8.1: Oils and Vinegars

Oils

Oils are a type of fat that remains liquid at room temperature. Cooking oils are refined from various seeds, plants and vegetables. When purchasing oils, consider their use, smoke point, flavor and cost. Fats, including oils and shortenings, are manufactured for specific purposes such as deep-frying, cake baking, salad dressings and sautéing. Most food service operations purchase different ones for each of these needs. Fats break clown at different temperatures. When fats break down, their chemical structure is altered - the triglyceride molecules that make up fat are converted into individual fatty acids. These acids add undesirable flavors to the fat and can ruin the flavor of the food being cooked. The temperature at which a given fat begins to break down an d smoke is known as its smoke point. Select fats with higher smoke points for high-temperature cooking such as deep-frying and sautéing.

The flavor and cost of each oil must be considerations. For example, both corn oil and walnut oil can be used in a salad dressing. Their selection may depend on balancing cost (corn oil is less expensive) against flavor (walnut oil has a stronger, more distinctive flavor).

Terms

• smoke point the temperature at which a fat begins to break down and smoke.
• flash point the temperature at which a fat ignites and small flames appear on the surface of the fat.
• shortening (1) a white , flavorless, solid fat formulated for baking or deepfrying; (2) any fat used in baking to tenderize the product by shortening gluten strands.

When fats spoil, they go rancid. Rancidity is a chemical change cause d by exposure to air, light or heat. It results in objectionable flavors and odors. Different fats turn rancid at different rates, but all fats benefit from refrigerated storage away from moisture, light and air. (Some oils are packaged in colored glass container s because certain tints of green and yellow block the damaging light rays that can cause an oil to go rancid.) Although oils may become thick and cloudy under refrigeration, this is not a cause for concern. The oils will return to their clear, liquid states at room temperature. Stored fats should also be covered to prevent them from absorbing odors.

Vegetable oils are extracted from a variety of plants, including corn, cottonseed, peanuts, grape seeds, sesame seeds and soybeans, by pressure or chemical solvents. The oil is then refined and cleaned to remove unwanted colors, odors or flavors. Vegetable oils are virtually odorless and have a neutral flavor. Because they contain no animal products, they are cholesterol-free. If a commercial product contains only one type of oil, it is labeled "pure" (as in "pure corn oil") Products labeled "vegetable oil" are blended from several sources. Products labeled "salad oil" are highly refined blends of vegetable oil.

Canola oil is processed from rapeseeds. Its popularity is growing rapidly because it contains no cholesterol and has a high percentage of monounsaturated fat. Canola oil is useful for frying and general cooking because it has no flavor and a high smoke point.

Nut oils are extracted from a variety of nuts and are usually packaged as a "pure" product, never blended. A nut oil should have the strong flavor and aroma of the nut from which it was processed. Popular examples are walnut and hazelnut oils. These oils are used to give flavor to salad dressings, marinades and other dishes. Heat diminishes their flavor, so nut oils are not recommended for frying or baking. Nut oils tend to go rancid quickly and therefore are usually packaged in small containers.

Olive oil is the only oil that is extracted from a fruit rather than a seed, nut or grain. Olive oil is produced primarily in Spain, Italy, France, Greece and North Africa; California produces a relatively minor amount of olive oil. Like wine, olive oils vary in color and flavor according to the variety of tree, the ripeness of the olives, the type of soil, the climate and the producer’s preferences. Colors range from dark green to almost clear, depending on the ripeness of the olives at the time of pressing and the amount of subsequent refining. Color is not a good indication of flavor, however. Flavor is ultimately a matter of personal preference. A stronger-flavored oil may be desired for some foods, while a milder oil is better for others. Good olive oil should be thicker than refined vegetable oils, but not so thick that it has a fatty texture.

The label designations - extra virgin, virgin and pure refer to the acidity of the oil (a low acid content is preferable) and the extent of processing used to extract the oil. The first cold pressing of the olives results in virgin oil. (The designation "virgin" is used only when the oil is 100% unadulterated olive oil, unheated and without any chemical processing.) Virgin oil may still vary in quality depending on the level of free acidity, expressed as oleic acid. Extra virgin oil is virgin oil with not more than 1% free acidity (oleic acid); virgin oil may have up to 3%. Pure olive oil is processed from the pulp left after the first pressing using heat and chemicals. Pure oil is lighter in flavor and less expensive than virgin oil.

Flavored oils, also known as infused oils, are an interesting and increasingly popular condiment. These oils may be used as a dip for breads, a cooking medium or a flavoring accent in marinades, dressings, sauces or other dishes. Flavors include basil and other herbs, garlic, citrus and spice. Flavored oils are generally prepared with olive oil for additional flavor or canola oil, both considered more healthful than other fats.

Top-quality commercially flavored oils are prepared by extracting aromatic oils from the flavoring ingredients and then emulsifying them with a high-grade oil; any impurities are then removed by placing the oil in a centrifuge. Using the aromatic oils of the flavoring ingredients yields a more intense flavor than merely steeping the same ingredients in the oil. Flavored oils should be stored as you would any other high-quality oil.

Condiments

Strictly speaking, a condiment is any food added to a dish for flavor, including herbs, spices and vinegars. Today, however, condiments more often refer to cooked or prepared flavorings, such as prepared mustards, relishes, bottled sauces and pickles served to accompany foods. We discuss several frequently used condiments here. These staples may be used to alter or enhance the flavor of a dish during cooking, or added to a completed dish at the table.

Chutney (from the Hindi word for catnip) is a pungent relish made from fruits, spices and herbs and is frequently used in Indian cooking.

Fermented black bean sauce is a Chinese condiment and flavoring ingredient made from black soybeans that have been heavily salted, then fermented and either slightly mashed (whole bean sauce) or pureed (paste). Both versions are usually mixed with hoisin, chile sauce or minced garlic to produce a sauce that has an intense, pungent, salty flavor. Yellow bean sauces are similar, but milder and sweeter.

Fish sauce is the liquid drained from fermenting salted anchovy-like fish. It is a thin, golden to light brown liquid with a very pungent odor and salty flavor. There is no substitute for the savory richness that it acids to food and it is considered an essential flavoring and condiment throughout Southeast Asia, where it is used in and served with most every sort of dish.

Ketchup (also known as catsup or catchup) originally referred to any salty extract from fish, fruits or vegetables. Prepared tomato ketchup is really a sauce, created in America and used worldwide as a flavoring ingredient or condiment. It is bright red and thick, with a tangy, sweet-sour flavor. Ketchup can be stored either in the refrigerator or at room temperature; it should keep well for up to four months after opening. Ketchup does not turn rancid or develop mold, but it will darken and lose flavor as it ages.

Prepared mustard is a mixture of crushed mustard seeds, vinegar or wine and salt or spices. It can be flavored in many ways- with herbs, onions, peppers and even citrus zest. It can be a smooth paste or coarse and chunky, depending on how finely the seeds are ground and whether the skins are strained out. Prepared mustard gets its tangy flavor from an essential oil that forms only when the seeds are crushed and mixed with water. Prepared mustard can be used as a condiment, particularly with meat and charcuterie items, or as a flavoring ingredient in sauces, stews and marinades.

Dijon mustard takes its name from a town and the surrounding region in France that produces about half of the world's mustard. French mustard labeled as "Dijon" must by law, be produced ‘only’ in that region. Dijon and Dijon-style mustards are smooth with a rich, complex flavor.

English and Chinese mustards are made from mustard flour and cool water. They are extremely hot and powerful. American or "ballpark" mustard is mild and vinegary with a bright yellow color. Unless it contains a high percentage of oil, mustard never really spoils; its flavor just fades away.

Vinegars

Vinegar is a thin, sour liquid used for thousands of years as a preservative, cooking ingredient, condiment and cleaning solution. Vinegar is obtained through the fermentation of wine or other alcoholic liquid. Bacteria attack the alcohol in the solution, turning it into ace tic acid. No alcohol remains when the transformation is complete. The quality of vinegar depends on the quality of the wine or other liquid on which it is based. Vinegar flavors are as varied as the liquids from which they are made.

Vinegars should be clear and clean looking, never cloudy or muddy. Commercial vinegars are pasteurized, so an unopened bottle should last indefinitely in a cool, dark place. Once opened, vinegars should last about three months if tightly capped. Any sediment that develops can be strained out; if mold develops, discard the vinegar.

Wine vinegars are as old as wine itself. They may be made from white or red wine, sherry or even Champagne, and should bear the color and flavor hallmarks of the wine used. Wine vinegars are preferred in French and Mediterranean cuisines.

Malt vinegar is produced from malted barley. Its slightly sweet, mild flavor is used as a condiment, especially with fried foods.

Distilled vinegar, made from grain alcohol, is completely clear with a stronger vinegary flavor and higher acid content than other vinegars. It is preferred for pickling and preserving.

Cider vinegar is produced from unpasteurized apple juice or cider. It is pale brown in color with a mild acidity and fruity aroma. Cider vinegar is particularly popular in the United States.

Rice vinegar is a clear, slightly sweet product brewed from rice wine. Its flavor is clean and elegant, making it useful in a variety of dishes, especially those of Japanese or Asian origin.

Flavored vinegars are simply traditional vinegars in which herbs, spices, fruits or other foods are steeped to infuse their flavors. They are easily produced from commercial wine or distilled vinegars, using any herb, spice or fruit desired. Inferior flavored vinegars are made by adding the desired flavoring to lowgrade vinegar. The use of flavored vinegars is extremely popular but definitely not new. Clove, raspberry and fennel vinegars were sold on the streets of Paris during the 13th century. Making fruit-flavored vinegars was also one of the responsibilities of American homemakers during the 18th and 19th centuries.

Balsamic vinegar is newly popular in the United States, though it has been produced in Italy for more than 800 years. To produce traditional balsamic vinegar, reel or white wine made from specially cultivated grapes (white Trebbiano and red Lambrusco grapes among others), is reduced, then aged in a succession of wooden barrels made from a variety of woods-oak, cherry, locust, ash, mulberry and juniper- for at least 4, but sometimes up to 50, years. The resulting liquid is dark reddish-brown and sweet. Balsamic vinegar has a high acid level, but the sweetness covers the tart flavor, making it very mellow. True balsamic is extremely expensive because of the long aging process and the small quantities available. Most of the commercial products imported from Italy are now made by a quick carmelization and flavoring process. Balsamic is excellent as a condiment or seasoning and has a remarkable affinity for tomatoes and strawberries.