If you find yourself making a lot of thickened sauces or soups, it might be a good idea to keep some precooked roux in the fridge or freezer. After cooking and cooling your roux, put it in a few ice cube trays. When solid, pop it out and tightly wrap each piece in cling film. You should be able to keep roux frozen for 6 months or more without it seperating – watch for off smells if you choose to keep it that long though.
“Rooks? What’s a rooks?”:
Roux is French, and pronounced ‘rue’. Now, I don’t speak French, and you might not either, but chances are you’ve probably made scalloped potatoes or something else that uses a basic white sauce before. A roux is that cooked mixture of flour and fat that helps to thicken whatever you make once the liquid is added. Generally, the ratio of fat to flour is one to one by weight, but this varies depending on how much fat is needed to coat your flour.
The fat used can be anything, chicken fat, pork fat, duck fat, vegetable oil, or butter. If you use an animal fat, you’ll be adding a huge amount of flavour to your dish, but also a ton of saturated fat. Butter adds a great neutral flavour, and some saturated fat – it should be clarified when making a roux (more on this in a later tip). Vegetable oil makes a cheaper alternative to butter, but if flavour is your main concern it should be avoided.
Making a roux:
The procedure for making a roux is simple – heat your fat, and dump in your flour all at once. Stir it until all the fat has coated the flour grains, and then “cook it out”. The roux should begin to resemble a smooth paste once all the flour is added. It should also not be seeping fat, if it is, add more flour and stir it in. Cook the roux over medium heat, but don’t allow it to boil or foam up. If it does, lower the heat. The flour will begin to change colour as it is cooked, resulting in three main colours of roux; white, blonde, and brown. A black or dark brown roux is used in Cajun cooking, but not often elsewhere.
Types of roux:
A white roux will take about 5 minutes of cooking. It is neutral in flavour and aroma, as the flour has not been toasted but cooked just long enough to lose the raw smell.
A blonde roux will take 10-20 minutes of cooking depending on how high of a heat you are using – try not to wander off too far when cooking a roux. A blonde roux will smell like fresh buttered popcorn. This type of roux has less thickening power than a white roux, but can add a great mild nutty flavour to your dish. You’ll also notice that the blonde roux is runnier than the white. Since it is off white, it will discolor a cream sauce.
A brown roux has the color and aroma of peanut butter or toasted nuts. It will likely take about 30 minutes of cooking over medium heat to make a brown roux. The brown roux is quite runny when hot, and has lost most of its thickening ability. Brown roux is useful for thickening dark colored sauces, soups, or stews.
Using a roux:
Its easiest to add a warm liquid into a hot roux. When making a soup for example, saute your aromatics [onions, celery, etc], add your roux, and when it has all been heated, begin to add warm stock or cream very slowly. Add only a few tablespoons at the beginning, mixing it in until fully incorporated. Add a bit more, and mix until its uniform. Repeat, adding a bit more each time. Roux needs to be ‘cooked out’ after the liquid is added to eliminate the remaining floury taste and texture. You won’t see the full thickening power of the roux until your sauce, soup, or whatever has come to a simmer. Let it simmer for 15 minutes or so to cook out the roux.
Adding cold liquids to a hot roux can cause the roux to lump up, and excesssively hot liquids can cause lumps if they gelatinize the starch too early – not only that, adding hot cream to a hot roux can burn the cream pretty easily.
