Steaming: Moist Heat Cooking
Steaming is a moist-heat cooking technique that employs hot steam to conduct the heat to the food item.
Once water is heated past the 212°F mark, it stops being water and turns into steam. Steaming has an advantage over methods such as boiling or even simmering is that there is no agitation involved, so it's gentler on delicate items like seafood. And because it doesn't require the food to be submerged, it avoids the loss of nutrients through leaching.
It also cooks relatively quickly.
Interestingly, steam's maximum temperature is also 212°F, just like water. But unlike water, steam can be forced to exceed this natural temperature limit by pressurizing it. The higher the pressure, the hotter the steam becomes. Cooking with pressurized steam requires specialized equipment, though, which is typically not available to the beginning cook.
Cooking With Steam
Steaming can be done on a stovetop, with a pot containing a small amount of liquid that is brought to a simmer. The item to be cooked is then placed in a basket suspended above the liquid and the pot covered.
The hot steam circulates through the pot and cooks the food very quickly. This technique is known as "compartment steaming." The bamboo steamers used in Asian cuisine are an example of a compartment steamer.
Vegetables, potatoes, and even rice can be cooked with steam.
Some vegetables like broccoli and cauliflower can turn soggy when simmered, so steaming is an excellent alternative cooking method.
Steaming is particularly well suited for cooking fish. With compartment steaming, the cooking liquid (usually a broth, stock or wine) and aromatic herbs are gently simmered.
The moist environment inside the compartment helps keep the fish juicy.
Seafood can also be steamed in its own juices. Mussels are frequently cooked in a large, covered pot with a very small amount of wine. As the pot heats up, the mussels cook in the steam from their own juices, which then combines with the wine and other ingredients to create a flavorful sauce.
Cooking en Papillote
Another technique for cooking with steam is known as cooking en papillote or "in paper." This method is frequently employed for cooking fish, and involves enclosing the food in a packet of parchment paper or foil. This packet is then heated, so that the item inside cooks in its own steam.