Foolproof Swiss Meringue

Bring 2 cups of water to a simmer in a medium pot.

Combine sugar egg whites salt and cream of tartar in the bowl of a stand mixer.

Reduce the heat of the pot and place the bowl over the steam. Whisk egg whites lightly until a digital or candy thermometer inserted into the mixture reads 160 degrees F (71 degrees C) 6 to 10 minutes. Remove from heat immediately.

Place bowl back onto the stand mixer with a whisk attachment. Whisk on high speed until egg whites are cool and stiff peaks form about 3 minutes. Mixture should hold peaks effortlessly and start balling up around the whisk attachment while appearing silky shiny and pure white.

Use meringue immediately. It will hold its shape without separating for about a week in the refrigerator.