Rescues · TO REDUCE
Far too salty.
Why it happens
Seasoned before reducing. Salt does not evaporate. Season at the end, always.
Recovering it
Over-reduced is easy: add water or stock back and taste. It will not be quite what it was, because aromatics have left with the steam, but body and seasoning are recoverable. Too salty is the harder one — dilution costs you the concentration you spent time building, so add unsalted liquid and reduce again, or add an unsalted bulk component. The potato trick does not work; a potato absorbs salted water at the same salinity and removes almost nothing. Scorched cannot be saved: pour the good liquid off the top without scraping, and never stir the burnt layer in.
The mechanism
Water evaporates and flavour compounds, sugars, salts and dissolved proteins mostly do not, so removing water raises the concentration of everything else. Body increases too: gelatin, starch and emulsified fat become proportionally denser and the liquid starts to coat rather than run. Two consequences follow that people routinely get wrong. First, evaporation happens at the surface, so the rate depends on pan width, not on volume or heat — a wide pan reduces several times faster than a tall one at the same temperature, and a lid stops the process almost entirely by returning condensate. Second, salt concentrates along with everything else, which is why a sauce seasoned to taste before reducing is usually too salty afterwards.
The full TO REDUCE lesson — how to tell, where to practise it, what it carries to.