The chemistry behind cooking and baking happens while following a recipe. Most of the chemical reactions that take place between ingredients happens during the initial mixing and blending together of those ingredients. The biggest difference I found between a pastry kitchen, and a restaurant kitchen is how fire is incorporated and utilised in the process of producing the finished result.
Fire in a pastry kitchen is utilised in two ways. The first, and likely the most obvious, is through baking.
Ingredients are mixed together, allowed to react to each other, shaped, and nearly finished before they are put in the oven to bake. The use of fire in this instance may or may not be direct, depending on the type of heat source being used. People traditionally think of baking as happening in an oven, however there are some instances where dough or batter is baked over direct heat. Many flat-breads are baked on a metal dome over an open fire, and pancakes, crepes, and waffles are poured into a pan or griddle over a heat source.
One of my favorite bread related memories happened on a three week canoe trip on the Buffalo River in Arkansas. We made bannock, a traditional Native American bread. We stuck the raw dough on the end of sticks, and baked it over the open flames of the bonfire. The finished result, when spread with homemade strawberry jam, was phenomenal. A raccoon even tried to get in on the action and scared the daylights out of my friend Jere.
The other type of heat generally employed in the pastry kitchen is direct heat in the form of boiling. Whether this takes the form of boiling sugar for confectionery work, boiling fruit for a puree, or boiling water for a bain marie, doesn’t really matter, since it’s the same general idea. Often boiling and baking can occur together in the same recipe, as in the case of a pie, where the filling is prepared by boiling ingredients together, and the crust is baked.
Fire in the restaurant kitchen, on the other hand, is the nearly alchemical process by which a cook takes a single ingredient and transforms it into something different.
Roasting, braising, sauteing, poaching, grilling, broiling, sous vide, frying, steaming, all have their own unique purpose in the cook’s repertoire. Where a pastry chef follows an exact recipe to bring about a desired reaction, chefs use an exact cooking technique.
Through the application of fire, a cook is able to extract and reabsorb juices. They are able to reduce a liquid and caramelize an ingredient. Using these techniques allows them to concentrate flavours and reintegrate them back into the food.
How well you are able to heat, concentrate, and reintegrate through the use of fire will determing how good you are at cooking.