Roux - For Thickening Sauces with Flour and Oil

Steven Thomas

Constant attention pays dividends for the long slow cooking necessary for this recipe.

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Ingredients

1/2 cup vegetable oil e.g. Canola or Peanut oil
2/3 cups plain flour traditionally equal parts oil and flour by weight; but many authors vary it

Instructions

Heat the oil in a heavy frying pan over a medium high heat until hot (~180° C). It is hot enough when a bit of flour scattered on top sizzles.
Sprinkle 1/4 of the flour on top of the oil.
Stir in with a long handled wooden spoon
Mix the flour and oil into a smooth paste.
Gradually mix in the remainder of the flour in the same way.
Reduce the heat to medium
Cook the roux, stirring constantly. The mix should be on a slow boil, with tiny bubbles constantly breaking. You have to cook it for at least 5 minutes, but a longer cooking time gives a stronger colour and flavour (see the table below).

Notes

1 tablespoon of roux will thicken 1 to 1 1/2 cups of liquid.
Roux should be thick - about the texture of wet concrete or plaster of Paris. Add more oil or flour until it's right.
If roux does burn it will be bitter and unusable - throw it away and start again. Burnt roux will have black dots in it.
This recipe makes one cup - sufficient for the basis of a typical main course - but you can make larger quantities and store it; just place the Roux in a bowl, cover with cling film, with the cling film touching the surface, and place in the fridge.

Adapted from Kelly (1993) and Passmore (1992)