Reduction concentrates salt too

The most common way to ruin a sauce is to season it before it has finished reducing. Halve the liquid and you double the salt.

1. Season at the end, always. Anything added at the start — salt, soy, cured meat, stock that was already salted — arrives at the plate at double strength.
2. Use a wide pan. Reduction happens at the surface, so a sauté pan halves a sauce in a third of the time a saucepan takes — and less time means less overcooked flavour.
3. Measure with a wooden skewer: stand it in the pan at the start and mark the level. Guessing by eye in a pan you do not know well is how sauces get reduced to glue.