White Sauce

I think of white sauce as more of a technique than a recipe, and I get A LOT of milage out of it.  I discovered the roux-based sauce while reading Cooking for Geeks, by Jeff Potter (I highly recommend this book to anyone interested in food science or learning to cook-- ISBN 9780596805883).  He includes a recipe from Béchamel Sauce and a couple different variations.  And that got me started.  Using this technique, you can make everything from gravy to alfredo sauce.  (One of my favorite things to do with it is beer-cheese sauce, but that'll be another day.)

 To make the Roux, melt butter in a saucepan, then add roughly the same volume of flour (usually you see 1-2 Tbsp of each-- more for more a larger recipe, obviously.)  Let the flour/butter mixture brown a bit for optimum flavor.  Be aware, though, there's a trade-off involved: Browning the flour reduces its thickening power.

After a couple minutes, start slowly adding milk or cream.  What does "slowly" mean?  Add a bit of milk/cream (or broth, even, but you want a fatty broth-- the fats interact with the flour to thicken the sauce), then stir like crazy until the texture becomes uniform. Otherwise, you wind up with lumps, and it doesn't thicken as effectively.  Not the end of the world, but not ideal.  In the photo above, the mixture is almost ready to have more milk added.  (See how there's still a bit of unincorporated milk at the edges?)

Continue gradually adding liquid until the sauce becomes liquid-y.  You can then add in bulk until you have the desired volume of sauce.  [Potter's recipe calls for only 1 cup of milk to be added to a roux made with 1 Tbsp each of butter and flour; using cream allows more liquid to be added.]  If it seems a bit thin, don't freak out.  Allow the sauce to gently simmer (stirring constantly to avoid burning) until it thickens.  This is also the time to season your sauce!  Add salt, pepper, cheese, herbs...  here's where you define and differentiate your white sauces. The sauce pictured here was flavored with Lowry's seasoning salt, fresh basil, and black pepper.  White sauce is also great when flavored with mustard (with or without cheese).