I was recently talking to some co-workers who wanted to know a little about roux. So, here’s some insight on what roux is used for and when to use it.
First, when you refer to roux, what you are talking about is flour and butter mixed smooth and cooked. Roux is used as a thickening agent for various things such as soups and sauces. It is one of the ingredients in three of the mother sauces; there are I believe seven mother sauces now, which are the main sauces that all other sauces come from.
The three that you would use a roux for are: béchamel sauce, which is a white sauce; velouté, which is a light stock made from chicken, veal or fish bones that have not been browned and thickened with roux; and an Espagnole sauce, which is a brown sauce containing tomatoes. When you look at just those three items, you might notice that the color of each of them is different. Béchamel is a white and velouté also is supposed to be light in color, but Espagnole sauce is a brown sauce. What this means is that there are a few different roux. The difference between them is decided by how much you cook them.
For the first two, you want a blonde roux, so it is cooked very little. All you want to do is cook the flour flavor out of it. You don’t want any color or flavor that will affect your sauce. For the brown sauce, however, you do want the brown color or your sauce will appear too pale. A dark roux will have a nutty smell and flavor to it, which is good for the stronger sauces. When someone mentions that he or she made a brown sauce all that means is that he or she made a brown stock and thickened it with a brown roux. Also, a brown roux will not have as much thickening power as a light roux.
As for the common uses in everyday cooking, roux is used for soups, sauces, chowder and stews. I will use roux for many sauces and gravies. To avoid the lumps in the gravy use a second bowl and thicken the gravy a little at a time. Take some of the liquid —only the liquid and no other solids — out of the main batch that is already at a low boil and place it in the bowl. Stir in a little roux until this is smooth and a little thicker and add this to the gravy. Take a little more liquid from the main batch, thicken it in the bowl and add it back into your gravy. Continue this until you get your desired thickness.
Also, when in doubt, strain it out through a fine strainer. For this reason, it is always better to thicken the liquid before adding anything like mushrooms for gravy or your chunks of potatoes and clams for chowder.
When thickening stew, use a darker roux for beef and lighter roux for chicken, but use the same side-bowl method; try to get as much liquid and as little meat and vegetables as possible while thickening it. One last thing to remember is that once you thicken something with roux, it will burn to the bottom of the pot very easily. Be sure to turn the heat way down and continue to stir it.
Equal parts flour and butter
Melt the butter and stir in the flour. Cook on the stove top, stirring to avoid browning if for light roux. Cook in the oven ,stirring occasionally for dark roux.