Swiss Meringue Buttercream Recipe | BraveTart
Fill a wide pot with at least 1 1/2 inches of water, with a thick ring of crumpled tinfoil placed on the bottom to act as a "booster seat" that will prevent the bowl from touching the bottom of the pot. Place over high heat until steaming-hot, then adjust temperature to maintain a gentle simmer. Combine egg whites, sugar, salt, cream of tartar, and vanilla seeds in the bowl of a stand mixer. Set over steaming water, stirring and scraping constantly with a flexible spatula, until egg whites hold steady at 185 degrees F . This should take only 10 to 12 minutes, so if mixture seems to be moving slowly, simply turn up the heat. Once ready, transfer to a stand mixer fitted with a whisk attachment and whip at high speed about 10 minutes, until meringue is glossy, stiff, and cool to the touch, around 90 degrees F .