Thickening sauces and sauce basics

In short: Sauces are thickened with starch, a flour-fat mixture (roux), cream, egg yolk or reduction. The choice determines texture and flavour.

In more detail: On heating, starch granules swell and bind liquid. Reducing evaporates water, making the sauce more intense.

In detail

• Roux: Sweat butter and flour and deglaze with liquid. Basis for béchamel and velouté.
• Cornflour/starch: Mix with cold water (slurry) and stir into boiling liquid. Bring to the boil briefly.
• Reduction: Boil down uncovered until the consistency is right.
• Liaison: Stir in egg yolk or cream at the end, do not boil any more (otherwise it curdles).
• Avoiding lumps: Cold liquid to hot roux or vice versa, whisk vigorously.
• Seasoning: Finish with salt, acid and pepper (nudeln-richtig-kochen).