In addition to looking at the color of the liquid butter as it cooks, keep your eyes trained on the solids; the butter is ready when the bits are very dark brown.
Ingredients
4 tablespoons unsalted butter
1 teaspoon finely grated lemon zest
1 tablespoon fresh lemon juice
1 1/2 teaspoons hot sauce
1/4 teaspoon kosher salt
Directions
Cook butter in a small skillet over medium heat until it foams then browns (be careful not to let it burn), about 5 minutes.
Quickly transfer butter to a small bowl, scraping in browned solids. Let cool.
Chill brown butter 10 minutes. Stir to distribute solids. Continue to chill, stirring every 10 minutes, until butter starts to solidify.
Stir in lemon zest, lemon juice, hot sauce, and salt. Transfer to a piece of plastic; roll into a log. Freeze 1 hour before using.
