the most common preparation is a "bain-marie" method where a reduction of vinegar is used to acidify the yolks. 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 flavourings may be added to a finished hollandaise ("sans" lemon juice).