All About Steaming
Steaming is a moist heat cooking method. Although cooking occurs at a higher temperature than in braising, stewing or poaching, steaming is one of the most gentle cooking methods as food is not agitated by bubbling liquid during the process. From our junior high science classes, we all know that steam is water converted to its vapor state at the boiling point. Since the boiling point of water is 212° F (100° C) at sea level, the highest temperature at which steam can cook food is 212°F/100°C. You can increase this pressure somewhat by placing steam under pressure, but in the home kitchen, expect steaming to occur right at or around the boiling point of water.
As a cooking method, steaming was used as far back as the Paleolithic Period. Evidence has been found that the Aurignacian people of southern France, considered the first “modern” humans in Europe, cooked foods by wrapping them in wet leaves, a steaming method that is still used today (think tamales).
While steaming is not a method that is very prevalent in Western kitchens, many cultures rely heavily on steaming—China, India, and many North African countries come to mind. I started wondering: Why this stark contrast between cultures that cook with steam and those that do not? The most viable notion that I have found to explain this is that steaming requires little energy because it can be done with a relatively small amount of liquid. In countries where both fuel for fires and water are hard to come by, steaming enabled people to cook a lot of food relative to fuel and water, allowing them to make the most of their resources.
Aside from being a “frugal” cooking method, steaming is also a very healthy cooking method. First, since food is cooked by direct contact between steam (conduction) as well as the movement of the hot vapor through the food (convection), no fat is needed to conduct the heat. Often, just a squirt of lemon juice is all you need to add to a steamed dish. This makes steaming a lower-calorie, low fat cooking method. Food stays moist, too, since it is being bathed in water vapor. Also, since water soluble nutrients (namely Vitamins C and B) don’t leach out into vapor, steaming preserves up to 50% more nutrients than other moist heat cooking methods.
What to Steam
Since steaming is such a gentle cooking method, it is perfect for cooking delicate foods—most vegetables, white meat fowl, and fish are all good candidates for steaming. Other applications for steaming include Chinese dumplings, and by association other stuffed pastas such as ravioli, and even biscuit-style dumplings and other bread-type doughs.
(Have you ever dropped blobs of biscuit mix on top of stews and then put on the lid? The dumplings cook by simmering/braising on the bottoms and by steaming on the tops). Other foods that work well with the steaming cooking method are potatoes and other starchy vegetables (corn, carrots, etc), small semolina pasta (including couscous), fruit and cakes (such as Great Britain’s steamed puddings).
Although there are a lot of steamers available made of everything from bamboo to plastic, steaming really requires no pieces of specialized equipment. For larger foods, such as pieces of meat or fish, you can improvise a steamer by placing a roasting rack in the bottom of a large pot. As long as the cooking liquid you are using does not touch the food, you’ll be steaming in no time. For smaller foods, such as cut vegetables that would fall through a roasting rack, you can use an inexpensive steamer insert. You’ve seen these—the diameter adjusts to fit whatever pot you put it in. You can improvise this insert by using a metal colander set in a large pot.
Bamboo steamers are meant to be stacked on top of each other, allowing you to steam 2, 3 or even 4 different dishes at one time. This is possible because, since the flavor stays in each food instead of leaching out into liquid, flavors are not transferred between dishes.
How to Steam
Steaming is a very straightforward procedure.
- Pour some water in the bottom of your lidded cooking vessel (wok, pot, etc)
- Place food to be steamed in a steamer basket/insert/improvised steamer
- Put the insert into the pan, cover and let the water come to a boil over medium heat.
Once the water is boiling, most vegetables can be steamed in five minutes or less. Don’t steam vegetables for longer than seven or eight minutes, or they will lose their vibrant color. Meat and fish steam in 3-10 minutes, depending on the size and thickness of the food. Since steaming occurs at 212F/100C and a good poaching temperature is 140F-170F, it takes less time to steam meat than it does to poach it.
Steaming in the Microwave
Since the microwave cooks by exciting water molecules and doesn’t brown food, it is a natural for steaming. I steam vegetables in the microwave by sprinkling some water or broth onto raw, seasoned vegetables, covering them tightly with a Microwave-safe plastic wrap, cutting a couple of slits in it, and microwaving on high for 3-5 minutes. The results: perfectly steamed, crisp-tender vegetables.
Since microwaves have been shown to be good for steaming foods, many microwave steamers are available on the market.
In doing research for this article, I did find some information that indicated a degraded nutritional value in foods steamed in a microwave versus foods steamed in a traditional steamer. The FDA has deemed foods cooked by microwave safe for human consumption, so use your best judgment.
Adding Extra Flavor
Just because steaming is a healthy way to cook doesn’t mean it has to be bland. There are many ways of adding extra flavor to steamed food during the cooking process. You can bring extra flavor to your food by adding all sorts of complementary herbs and spices to your cooking liquid. Further up the flavor by substituting stock, fruit juice or wine for water. The additional flavors will permeate the food as the steam cooks them.