The best brains are lamb's, but calf or ox brains are more readily available. However, which brains they are will depend on the country. They should be firm, plump and bright pinkish-white. They have no keeping properties so they should be used on the day of purchase after blanching in acidulated water. They are prepared by washing in running water, trimming any membranes and visible blood vessels, soaking and then washing again. They can then be either poached in court-bouillon or fried in butter and, in the West, are often served with beurre noisette.