Clarifying Butter

Now We’re Cooking With Fat

Fat is one of the four basic elements of food, due to its essential fatty acids, and has been used in cooking since ancient times. Fat carries the most calories out of any of the food molecules —essential during times of food insecurity— and humans have invented countless ways to imbue their food with more of it. Historically and presently, fat is treasured for carrying flavor, improving texture, and its hydrophobic properties in cooking. Used as food preservation, as part of an emulsion, and as a frying medium are some of the most popular uses of fat in cooking throughout different regions and times, each having an extensive history and playing a part in a changing the culinary landscape.

Fry Up Some Facts

Evidence suggests that frying was first done in ancient Egypt c. 2500 BCE and has evolved to the present day. Almost every culture around the world has a method of frying food. Specific techniques and equipment vary, but the basic process and result is the same. There are three types of frying: deep frying, sautéing, and stir-frying. These three methods use different amounts of oil, but the results are similar. The act of frying foods replaces the water moisture within the food with oil. If the oil is hot enough when the food is introduced to the oil, then the outer layer of the food is sealed by the heat of the oil, creating a crispy layer so that the moisture is retained. Frying food is considered a very quick method of cooking food but requires constant attention. While it is considered one of the oldest methods of cooking, frying also diminishes the nutritional value of foods, degrading some of the heat-sensitive nutrients.

Save Me Some for Later: Preservation using Fat

“Confit” is the process of preserving meats, and other foods, by covering them with a layer of fat so that the bacteria cannot access the oxygen that it needs to live. The term “confit” is derived from the French verb confire, “to preserve.” The product (usually a type of meat) is cooked in its own fat, then placed in a confit pot, then covered with another layer of oil or fat. This method of preservation can keep the meat edible for up to six months. By covering the food in a layer of fat and keeping it cold enough for fat to remain solid, bacteria cannot to survive. The best method for preserving food in fat in the current day is using hydrogenated vegetable fat. While fat doesn’t grow mold, if the fat isn’t rendered properly, or if there is any bits of meat or other organic material breaching the surface, mold can grow. Preservation using fat has been one of the most important ways of keeping protein rich food good for long journeys. Pork especially has been used historically in Europe and early American, packed into barrels with layers of fat to create an anaerobic environment.

Like Mixing Oil and Water: Emulsions

The process of emulsion is the dispersion of droplets into another liquid that are generally not soluble. In other words, fat droplets are suspended in a non-fat environment. Emulsion results when a hydrophilic (water loving) liquid is mixed with a hydrophobic (water-repelling) mixture. The first emulsion used by humans is milk, both their own and other mammals. By the 15th century, the process was being used to create new sauces, and expanded to include ice cream (1740), mayonnaise (1845) and margarine (1869). The most recognized forms of emulsion today are mayonnaise and hollandaise, in which the fat cells in the egg are suspended in a more acidic liquid. Mayonnaise is seen as one of the most basic cold emulsions, while hollandaise is a similar recipe that uses heat for the emulsion. There are three types of emulsions: temporary, semi-permanent and permanent. A vinaigrette is a temporary emulsion, as the oil and vinegar will eventually separate, while mayonnaise is a permanent example. Semi-permanent emulsions are relatively stable, but can split, or break, if they are outside optimal conditions.