Fish oil, herring

Herring oil is the rendered fat from herring, most familiar as a liquid or capsule supplement rather than a cooking oil, since its pronounced fish aroma makes it impractical for frying or baking the way mild vegetable oils are used. On the rare occasion it appears in a recipe, it might be brushed in a very small amount over grilled or smoked fish to intensify the fish flavor, but it is not a pantry oil for everyday cooking. Most consumers use it exactly as they would any liquid fish oil supplement, by the spoonful rather than in a skillet.

It should be stored refrigerated in a dark, well-sealed container, since fats from fish are especially prone to oxidizing and developing off flavors when exposed to warmth, light or air over time. As a pure fat it provides 902 calories per 100 g and is 100 percent fat with no protein, fiber, carbohydrate or sodium recorded, so a tablespoon (14 g) is the practical unit for portioning it, and it functions purely as a concentrated fat source rather than a food eaten in volume.