Vegetable oil olive, coconut etc.), and it is preferred by most "health-food" customers in the United States and in Europe. There are several different types of mechanical extraction. Expeller-pressing extraction is common, though the screw press, ram press, and ghani (powered mortar and pestle) are also used. Oilseed presses are commonly used in developing countries, among people for whom other extraction methods would be prohibitively expensive; the ghani is primarily used in India. The amount of oil extracted using these methods varies widely, as shown in the following table for extracting mowrah butter in India: The processing of vegetable oil in commercial
Butter lemon juice. Hollandaise and béarnaise sauces are emulsions of egg yolk and melted butter; they are in essence mayonnaises made with butter instead of oil. Hollandaise and béarnaise sauces are stabilized with the powerful emulsifiers in the egg yolks, but butter itself contains enough emulsifiers—mostly remnants of the fat globule membranes—to form a stable emulsion on its own. "Beurre blanc" (white butter) is made by whisking butter into reduced vinegar or wine, forming an emulsion with the texture of thick cream. "Beurre monté" (prepared butter) is melted but still emulsified butter; it lends its name to the practice of "mounting"