The simplest way to thicken a sauce or gravy is to add flour (in a roux) or a cornstarch “slurry.”
A roux is usually added at the beginning of cooking and adds a slightly rich flavor. It lends a cloudier, more opaque appearance.
A slurry is a quick and easy method of thickening. It’s added at the end of cooking, has a neutral flavor, and is a bit clearer in a liquid.
Flour
Ratio: 1.5 tsp per cup of liquid being thickened.
Roux: Equal parts flour & butter.
- Melt butter, whisk in flour, and cook until golden brown with a nutty fragrance.
- Once added, bring to a simmer for 2-3 minutes to activate the starch and cook off the “floury” taste.
Cornstarch
Ratio: 1tsp per cup of liquid being thickened.
Slurry: Equal parts corn starch & cold water.
- Whisk to combine
- Once added, bring to a simmer and cook for a minute to activate the starch.