Because of their high butter content, some luxury high fat sauces such as hollandaise, choron, bearnaise, and Cafe de Paris are very difficult to make commercially.
Chefs make high fat sauces using the roux technique and these are stable for the short period of time from preparation to plate. But if consumption is too slow the butter will rise to the surface and become seperated from the sauce. For a manufacturer looking to create something with the shelf life required by retailers this is, of course, impractical. But there are ways to ensure sauce stability at the luxury end of the scale.
