Questions and Answers - Science of Bechamel Sauce

Questions & Answers - Science of Béchamel Sauce

Question:

My name is Dimitris Karydas and I am a student of the Agricultural University of Athens. I am trying to investigate the theological behavior of béchamel sauce when gelatinized starch is used for its making instead of flour. Is there an official recipe for Bechamel sauce? I mean with the exact quantities of the ingredients and other details. For example time of heating and at what temperature. Which is the exact role of the flour ? Is the way of mixing critical? Is it possible to make the sauce using gelatinized starch in liquid form instead of flour (powder)? Where can I find more information about this sauce from technological aspect? Your answers could be very helpful for the success of my experiments. Many thanks in advance. - Dimitris Karydas (3/22/01)

Answers:

From the book Kitchen Science by Howard Hillman

"You can thicken sauces by raising the ratio of solids to liquid, by using a thickening agent, or by employing a combination of these alternatives.

Increasing the solids can be accomplished in several ways. One procedure, which chefs call "reduction," is to boil the liquid for a period of time so that some of it evaporates. Many recipes, especially those of the classic French cuisine, advise the cook to reduce the liquid to 1/2 or less of its original volume, because reduction does more than thicken. It concentrates flavor. Moreover, it does not give the sauce a floury taste and grainy texture - shortcomings that are sometimes detected in starch-thickened sauces.

Thickening agents are many. The list includes emulsifying agents like egg protein that helps set custard, starches like wheat flour, gelatin extracted from bones and seaweed, pectin from fruits."