If you think of the number 100, you are not likely to be reminded of the delightful taste of lightly cooked stuffed ravioli, crisp vegetables in olive oil or tender flavour-packed fish fillets. And yet, the number 100 plays a fundamental role in dishes such as these. Has anything come to mind? Exactly: the temperature of boiling water. Once it reaches 100°C, this precious liquid turns into steam – its gassy form – and becomes the preferred cooking method for a healthy diet, but this does not necessarily mean that it is less tasty: steam cooking, that is. Don’t underestimate it. Today, we shall be presenting some convincing arguments.
First of all, just consider the "magic" of steam: its maximum temperature coincides with that reached by water in its phase of transformation, in other words 100°C. This is what happens in normal conditions, that is to say, when pressure is around one Atm. If the pressure increases, so does the temperature of aqueous steam and this is the principle underlying the working of pressure cookers. So steam cooking makes use of the most ordinary steam at 100°C, so long as you have atmospheric pressure: all you need is a pan and a basket and you can get started.
The advantages of steam cooking vs boiling
Consequently, there are two advantages. The first is that, in steam cooking, the water comes into contact with the food in a gassy form, without immersing it in liquid. The water does not become “dirty” so there is no “boiling-point elevation” and the temperature remains practically constant.
The second advantage is that the aqueous steam cooks food while preserving its moisture. It is hard to imagine a more natural, healthy and flavour-friendly cooking method than steaming. Since there is no immersion, as in boiling, most of the nutrients and molecules responsible for providing food flavours remain, without being dispersed in the liquid.
Steam cooking vs frying
Like steam cooking, frying also quickly cooks food and therefore keeps the flavour and texture mostly intact. Also, for meats and other ingredients, the higher temperatures achievable by frying are more conducive to the lauded Maillard reaction, which is what gives a seared steak, for instance, its browned appearance and unique flavour. However, the oils or fats used for frying or sautéing will inevitably make foods cooked this way more calorie rich than their steamed counterparts. Also, steaming makes much less of a mess than frying, which can spatter oil on surfaces and leave you with greasy pans to clean up.
How to steam food right
Now that we’ve compared steaming to some other popular cooking methods, we can draw up some rules for steaming food properly.
First of all, make sure there is plenty of water under your basket. In this way, even if the liquids released by the food fall into the pan or into the dish, the variation in temperature will be negligible. Another important recommendation is not to salt the water: this is a common error which actually serves no purpose. The steam released is nothing but water, in any case, and if you add salt you will only delay evaporation: to add flavour, add salt to the food once it is cooked.
At this point, choose your ingredients carefully: red meat for instance does not lend itself well to steam cooking. Chicken morsels are preferable, but vegetables, potatoes, fish and rice work the best. Try cooking some simple broccoli, for instance: you will not believe the taste. When steaming fish, learn to aromatise the cooking liquid. Use one part white wine to four parts water, adding spices and herbs such as pepper grains, bay leaves and thyme.
