The original version, from Brittany, is almost always prepared with Muscadet wine, which is made from grapes grown in the area surrounding the city of Nantes on France’s Atlantic coast. Muscadet has the crisp, clean flavor and the acidic edge essential to a successful beurre blanc. If Muscadet is unavailable or too expensive, other wines can be used, but if only wines containing relatively little acidity are available, it may be necessary to add a few additional drops of vinegar to wake up the sauce at the end.

The recipe that follows contains a small amount of heavy cream, which, although not essential, will help start the emulsion. A great deal of myth still surrounds the addition of the butter to the flavor base. Many authors insist that the butter be added in tiny increments, often as little as a tablespoon (15 milliliters) at a time, over low heat, and imply that the sauce will break if the butter is added any faster. In fact, the butter can be cut into relatively large cubes (about 1 inch/2.5 cm on each side) and added all at once over high heat. The keys are to not stop whisking and not let the sauce boil. Seasonings can be added at the end. Traditionally, 1 teaspoon (5 milliliters) fine salt is added per 2 cups (500 milliliters) sauce, but diners today often find this to be slightly too much.