Kitchen Myths

Facts and fiction about food and cooking, by Peter Aitken

Category Archives: Techniques

Stock and broth are different

Both the terms “stock” and “broth” refer to a flavorful, savory liquid made by simmering ingredients in water for a long time until all of the flavor is extracted, then straining and discarding the solids. Meat is usually part of the recipe, but not always. Some people will insist that the two are different. Stock is made with bones, they say, and broth is not. Broth is for drinking, they claim, and stock is for cooking. It’s true that come cookbook authors make these claims, but they are not consistent–what one famous chef says is stock is another chef’s broth. Let’s face it–who cares? Good stock/broth is essential to many kinds of cooking. Bad stock/broth should be fed to the pigs.

For the best tomato sauce, always use fresh tomatoes

This seems to make sense, right – I mean, fresh is always better than canned. Or is it? It turns out that canned tomatoes often beat out fresh for making sauce. There are several reasons for this:

  • The makers of canned tomatoes can grow multiple varieties with different taste characteristics and blend them for an ideal taste profile in their product.
  • The tomatoes are grown for canning near the processing plant, so they can be left on the vine until ideally ripe and at the peak of flavor – no need to account for transport time.
  • The tomatoes do not have to be bred to transport well or to look pretty on the shelf in the market. As long as they taste good, they can be delicate and ugly.

This is not to say you can’t make great sauce from fresh tomatoes–of course you can, but only if you have the ideal locally grown and perfectly ripe tomatoes. My point is that you should not dismissed canned tomato products just because they are processed. And, you do not have to buy the super-expensive imported and/or organic varieties. In fact, one of the US’s major brands beat all of those out in a taste test held by a notoriously fussy cooking magazine.

Here’s an interesting Mark Bittman article on this topic:

http://opinionator.blogs.nytimes.com/2013/08/17/not-all-industrial-food-is-evil/?_r=0

When steaming clams, discard any that do not open

I used to do this for years, also with mussels. Turns out it is usually a waste of perfectly good clams. An unopened clam may be bad, but in my experience they are usually fine. What I do is set the unopened ones aside and deal with them separately. In almost all cases they are very easy to open with a blunt knife and the little feller inside is just fine. When you do find a bad one, out it goes. If you find more than a very occasional bad one, you might want to buy your clams elsewhere.

As an aside, fresh clams should always be stored in the fridge in a ventilated container, never a sealed plastic bag. They are alive and use some oxygen – not much, but a sealed bag will suffocate them and then you will have a bunch of bad clams!

Sharp knives make cutting your fingers more likely

A sharp knife cuts more easily, so this make sense – right? But, it is not true. With a sharp knife, cutting is  easily done and nothing needs to be forced. And it’s the forcing that causes cuts, when you have to press down hard and the knife slips onto your finger. Ouch! With a really sharp knife, your cutting can be smooth and relaxed, with less danger of cuts. So, keep your knives sharp!

Roasting coffee at home is difficult and not worth the effort.

To the contrary! Since being turned on to coffee roasting a while back (after a visit to an organic coffee plantation in Nicaragua), I regret not having started sooner. If you want better, cheaper coffee for little effort, read on. If you like Charbucks – err, I mean Starbucks coffee, don’t bother.

  • Process: A coffee roaster can cost as little as $130. It looks sort of like a blender and works by blowing hot air up through the beans to agitate and roast them. Add the green (raw) beans, turn on, and forget – it’s that simple. You can vary the type of roast (light, medium, dark) by varying the roasting time and/or temperature. This process will generate some smoke, particularly when making a dark roast, so be forewarned.
  • Savings: Green coffee beans, easily available over the internet, cost in the $5-7 / pound range with a few exceptions for super-premium beans like Jamaica Blue Mountain. Beans lose 15-20% of their weight in roasting, so a pound of roasted beans ends up costing $7.00-$7.50 / pound. Compare that with the $12-15 that high quality roasted beans cost. Your savings will soon pay for the roaster and you’ll be saving money.
  • Variety: My favorite source of beans, Burman Coffee Traders, currently lists green beans from Costa Rica, Hawaii, India, Brazil, Colombia, Ethiopia, Guatemala, Indonesia, Jamaica, New Guinea, Tanzania … the list goes on. Decaf beans are available as well. Plus, you can experiments with your own blends.

So, if you love coffee – good coffee that is – you might want to try roasting your own.

Adding salt makes water boil faster

In fact, the opposite is true – dissolved salt raises the boiling point of water. For the amounts used in cooking, however, it is a tiny amount, a fraction of a degree, and you needn’t be concerned about it.

Slamming the oven door can ruin a soufflé

A soufflé is a delicate creation that rises due to expanding bubbles in beaten egg whites. A sudden shock such as the oven door slamming will, supposedly, cause it to collapse. While this may be a nice plot twist, tests show that it isn’t true – your soufflé will survive a slammed door just fine, as will delicate cakes.

Don’t store fresh corn on the cob in the fridge

Fresh corn on the cob is, of course, best cooked as soon as possible after picking, but that’s not always possible. How should it be stored? Many people say not to refrigerate it, but that’s a myth. Put it in the fridge – after all, the chemical reaction that causes corn to lose its sweetness is slowed down by cold, just like almost all chemical reactions. Corn can still be wonderful after a day or two in the fridge, although not as good as really fresh.

By the way, an easy and energy-efficient way to cook corn is to put the husks and trimmings in the bottom of your kettle, pile the ears on top, and add an inch of water – instant steamer! Cover and boil for 4-10 minutes depending on the corn and your preferences. By not bringing a full pot of water to the boil, you save time and energy.

Breath through your mouth to avoid crying when cutting an onion

The crying response to onion vapors has to do with your eyes, not your nose. Using a sharp knife, to reduce the tearing and bruising caused by a dull one, may help, as will refrigerating the onion ahead of time. Keeping your eyes closed will help, but you may lose a finger or two!

Adding a raw potato can reduce saltiness in a soup of sauce

A potato will absorb little or no salt, so this just does not work. Adding more unsalted liquid and other ingredients is about the only solution to this problem.

Acidic marinades make meat tender

Many people believe than an acidic marinade – one containing wine, vinegar, or citrus juice – will make meat tender. In fact, the opposite is often the case. Acid interacts with the proteins in the meat, causing the protein molecules to pack more closely together and thus squeezing liquid out of the meat. The result? Tough and dry steak, chicken, or what have you. What’s more, extended exposure to acid can cause the surface of the meat to become mushy because the proteins start to break down. The rule, then, would be to keep acidic marinade periods short, but then of course the flavor won’t get into the meat very well. My approach is to rely on non-acidic marinades.

The fact is, marinades in general don’t have nearly the effect that many people think because the flavors just cannot penetrate beyond a millimeter or two at the surface. Salt and water in a marinade can penetrate deeper, and the benefit of most marinades is the result this factor.

Tear basil, rather than cutting it, for best flavor

When a recipe calls for fresh basil, you’ll often hear chefs saying to tear it with your fingers, rather than shredding it with a knife, to get the best flavor. Sorry, but nope. The flavors in basil – like any herb – are primarily contained within the cells of the leaf. If you tear it, it tends to come apart between the cells so that less flavor is released (because it stays in the cells). If you cut the leaf, you will break open the cells (some of them, anyway), releasing more flavor. This makes the most difference when you are using the basil raw, as in a tomato salad. In cooked dishes, such as a sauce, it does not make as much of a difference because the cooking gets the flavor out of the cells.

My technique is to wash the basil, pat dry with paper towels, and remove the leaves from the stem. Stack several leaves together and roll into a cylinder, then cut crossways into thin strips.

A pinhole in a raw egg will prevent cracking while boiling

This myth is based on the reasonable idea that eggs crack, when being hard- or soft-boiled, because the air in the shell expands from the heat. The pinhole is supposed to release this pressure. Reasonable, yes, but tests show that a pinhole really does not reduce cracking. Rather, cracks occur either because the egg already has an invisible crack in the shell, which expands during cooking, or because the egg is being knocked about in the pan by too-active boiling.

When making a meringue, you must not get even a tiny speck of yolk in the egg whites or they won’t beat up properly

There’s a kernel of truth in this one. When you beat egg whites until they are stiff, you are actually creating a foam in which the egg white proteins form bubbles with the air you are beating in. Fats tend to collapse foams and an egg yolk contains a lot of fat, hence the origin of this “rule.” It may have had some validity when people made meringues by hand, but with today’s power mixers you’ll be able to make a perfectly good, stiff meringue even if a bit of yolk gets mixed in.

All ice cubes are created equal

Most of us use cubes made with tap water, using either an ice cube tray or a built-in ice maker. They tend to be cloudy and sometimes don’t last as long as we’d like. But, ice is ice, right? Not necessarily. Home-made ice freezes from the outside in. Air that is dissolved in the water, plus any minerals (worse if you have hard water) are pushed to the center, last to freeze, where the create bubbles and haze. The resulting ice cubes contain less actual ice than bubble-free ones of equal size would, and when they melt you may find a sediment of the previously-dissolved minerals at the bottom of your glass.

To avoid this, use distilled water (no dissolved minerals) and bring to a boil briefly, then cool and freeze (the boiling drives out most of the dissolved air). You’ll get clear, sediment-free cubes that last a food deal longer. Worth the effort? Maybe only for special occasions!

When baking muffins, fill empty cups with water for even baking

Suppose you have a 12-cup muffin tin and enough batter for only, say, six muffins. This myth says to fill the empty cups with water or you’ll get uneven baking and your tin might warp. It does no harm, but it’s a waste of time and has no effect whatever on the evenness of cooking. Why would it? Even with all 12 cups full of batter, most of them are not adjacent to another cup on one or two sides and things cook perfectly fine. If your tin warps, that’s a sign of low quality, and maybe you need a replacement.

There is one scenario where putting water in the empty cups makes sense—if you have already greased them. Baking an empty, greased cup makes for hard cleanup!

Eating grilled meat increases your chance of cancer

Sorry, it just ain’t so. I say “sorry” because there are some people who seem to want grilled meat to be unhealthy—beats me as to why (perhaps it’s the “if it tastes good it must be bad for you” syndrome?). Anyway, this myth got its start because grilling—like some other cooking techniques—produces heterocyclic amines (HCAs), which are “reasonably anticipated” to be carcinogens in humans. What this means is that there is no evidence that they actually are carcinogens in humans, but someone thinks that if they keep looking long and hard enough they will find some evidence. As an example, a recent prospective study in 120,000 women found no relationship between breast cancer and eating red meat or the way the meat was cooked. “But but but,” the worry-warts will say, “HCAs cause cancer in rats and mice!” Yes, but we are not rats or mice (most of us, anyway) and what’s true for them is not always true for us. There is evidence, for example, that early humans adapted a digestive system to safely eat cooked food while rodents did not.  Also, just because a high dose of something, like the high doses of HCAs that the experimental rats and mice were given, causes a health problem does not mean that the very small doses we get in our food will also cause a problem.

Don’t wash raw mushrooms because they will absorb water

Mushrooms naturally contain a lot of water, up to 90% by weight according to some sources. This makes them difficult to sauté properly because they will give off that water and end up stewing, at least until the water cooks off. But, they won’t absorb more water if you wash them. Of course, some water may adhere to the gills, but that can be shaken or dabbed off.

When grilling a burger, flip it only once for best results.

I am not sure where this one originated, but I hear it frequently. In fact, flipping the burger several times during grilling gives more even cooking and a more evenly browned surface. You won’t get those grate marks, but who cares? It’s going in a bun anyway. It is true that you shouldn’t press on the burger with your spatula during cooking—this just squeezes juice out, and we all love juicy burgers!

Is rare hamburger dangerous? It depends.

A lot of attention has been given to the dangers of eating a burger that hasn’t been thoroughly cooked. There’s good reason for this. Commercial ground beef is made in factories in huge batches, and a single burger can contain meat from dozens or hundreds of individual animals. The chance of bacterial contamination making it into the supermarket package not insignificant, and this is a risk that many people don’t want to take. In fact, some states have banned restaurants from selling burgers that are not well-cooked. Too bad, because real burger aficionados know that the best tasting burgers are cooked to medium at most.

Is there a way around this? Yep—grind your own beef. If your ground beef comes from a single chuck or sirloin roast (or a mix of the two, my favorite), there’s a vastly smaller chance of contamination. You must observe proper procedure, making sure your grinder is spotlessly clean and keeping everything cold, of course. Buy your meat from a reputable, high-turnover retailer. There’s no absolute guarantee against contamination, of course, but the risks are much, much lower this way and your can enjoy a juicy, pink-in-the-center burger again.

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.

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.

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 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.

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.

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.

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.

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. In actuality, both the seared and unseared meat lost about the same amount of weight.

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.

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