oil

Oil is a lipid substance that is liquid at room temperature, derived from plant seeds, nuts, fruits, or animal sources. Oils are composed primarily of triglycerides—fatty acids bound to glycerol—and vary widely in their fatty acid composition, which determines their flavor, smoke point, and culinary applications. Plant-based oils are extracted through pressing, crushing, or solvent extraction from sources such as olives, rapeseed (canola), sunflower seeds, sesame seeds, coconut, and peanuts, while animal-derived oils include fish oil and rendered fats from meat. The color, flavor intensity, and nutritional profile vary significantly by source and extraction method; cold-pressed or extra virgin oils retain more flavor and nutrients, while refined oils undergo processing to remove impurities and increase smoke points.

Oils serve multiple functions in cooking: as cooking mediums for sautéing, frying, and roasting at temperatures suited to their smoke points; as finishing drizzles to add flavor and richness to completed dishes; as emulsifying agents in vinaigrettes and sauces; and as a primary ingredient in marinades and dressings. Different oils are matched to specific applications based on their heat stability and flavor profiles—neutral oils like canola and sunflower are used for high-heat cooking, while robust oils like extra virgin olive oil and sesame oil are typically used unheated or at low temperatures to preserve their distinctive flavors. Oils also feature prominently in baking and pastry-making, where they contribute to texture and moisture in cakes, cookies, and breads.