Why reducing strengthens a sauce
When a sauce simmers, water leaves as steam while most of the dissolved flavor compounds, sugars and salt stay behind. Less water holding the same amount of flavor means a stronger, thicker sauce.
Salt at the end
Salt stays while water leaves, so early salt gets more concentrated as the sauce shrinks. Taste at the end and season then. Delicate herbs and lemon juice go in last too, since their aromas escape with the steam.
Test yourself
Questions from the interactive lesson, with the answer and the why.
You simmer a stock down to half its volume. What did you mostly lose?
Water, so the rest gets stronger. Water leaves as steam and the flavor left behind gets stronger.
True or false: Salting a sauce at the very start is best, because the salt has time to blend in.
False. Salt stays while water leaves, so early salt gets more concentrated as the sauce shrinks.
What went wrong? You salt a pan sauce at the start and reduce it to a third. It comes out harsh and salty.
The early salt got concentrated as water left. Salt stays behind while water leaves, so the sauce got stronger.
Fill the blank: Reducing works because water leaves as ___ while flavor stays behind.
Reducing works because water leaves as steam while flavor stays behind. Water turns to vapor and rises out of the pan.
Your pan sauce has reduced but looks thin and dull. What helps at the end?
Whisk in cold butter off the heat. Cold butter emulsifies into the sauce and gives body and shine.
