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How to fix a sauce that's too thin

Simmer it uncovered to reduce and thicken it, or stir in a little cornflour mixed with cold water and let it bubble for a minute or so.

How you can tell

  • The sauce runs off food instead of coating it
  • It looks watery or pools on the plate
  • It won't coat the back of a spoon

Why it happens

Sauces thicken in a few main ways. Reducing a sauce boils off water, which concentrates both the flavour and any natural thickeners already in it. Starches such as flour and cornflour absorb liquid and swell when heated, thickening the sauce. Emulsions and dairy can add body too. A sauce ends up thin when there is too much liquid, not enough thickener, or it hasn't been cooked long enough for the starch to work.

How to fix it

Option 1Reduce it

  1. Bring the sauce to a simmer with the lid off
  2. Stir now and then so it doesn't catch
  3. Stop when it coats the back of a spoon, then check the seasoning

Option 2Add a cornflour slurry

  1. Mix a spoonful of cornflour with a splash of cold water until smooth
  2. Stir it into the simmering sauce a little at a time
  3. Let it bubble for a minute or so until it thickens and turns glossy

Option 3Whisk in beurre manié

  1. Mash soft butter and plain flour together into a smooth paste
  2. Whisk small pieces into the simmering sauce
  3. Simmer for a few minutes to cook out the raw flour taste

Next time

  • Add liquid gradually and stop when the sauce looks right
  • Leave the lid off near the end of cooking so it can reduce
  • Remember that many sauces thicken a little as they cool

Terms on this page

General kitchen guidance, not food-safety advice. If food may be unsafe, for example undercooked meat or anything left out too long, follow the Food Standards Agency and throw it away if in doubt.