Fats and Oils

Fats are organic compounds that are made up of carbon, hydrogen, and oxygen. They are a source of energy in foods. Fats belong to a group of substances called lipids, and come in liquid or solid form. All fats are combinations of saturated and unsaturated fatty acids.

Nutrition

Fat is one of the 3 nutrients (along with protein and carbohydrates) that supply calories to the body. Fat provides 9 calories per gram, more than twice the number provided by carbohydrates or protein. Fat is essential for the proper functioning of the body. Fats provide essential fatty acids, which are not made by the body and must be obtained from food. The essential fatty acids are linoleic and linolenic acid. They are important for controlling inflammation, blood clotting, and brain development.

Culinary Functions

In addition to being a vital nutrient, fat performs a number of culinary functions.

• Provides rich flavor and silky mouthfeel.
• Carries and blends the flavors of other foods
• Carries flavor compounds and nutrients that are soluble only in fat.
• Provides visual elements that make food appear to be moist, creamy, fluffy, or shiny.
• In baking, fat performs chemical functions, such as tenderizing, leavening, aiding in moisture retention, and creating a flaky or crumbly texture.
• In cooking, fat transfers heat to foods and prevents them from sticking.
• Fat holds the heat in food, emulsifies or thickens sauces, and creates a crisp texture when used for frying.

Saturated Fats

These are the biggest dietary cause of high LDL levels (“bad cholesterol”). Saturated fats are found in animal products such as butter, cheese, whole milk, ice cream, cream, and fatty meats. They are also found in some vegetable oils — coconut, palm, and palm kernel oils. (Note: Most other vegetable oils contain unsaturated fat and are healthy.)

Unsaturated Fats

Fats that help to lower blood cholesterol if used in place of saturated fats. However, unsaturated fats have a lot of calories, so you still need to limit them. Most (but not all) liquid vegetable oils are unsaturated. (The exceptions include coconut, palm, and palm kernel oils.) There are two types of unsaturated fats:

• Monounsaturated fats: Examples include olive and canola oils.
• Polyunsaturated fats: Examples include fish, safflower, sunflower, corn, and soybean oils.

Trans Fatty Acids

These fats form when vegetable oil hardens (a process called hydrogenation) and can raise LDL levels. They can also lower HDL levels (“good cholesterol”). Trans fatty acids are found in fried foods, commercial baked goods (donuts, cookies, crackers), processed foods, and margarines.

Hydrogenated  and Partially Hydrogenated Fats

This refers to oils that have become hardened (such as hard butter and margarine). Partially hydrogenated means the oils are only partly hardened. Foods made with hydrogenated oils should be avoided because they contain high levels of trans fatty acids, which are linked to heart disease. (Look at the ingredients in the food label.)

Animal Cooking Fats

Butter–Before refrigeration, butter was typically made from soured cream.  After the advent of refrigerated storage, uncultured butter from fresh, pasteurized cream or Sweet Cream Butter became popular in North America.  Pasteurization reduces the amount of bacteria responsible for spoilage and fermentation. Butter contains at least 80% fat or butterfat, no more than 16% water and 2-4% milk solids.  Sweet cream butter is characterized by a smooth, and neutral flavor.  Sweet butter is unsalted and is preferred for cooking and baking.

Salt had been added to butter in the days before refrigeration as preservative.  Salted butter still uses salt to extend its shelf-life as well for its flavor.  Preferring to control salt directly, most cooks prefer to use unsalted butter for cooking and baking.

European or Cultured butter is made from cream in which fermentation—the conversion of milk sugars into lactic acid—has begun to take place.  Fermentation creates a sharp, “cultured” taste. Cultured butter is the preferred style in most of continental Europe.

When butter heated and allowed to settle, it separates into layers of milk solids, water and pure butterfat.  Removing  its water and milk solids the pure fat is referred to as clarified butter.  Clarified butter has a higher smoke point than regular butter and can be used in higher heat cooking.  Traditional Indian cooking uses ghee, which is made by heating unsalted butter until the milk solids sink to the bottom and brown. The foam is skimmed, and then the pure butterfat is poured off, leaving the solids behind. Ghee has a nutty flavor,  can be stored at room temperature.  

Pungent-tasting preserved butters such as smen, a Moroccan delicacy, belong to a variety known as fermented butter; they have been allowed to age for anywhere from two weeks to two years and are sometimes seasoned with herbs and spices.

Whipped butter was invented around the mid-20th century, and made by whipping nitrogen gas into churned butter.  (Air would have introduced oxygen to the butter and promoted spoilage.)  Whipped butter is  designed to be soft enough to spread when you take it out of refrigeration.  Whipped butter is not suitable for cooking.

Lard–Lard is the fat from pigs. Lard was commonly used in many cuisines as a cooking fat or shortening, or as a spread similar to butter. Its use in contemporary cuisine has diminished; however, many contemporary cooks and bakers favor it over other fats for select uses. The culinary qualities of lard vary somewhat depending on the part of the pig from which the fat was taken and how the lard was processed.

Lard can be obtained from any part of the pig as long as there is a high concentration of fatty tissue. The highest grade of lard, known as leaf lard, is obtained from the “flare” visceral fat deposit surrounding the kidneys and inside the loin. Leaf lard has little pork flavor, making it ideal for use in baked goods, where it is valued for its ability to produce flaky, moist pie crusts. The next highest grade of lard is obtained from fatback, the hard subcutaneous fat between the back skin and muscle of the pig. The lowest grade (for purposes of rendering into lard) is obtained from the soft caul fat surrounding digestive organs, such as small intestines, though caul fat is often used directly as a wrapping for roasting lean meats or in the manufacture of pâtés.

Schmaltz (Chicken and Goose Fat)–Schmaltz is rendered, (clarified) chicken or goose fat used for frying or as a spread on bread and associated with the Ashkenazi (German, Austrian and Polish) Jewish cuisine. The English term “schmaltz” is derived from Yiddish and refers to fat rendered from domestic fowl. In German the term Schmalz, also refers both tallow, lard and clarified butter. Schmaltz rendered from a chicken or goose was used by northwestern and eastern European Jews who were forbidden by kashrut (Jewish dietary laws) from frying their meats in butter or lard, the common forms of cooking fat in Europe, as butter, being derived from milk, cannot be used with meat under the Jewish prohibition on mixing meat and dairy, and lard is derived from pork, an unkosher meat. Tallow derived from beef or mutton suet (the raw material for tallow) is  also forbidden by Jewish dietary laws. Cooking oils, such as olive oil and sesame oil, commonly used in the Middle East and around the Mediterranean were not commonly available to the Northwestern and Eastern European Jews.

Suet and Tallow (Beef Fat)–Suet is raw beef or mutton fat, especially the hard fat found around the loins and kidneys. Its high smoke point makes it ideal for deep frying and pastry production. However, suet has a melting point between 113°F and 122°F. This high melting point makes suet difficult for human digestion. The primary use of suet is to make tallow, although it is also used as an ingredient in cooking, especially in traditional puddings, such as British Christmas Pudding. Tallow, the rendered form of suet, is solid at room temperature and unlike suet, tallow can be stored for extended periods without the need for refrigeration.

Tallow is for the production of (non-vegeatble) shortening. It is one of the main ingredients of Native American food called pemmican. Before switching to pure vegetable oil in 1990, the McDonald’s corporation cooked its French fries in a arguably superior tasting mixture of 93% beef tallow and 7% cottonseed oil.  Currently, McDonald’s French fries and hash browns contain beef flavoring derived from hydrolyzed wheat and milk that is added during production.

Horse Fat–In countries where horse is regularly eaten, horse fat is also used as a cooking fat.  Famously, Belgium used horse feet and beef tallow for frying Belgium fries.  Recently, perhaps to to costs or concerns over health, many restaurants in Belgium have switched to plant-based oils.

Duck Fat–Duck (and goose) fat is prized for it’s superb taste and richness. Duck and goose fat has many applications. It’s often mixed with other oils for deep frying because it has a high smoking point (and high cost), which can withstand high heat without burning. Considered by some as better than butter, duck fat can be used in sautéing for recipes on duck cassoulet and even stir-frying vegetables, making duck confit, roasting potatoes, and even adding it to savory pastries. The goose fat can be used the same way, including frying potatoes and latkes with it.

Other Fats

Margarine–Margarine is an imitation butter spread used for spreading, baking, and cooking. It was originally created as a substitute for butter from beef tallow and skimmed milk in 1869 in France by Hippolyte Mège-Mouriès.

Modern margarine is made mainly of refined vegetable oil and water. While butter is made from the butterfat of milk, modern margarine is made from plant oils and may also contain milk. In some locales it is colloquially referred to as “oleo”, short for oleomargarine. Margarine, like butter, consists of a water-in-fat emulsion, with tiny droplets of water dispersed uniformly throughout a fat phase which is in a stable crystalline form.

Margarine has a minimum fat content of 80%, the same as butter, but unlike butter, reduced-fat varieties of margarine can also be labelled as margarine (in some countries). Margarine can be used both for spreading or for baking and cooking. It is also commonly used as an ingredient in other food products, such as pastries and cookies, for its wide range of functionalities.

Shortening–Shortening is any fat, except butter, that is solid at room temperature and used to make crumbly pastry. Shortening is used in pastry doughs.

Originally, shortening was synonymous with lard and considered a “Poor man’s lard.” Since the invention of hydrogenated vegetable oil in the early 20th century, “shortening” has come almost exclusively to mean hydrogenated vegetable oil. Vegetable shortening shares many properties with lard: Both are semi-solid fats with a higher smoke point than butter and margarine. They contain less water and are thus less prone to splattering, making them safer for frying. Lard and shortening have a higher fat content compared to about 80% for butter and margarine. Vegetable shortening was much cheaper to produce than lard and also required no refrigeration.

Oils

An oil, by definition, is a fat that’s usually liquid at room temperature.  Oils used in cooking are made from vegetables, seeds, nuts, and fruit. Oils are also plant-based and as such contain no cholesterol and are often high in unsaturated fats.  There are a few oils that do contain saturated fat, such as coconut oil, palm oil and palm kernel oil, and are solid at room temperature.

Oils are sensitive to heat, light, and exposure to oxygen and can spoil or turn rancid. Oils should be store in a cool, dry place out of direct sunlight.

One important aspect of fat is its ability to be heated to relatively high temperatures without boiling or otherwise breaking down. This is what allows fried foods to brown and cook quickly. If heated to high enough temperatures, however, fat will begin to break down and an acrid flavor develops, effectively ruining anything cooked in it. The temperature at which this occurs, known as the smoke point, is different for each type of fat. Generally, vegetable oils begin to smoke around 450°F/232°C, while animal fats begin to smoke around 375°F/191°C. Any additional materials in the fat (emulsifiers, preservatives, proteins, carbohydrates) lower the smoke point. Because some breakdown occurs at moderate temperatures and food particles tend to get left in the fat, repeated use of fat also lowers the smoke point.