After you sear meat, the pan holds browned bits stuck to the bottom. Cooks call them fond, and they are the start of a quick sauce.
Key idea
A pan sauce: pour off excess fat; sweat shallots; deglaze with wine, stock or juice, scraping up the fond; reduce by boiling until thicker and stronger; finish by swirling in cold butter off the heat (monter au beurre); season and serve. Reduction concentrates flavor because water boils away.
Why it works
Reducing by half means half the volume is left, so everything that doesn't boil away (salt, acid, gelatin, sugar) is twice as concentrated. That's why you season at the end.
Worked example: Reduction
You reduce 2 cups of stock by three-quarters. How much is left?
- Three-quarters is gone; one-quarter remains.
- $2 \times \tfrac14 = \tfrac12$ cup.
Answer: ½ cup.
Worked example: Salt concentrates
A stock has 1 teaspoon of salt in 4 cups. You reduce it to 1 cup. How salty is it now, per cup?
- The salt stays: 1 teaspoon in 1 cup instead of ¼ teaspoon per cup.
- Four times as salty.
Answer: Four times as salty: 1 teaspoon per cup.
Safety
- Pour wine or spirits into the pan off the heat, away from the flame, then return it to the heat.
Common mistake
Letting the fond burn black. Burnt fond is bitter; deglaze while it is brown.
Practice at home
- Sear a pork chop or chicken breast. Rest it while you make a pan sauce with shallot, ½ cup stock, a splash of vinegar or wine, and a tablespoon of cold butter.
- Measure a cup of stock, reduce it by half, and taste it next to the original.
In Meal Prep
- Delmonico Steak: a steak with a butter finish
- Hunter's Chicken: a pan sauce with mushrooms and wine