Claudi Mans - The Science of Cooking: A Quick Immersion

The destiny of food is to feed, for which it must be prepared, cooked, savored, digested and absorbed by the organism. Food technologists prepare food so it can reach our mouths, and dieticians, nutritionists and doctors worry about what happens to the food inside of us, and what happens inside of us from the food. The interface between these two worlds, the exterior and the interior, is the mouth and its surrounding area. It is the chefs and experts in gastronomic sciences who take care of this part. And this is the setting for this book: how chemistry provides knowledge and technology for the preparation of nutritious, tasty and healthy food, which is why we focus on the kitchen. We will take a short excursion both outwards and inwards, but will attempt to stay in our area.

If the reader wishes to prepare some chicken croquettes for dinner, they can follow various methods: buy frozen croquettes already battered and ready to fry, buy prepared croquettes at their butchers shop or delicatessen, or take the time to prepare the croquette dough and then batter and fry them. We are going to follow this last option, the most difficult, to take advantage of leftovers. We will look for a recipe online that seems reliable and do it as best we can, improvising on what cannot be followed exactly.

We take some leftover roasted chicken along with some sauted vegetables, such as peppers or onion, and chop it all up with a knife or a meat grinder. We will grind the chicken until the chunks are the size we want for the croquette. Now we will make a bechamel sauce by taking some butter, which we will heat in a saucepan, adding in flour until the ingredients become very gooey. Then we add milk in small quantities, stirring it well so it mixes with the dough. When we have enough quantity and its texture is correct, very thick, we mix the bechamel with the chicken and chopped vegetables, along with some salt and, if we want, some grated nutmeg. We shape the croquettes into the desired size and coat them in breadcrumbs and beaten egg.

Then we need to fry them, and here there are also three basic options: we can use a frying pan with a fingers worth of hot oil, or a deep fryer with a few cups of oil. Alternatively, we can prepare them in the oven, practically without oil. If we use a deep fryer, which is the option I recommend, we set it at 330-340F and when it is ready, we immerse the croquettes in the oil until they are golden brown. We then place them on a paper towel and they are now ready to eat.

All of the above is the what , what all cooks should do to prepare a dish. But what the reader wishes to know is the why , given that they have bought a book about science in the kitchen. Throughout the process of making the croquettes we can ask ourselves, for example, why frozen croquettes are usually smaller than the ones from the butchers shop or our own. Or why we give them an oval shape and not a round one. Or what happens to the flour when we mix it with butter so that it turns dark. Or why we batter them with breadcrumbs and beaten egg, and do not just fry them directly. Or why the temperature should be 330F not 300F. Or how many times we can use the oil in the deep fryer. These many questions have different levels of depth geometric, chemical, physical, technological that require knowing the whys on different descriptive levels. These different levels and sciences involved are what make the kitchen a complex world, whose explanation and understanding require a certain order.

Responding to the whys requires knowing details of the ingredients we are using and the particularities of the processes. Specifically, and for our example, lets go to a level that delves deeper than the previous questions. We must know how the chicken is cooked, and why its skin ends up golden and crunchy and the meat not so much. Why the vegetables get soft when they are cooked. What are the particles of flour like, and what happens to the flour when it is mixed with the melted butter and, before this, what is butter. And what is bechamel, and why does it have properties between an elastic solid and a more or less gooey liquid. And, also, what reactions are responsible for the golden crust on the croquette or on the chicken skin. And how does the heat from the coat of oil manage to penetrate inside the croquette. And what are the reactions that change the composition of the oil in the deep fryer over time and the number and type of foods fried in it.

All this leads us to the need to know three basic and fundamental aspects: their composition , that is, what chemical substances the foods are made of and what gives them color, aroma and flavor; and their structure , that is to say, how are these substances arranged, forming the animal and vegetable biological structures cells, organs and organisms that are the ones we will use in the kitchen. And, then, how composition and structure is modified when the food is subjected to changes in temperature, alone or in the presence of other ingredients: the physical changes and the chemical reactions. All of this will allow us to understand, with greater or lesser depth, how each culinary technique works, and even in what direction culinary novelties are heading in the future in regard to both techniques and ingredients. As such, knowledge on what we have and judicious use of science allows us, in a certain way, to predict the future: it is the recipe for everything in life, and in the kitchen as well.