Béarnaise sauce

Béarnaise sauce is a sauce made of clarified butter, egg yolk, white wine vinegar, and herbs. It is regarded as a "child" of hollandaise sauce. The difference is only in the flavoring: béarnaise uses shallot, black pepper, and tarragon, while hollandaise uses white pepper or a pinch of cayenne.

The sauce's name derives from the province of Béarn, France. It is a traditional sauce for steak.

History
Legend has it that the sauce was accidentally invented by the chef Jean-Louis-François Collinet, the accidental inventor of puffed potatoes (pommes de terre soufflées), and served at the 1836 opening of Le Pavillon Henri IV, a restaurant at Saint-Germain-en-Laye. The restaurant was in the former residence of Henry IV of France, a gourmet himself, who was from Béarn.

Although the sauce is a French invention, it caught on in the Nordic countries in the late 20th century, where it forms a major part of local steak cuisine with steaks and fries, and is occasionally used there as topping on pizza, whether as part of the pizza or as a cold dressing put on afterwards.

Preparation
As with hollandaise, there are several methods for preparing béarnaise.

The most common method of preparation uses a bain-marie, whisking to a temperature of 150 F, where a reduction of vinegar is used to acidify the yolks.

Auguste Escoffier calls for a reduction of wine, vinegar, shallots, fresh chervil, fresh tarragon, and crushed peppercorns (later strained out), with fresh tarragon and chervil to finish instead of lemon juice. Others are similar.

Alternatively, the flavorings may be added to a finished hollandaise (without lemon juice). Joy of Cooking describes a blender preparation with the same ingredients.

Derivatives

 * Sauce Choron (also called béarnaise tomatée) uses tomato purée instead of herbs. It is named after Alexandre Étienne Choron.
 * Sauce Foyot (also called Valois) is béarnaise with meat glaze (glace de viande) added.
 * Sauce Paloise uses mint instead of tarragon.