cooked side by side with and without salt is that one is salty and the other is not. Some people feel that salting during cooking gives better flavor because some of the salt ends up inside the beans.
  3. You must not add acid, such as tomatoes, to beans during cooking or they will not soften. Acid does in fact have an effect on beans, tending to keep the skins intact, while alkaline substances (baking soda) help the skins to break down. In both cases however the beans cook perfectly well. You can use this to your advantage, adding tomatoes during or after cooking depending on whether you want whole beans or mushy beans.

Note, however, soaking can help reduce the “gas attack” effect that some people experience after eating beans. Bring dry beans and water to a boil, remove from heat, and let sit for an hour. Drain, add fresh water, and continue cooking. This removes some of the chemicals in the beans that cause the gas.

Cold water boils faster than warm water

This is another myth that falls into the “suspend the laws of physics” category. That hasn’t happened yet in my kitchen, and if it has in yours then you can probably get on TV. Seriously, to illustrate how ridiculous this idea is without getting into physics and formulas, think of it this way. If you put cold water on to boil, at some time before it boils the water will have become warm. Let’s say it takes time “A” for the water to go from cold to warm. Then after some additional time it will boil – call the time it takes to go from warm to boiling “B”. So, the time it takes the cold water to boil is “A + B” and the time it takes the warm water to boil is “B.” If this myth were true then time “A + B” would be less than time “B” and there’s just no way this could be no matter how many martinis you’ve had. Read more of this post

If you put the pit in the bowl, guacamole won’t turn brown

The surface of guacamole turns brown by reacting with oxygen in the air. The guacamole that is directly under the pit won’t turn brown because the pit prevents air from getting to it. Otherwise, the oxidation process turns the exposed surface brown, just as it does on apples and other fruits. You’ll have much better luck protecting the surface from air by pressing aluminum foil or plastic wrap on it.

Microwave cooking is radiation and makes foods poisonous

Yes, microwaves are radiation, just like the light from the sun, the warmth from a cozy fire, or the signal that brings you radio shows. But, it is nonionizing radiation, which means that it has no effect on food other than heating it up. It has nothing whatsoever to do with the truly dangerous ionizing radiation that is associated with atomic bombs and nuclear power plants.

Microwave cooking destroys nutrients more than other cooking methods

It’s true that cooking reduces the level of some nutrients, but this is true of all cooking methods. It’s the heat that does it, and with boiling or poaching there’s also the fact that some nutrients are leached out into the water. Microwaves pose no special risk to nutrients and in fact may preserve more of them because cooking times and temperatures may be lower than with conventional cooking methods. Yes, I know that there are many web sites claiming that microwaves destroy nutrients, but they are wrong. Ask these people about their scientific background, may I suggest.

You cannot do serious cooking in a microwave

This is one of the very silliest myths but it refuses to die out. There are a lot of people who use their microwave for nothing but boiling water and reheating leftovers and they are really missing out on a lot. I suspect that this myth got its start when microwaves were a new tool and a lot of awful microwave recipe books were published. Some people tried to use their microwave as a general purpose stove and oven replacement rather than as a more specialized tool that is well suited for some jobs but not at all useful for others. For example, you would not want to use a microwave for a roast beef, fried potatoes, or baking bread, but it works just great for things like rice, poached fish, and steamed veggies. I find it particularly handy for making polenta and risotto, with results that are every bit as good as the stovetop with much less work and worry. If you want to expand your microwave repertoire I highly recommend The Microwave Gourmet by Barbara Kafka. Another excellent book is The Moghul Microwave by Julie Sahni (Indian dishes).

You can make a baked potato in the microwave

The microwave oven certainly has many legitimate uses, but baking potatoes (or anything else) is not one of them. Sure, you can cook a whole potato in the microwave, but what you get is a steamed potato. The crispy skin and fluffy interior of the genuine baked potato require a long cooking in dry heat.

You must scald milk before using it in certain recipes

This myth has some basis in fact. Raw milk (milk that has not been pasteurized) contains enzymes that can interfere with the thickening action of milk and the rising of bread. The scalding destroys these enzymes. Today, almost all the milk that is sold has been pasteurized, a process of heating the milk to destroy bacteria. This has the same effect as scalding the milk, so by the time you buy the milk those nasty enzymes are already gone. Unless you milk your own cow, you can skip the scalding.

Scalding can however be beneficial if you are making yogurt or other cultured milk products. Even pasteurized milk contains some bacteria, and they can compete with the yogurt culture and affect the result. By heating milk to 180 degrees you eliminate most of these other organisms and give the desirable culture bacterial a clean slate to work with.

You cannot deep-fry in olive oil

Olive oil has a lower smoke point than most other oils and as a result many people think you cannot use it for deep frying. Balderdash! This would be news to many Italians including the famous TV chef Mario Batali. Olive oil’s smoke point is about 375 degrees and most frying is done below that. Also, just because an oil smokes a little does not mean it is ruined.

Using olive oil for deep frying is undoubtedly expensive. The least expensive olive oil is, in my experience, about twice the cost of other oils that are used for frying such as peanut or canola. Plus you should discard the oil after a single use because the low smoke point means that the oil degrades more during that first use. So, you may never actually want to use olive oil for deep frying, but it is most certainly possible – and can give terrific results for some recipes!

You must use a serrated knife to slice ripe tomatoes

You certainly can use a serrated knife for ripe tomatoes, but there’s no need to. If you find yourself always turning to a serrated knife for this task it is probably because your straight-edged knives are not sharp enough. A well-sharpened regular knife will make paper-thin slices from a ripe tomato—in fact, some people use this as a test for a knife’s sharpness.

Gas cooktops are better than electric

It’s become almost an article of faith that gas cooktops are better than electric, and that any “serious” cook should aspire to owning one. This belief does not stand up to intelligent scrutiny, however. Gas cooktops are fine, of course, but when comparing them to electric you will see that there’s no overall objective superiority. Let’s take a look at some of the ways gas and electric differ–and then a brief look at induction cooking: Read more of this post

Avoid aluminum cookware because of Alzheimer’s disease

This myth got its start a number of years ago when medical researchers found elevated levels of aluminum in diseased tissue from the brains of Alzheimer’s patients (dead ones, I hope). One logical possibility (but not the only one) was that the raised aluminum level was responsible for causing the disease. Get exposed to too much aluminum, from your job perhaps or your cookware, and you would have a better chance of coming down with this awful disease. People started avoiding aluminum cookware, and some still are – unnecessarily it turns out. Subsequent research has failed to show any connection between aluminum exposure and Alzheimer’s, and it is believed that the elevated aluminum in the brains of Alzheimer’s patients is a result of the disease process. In other words, high aluminum levels do not cause Alzheimer’s, but rather Alzheimer’s causes high aluminum levels.

Heating a pan prevents food from sticking by closing cracks in the metal

Most cooks know that you should start with a hot pan to prevent or minimize food sticking. You may hear a bizarre theory that goes something like this: food sticks to pans because it seeps into minute cracks and pits in the pan and then solidifies when heated, becoming stuck. If you heat the pan before adding the food, the metal expands and fills in the microscopic cracks and holes in the pan’s surface or at least makes them smaller. With fewer or smaller surface defects for the food to grab onto it is less likely to stick.

Unfortunately whoever came up with this idea knew nothing about the physical properties of metals. When metal expands due to heating, each individual atom vibrates faster and faster and thus takes up more space. The result is the same as if each atom simply got a bit bigger, and the result is that the entire piece of metal, defects, holes and all, gets bigger. Thus, if you heat a donut-shaped piece of metal, the outer diameter gets bigger and so does the diameter of the hole. You have probably used this fact yourself when trying to get a metal screw lid off a glass jar. Running hot water over the lid expands the entire lid and loosens its grip on the jar, making it easier to remove. So, heating a pan would cause these hypothetical surface cracks to get larger, not smaller.

Alcohol in a recipe all evaporates during cooking so there is none in the final dish

Here’s another “common sense” myth that turns out to be false. Alcohol has a lower boiling point than water so it should all evaporate first, right? Nope – that’s not the way it works. The alcohol will evaporate faster than the water but there will still be some left after even extended cooking. The text below shows just how much alcohol is left after different methods and periods of cooking.

  • Alcohol added to boiling liquid & removed from heat: 85%
  • Alcohol flamed: 75%
  • No heat, stored overnight: 70%
  • Baked 15 minutes, alcohol stirred into mixture: 40%
  • Baked 2.5 hours, alcohol stirred into mixture: 5%

The bottom line is that no one is ever going to get tipsy from alcohol in a cooked dish, but people who want to avoid all alcohol for religious or medical reasons need to be aware that some alcohol will remain even after long cooking.

Lobsters scream with pain when boiled

It’s commendable that people do not want to inflict pain on animals, but this one is definitely false on the first account (screaming) and probably false on the second (pain).

As for the “scream,” there’s the problem that lobsters have no throat, no vocal cords, no lungs, so how could they scream at all? The fact is that the noise is caused by air trapped in the shell. When heated it expands and forces itself out through small gaps, causing the sound – sort of like when you force air out between your tightly clenched lips to make a rude sound.

Read more of this post

Sushi means raw fish

Many people think that “sushi” is synonymous with raw fish. Not so – the term actually refers to the vinegared rice. This is made by dissolving sugar and maybe a touch of salt in rice vinegar and tossing with the hot, just-cooked rice. Sushi therefore refers to vinegared rice served with other ingredients which may or may not include fish (which in turn may be raw or cooked). The vinegared rice itself is referred to as shari. Raw fish served by itself without the rice is called sashimi.

Use water instead of milk when making scrambled eggs

Some people will tell you that using milk when making scrambled eggs and omelets results in tough eggs – that you should use water instead. It’s puzzling how this myth continues to propagate because it is so easy to disprove for yourself. But if you require the pronouncement of some authority, tests by Cook’s Illustrated (the “America’s Test Kitchen” people) revealed that scrambled eggs made with water are less flavorful, do not fluff as well, and are not as soft as those made with milk. Cream is better still, but that’s another story!

By the way, this advice is for eggs cooked to be moist and creamy, the way they should be. I know some people prefer the dry, fluffy style but all we can do is feel sorry for them.

All thickening agents are created equal

A common technique in cooking is to use a starch to thicken a liquid such as a gravy or sauce. Wheat starch (flour) and corn starch are perhaps the most common, but potato starch, arrowroot, and tapioca are also used. Does it matter which one you use? Most definitely. These agents differ in five ways.

  1. Flavor: does the thickening agent add its own flavor to the sauce or is it neutral in taste?
  2. Thickening power: just how thick can you go?
  3. Consistency: the molecular structure of some starches results in long strands that can give the sauce a stringy texture.
  4. Stability: will the sauce remain thick with long cooking or will it thin out?
  5. Appearance: is the resulting sauce clear or opaque?

 Now let’s look at how the various thickening agents stack up:

Read more of this post

You can’t wash cast iron cookware with soap

This myth seems to make sense—after all, you use fat to season cast iron and soap removes fat, case closed, right? It’s not that simple.

The seasoning layer on the surface of the pan is formed when the pan is heated while in contact with some fat or oil. This may happen during normal cooking or during a special seasoning process that many people use with a new pan. The result is a chemical reaction in which that fat polymerizes, meaning that multiple individual fat molecules join together to form larger molecules. It is these larger polymer molecules that bind to the metal of the pan and form the seasoning. And, guess what, the polymer is not dissolved by soap. So, it’s perfectly OK to use a mild soap on your cast iron if you are so inclined. Never use harsh detergent, put the pan in the dishwasher, or scrub with an abrasive, however, as these will take off the coating.

Read more of this post

A box of baking soda in the fridge or freezer absorbs odors

This is a very clever and successful marketing ploy by the baking soda people, but the fact is that baking soda is very poor at absorbing odors. It seems to make sense, however, so lots of people have spent untold billions of dollars to put boxes of baking soda in their fridge or freezer to no effect. Activated charcoal would work much better but is expensive. Better to wrap your food and clean the fridge once in a while.

“Real” chili cannot contain beans or tomatoes

You hear this on a regular basis, mostly from Texans. The fact is that many delicious traditional (and non-traditional) chilis are made with beans and/or tomatoes. There is in fact some basis for this myth. Traditional Texas-style chili is usually made without beans or tomatoes, and it can be great, but that’s just one regional variant.

What about “Cincinnati” chili? I used to think it was meant as a variant on southwestern chili, and a very poor one at that. I learned  later that Cincinnati chili is actually a dish invented by Greek immigrants in Cincinnati and meant as a spaghetti sauce or hot dog topping. It has some chili powder in it, but also more traditional Mediterranean spices such as cinnamon, nutmeg, cloves, and cinnamon. Learn more on Google.

Remove the seeds from hot peppers to reduce the heat

False, but true in a way. The heat in hot peppers comes from a chemical called capsaicin, and most of the capsaicin is contained in the pith, the white material that holds the seeds in place. The seeds actually contain very little. So, you could remove just the seeds from a pepper and affect the heat not at all, but because most people remove the pith along with the seeds, they get the desired result. Although, hot peppers are supposed to be hot, so why would you do this? Another mystery!

Adding salt to the cooking water keeps greens green

Nope. You may want the salt for the taste, but it has no effect on the color of the final product. A pinch of baking soda could actually improve color by making the water more alkaline, but because most people have water that is already a wee bit alkaline to begin with, you may not notice a difference.

You must/must not salt pasta cooking water

Now wait just a minute, how can one statement and its opposite both be false? This is because there are so many divergent opinions about salting pasta water, often strongly held, and none of them is “true” in an absolute sense. Salting does not shorten the cooking time by raising the temperature of the water (it does, actually, but by a tiny amount that makes absolutely no difference). The fact is that salting does one thing and one thing only: it makes the pasta salty (well, duh!). You have to add a good bit of salt to get any real taste effect because most of the salt goes down the drain. There you have it. You want salty pasta, add salt – otherwise, no.

But, there is one situation where I think adding salt is a good idea. For the common tomato-based sauces, the sauce can add the needed degree of saltiness to the dish. With oil-based sauces, however, we face the fact that salt does not dissolve in oil, so the sauce cannot add the needed salt (and the result is often the addition of too much grated cheese to get the desired salt level). Salting the pasta water in these situations can provide a better balance. The same is true of pasta that is destined for a cold mayonnaise-based salad.

Add oil to pasta cooking water to keep the pasta from sticking

In theory, this will work–oil is slippery, after all! In realty, almost all the oil goes down the drain when you drain the pasta and the septic tank beasties will enjoy your good olive oil. Tossing the pasta with a little oil just after draining works much better. But, most sticking problems can be avoided by buying high quality pasta (which sticks less than the cheap stuff), by not overcooking the pasta, and by making sure you are boiling it in enough water. Also, stirring the pasta for 10-20 seconds right after adding it to the boiling water makes stickiness less of a problem.

Searing meat seals in the juices

This old saw has been around for ages, partly because meat cooked over low heat will exude liquid while meat cooked over high heat—seared—appears not to. When you cook meat, the collagen fibers contract and this squeezes liquid out of the meat regardless of the cooking temperature. With high heat, the liquid boils away immediately and you never see it, while at lower temperatures the liquid accumulates in the pan.

Searing, or more specifically browning, is important because of the Maillard reaction. When the proteins and sugars in meat are exposed to high heat (searing) a large number of chemical reactions take place, resulting in the creation of lots of new flavor elements. It is these flavors, both in the browned surface of the meat and in any pan juices that result, that make searing such an important step in some recipes.

Another reason for this myth may be because searing meat that will be stewed, roasted, etc. does indeed give much better results. It has nothing to do with sealing in the juices, however. Careful experiments were performed in which identical pieces of meat were cooked with and without searing. If searing did seal in juices, then the seared meat would lose a smaller percentage of its weight during cooking than the unseared piece and thus be heavier after cooking. In actuality, both the seared and unseared meat lost about the same amount of weight.

A worm in an ear of corn means you can’t eat it

The corn, not the worm! The corn earworm, Helioverpa zea, is the larva, or caterpillar, of a moth. There is almost always one per ear, and they inhabit the tip of the ear, feeding on the kernels. I have seen a lot of people at the local farmers’ market rejecting ears of otherwise excellent corn because there’s a worm. What a waste! Organic corn often has a worm, because spraying with toxic insecticides is the only way to prevent them. All you need to do is cut off the tip of the ear, removing the worm and the damaged kernels, and you’ll be fine. I’d much rather eat an ear of corn that had a worm removed than one soaked with insecticides.

You should not store coffee in the freezer

Oh pish-tush! For medium to long-term storage (more than a couple of weeks) this in fact the best place to store coffee. Coffee goes stale mainly because the oils in the coffee (I am talking roasted coffee, whole beans or ground) react with oxygen in the air and go rancid, giving the coffee a stale taste. One way to prevent this is to seal the coffee away from air—this is why coffee in cans and some bags is vacuum packed. The second way is with cold, which slows down chemical reactions. Cold, freezer, duh!

The reason I have heard for not storing coffee in the freezer is that it can absorb odors from the other food. Well, I dunno about you, but I wrap things tightly before they go in the freezer. Even if my leftover garlic and limburger tart comes unsealed, the coffee will be in a jar or zip-loc bag.

There is one situation when freezer storage may not be a good idea, and that when the weather is very humid and your kitchen is not air conditioned. Because moisture condenses on cold surfaces, there’s the risk of the coffee becoming moist when you take it out of the freezer to use. This would likely affect the coffee.

When sautéing in olive oil, use extra virgin oil for the best flavor

We all know that extra virgin olive oil has the best flavor. But, it turns out that these flavors pretty much all vanish when the oil is heated to sautéing temperatures. If you still want to use olive oil, for the health benefits perhaps, save your money and use a cheaper refined oil, saving the extra virgin for salads, dipping bread, and other non-heated uses. If you want that lovely olive oil flavor on cooked foods, drizzle a bit of the good stuff on after cooking.

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