Pan sauce in five minutes

Searing leaves browned bits stuck to the pan. That's fond. Pour in about 120 ml (1/2 cup) of wine or stock, scrape the bits loose and boil until reduced by half. Off the heat, swirl in 1 to 2 tablespoons of cold butter.
Reduce first, then add butter
Boil the liquid until it coats the back of a spoon, then pull the pan off the heat and swirl in the butter. If the sauce boils after the butter goes in, the fat separates into a greasy layer on top.
Test yourself
Questions from the interactive lesson, with the answer and the why.
The steak is resting and the pan has dark brown bits stuck to it. What do you do first to start a sauce?
Pour in wine or stock and scrape the pan. The liquid dissolves the browned bits, which hold the flavor from searing.
True or false: Swirling cold butter into a hot sauce off the heat makes it glossy and slightly thicker.
True. Cold butter melts slowly into the liquid, forming a thickened mix of fat and water.
What went wrong? You keep your pan sauce at a boil after swirling in the butter. It ends up greasy and split.
Boiling after the butter split the sauce. Boiling breaks the emulsion and the fat separates, so butter goes in off the heat.
Fill the blank: Scraping browned bits off the pan into liquid is called ___ the pan.
Scraping browned bits off the pan into liquid is called deglazing the pan. The liquid loosens the fond so it dissolves into the sauce.
Why add the butter cold instead of melted?
It melts slowly, so the fat blends in gradually. Slow melting lets the fat mix into the liquid and stay emulsified.

