In a hundred situations, but here are the classics. Pan sauces: after searing a steak, deglaze the pan with wine or stock, then reduce until it’s thick enough to coat a spoon. Gravy: turkey drippings + stock + a little flour, reduced to perfection—that’s Thanksgiving on a plate.
3 Ways to Reduce in Cooking - wikiHow
Sauces and glazes: balsamic vinegar reduced becomes a sweet, sticky drizzle for strawberries or Brussels sprouts. Tomato sauce? Simmer it down to concentrate that summer tomato taste. Even maple syrup can be reduced for a richer pancake topper—try it, you’ll never go back.
And don’t forget stocks and broths. An hour of reducing turns watery stock into liquid gold. Freeze it in cubes for instant flavor bombs later.
The pitfalls (because I’ve messed this up so you don’t have to)
You reduce too far, and you get a sticky, burnt mess. I once turned a cup of port wine into a black, bitter tar that smelled like asphalt. Learn from my tears: watch it like a hawk near the end. The line between “perfectly reduced” and “charcoal” is about thirty seconds.
Also, salt concentrates during reduction. So season after you’ve reduced, not before. Otherwise, you’ll get a sauce that tastes like the Dead Sea. And add acid (lemon, vinegar) at the end too—acids can become harsh if boiled for too long.
