How to thicken sauces

Flour Рthis can be used in three ways to make a roux, a beurre mani̩ or simply mixed with water or milk.

• Roux – this is made by melting the butter and mixing in the flour then cooking over a medium heat for 5 minutes. The “classic” recipes tend to call for equal quantities of fat to flour but many prefer more fat than flour which not only gives a richer flavour but also allows the roux to be combined with the liquid far easier. I prefer a lighter sauce and on average use 37 grams of butter to 30 grams of flour per half litre of liquid.
• Beurre manié – basically as above but normally used to add to sauces already made that may need extra thickening. This is a French term ie Beurre – butter, manié – handled – so named as it is normally made by mixing the flour and cold butter together to form a paste.
• Water/milk – flour and liquid combined – water is mainly used to thicken gravies for roast meats, milk to for a quick and easy way to thicken milk based sauces, ie for a simple cheese sauce where you do not have sufficient time to make it using the traditional classic white sauce.

Cornflour – mixed with water or other liquid, this may be used for thickening most sauces, but normally reserved for reduction sauces ie sauces where the liquid (stock, wine etc) is simmered until reduced. Once the liquid is ready and has boiled, removed from heat then add the mixture slowly, while whisking quickly; it will thicken almost instantly so take care not to add too much.

Arrowroot – this is used in the same way as cornflour with the added advantage that it will add a nice “sheen” to the sauce and will not dilute the sauce’s colour. Arrowroot does tend to “clarify” liquid into which it is introduced. This is especially good for fruit sauces but may not be so effective for a sauce of gravy that is meat-based. Many also think It gives the sauce an artificial appearance.

It is extremely difficult to thin down sauces thickened with either arrowroot or cornflour, so it is wise to take care.

In addition to the above, many who do not like sauces thickened with flour resort to using dried potato flakes. When the sauce is nearly read, potato flakes are sprinkled onto the cooking liquid and whisked or stirred in. The sauce must not be left on the heat after it has begun to thicken as apparently it ceases to work and the sauce will become thin again.