When more salt is not the answer

A flat sauce is usually short of acid, not short of salt. Four things move a sauce: salt, acid, fat and sweetness — and most people only reach for one.

1. Taste on a spoon, not off your finger, and taste it at the temperature it will be served. A sauce tasted boiling always seems underseasoned.
2. Try three drops of lemon or vinegar before you reach for salt. If the sauce suddenly tastes of itself, it was acid it needed.
3. Too salty: add unsalted liquid, not potato. The potato trick does not work — it absorbs salt and water in the same proportion, so the concentration stays exactly where it was.