Place the egg whites into the bowl of a stand mixer fitted with a whisk attachment. Let sit at room temperature for 30 minutes.
90 grams large egg whites (about 3 egg whites)
Preheat the oven to 300F. Line half baking sheets with parchment paper or silicone mats.
Meanwhile, in medium size bowl, sift together the superfine sugar, cream of tartar and salt. Discard any large pieces of sugar left. Set bowl aside.
60 grams superfine, caster or granulated sugar, ¼ teaspoon cream of tartar, ⅛ teaspoon fine sea salt
In a separate large bowl, sift together the cocoa powder, confectioner's sugar and almond flour. Discard any large pieces of almond remaining. Set the bowl aside.
150 grams confectioner's sugar, 120 grams finely ground almond flour, 1 tablespoon cocoa powder
Beat the egg whites on medium speed until foamy, about 3 minutes.
Beat in the granulated sugar mixture to the foamy egg whites.
Whip the egg white mixture until stiff peaks form. The meringue will stand up straight when the whisk is removed. The egg white mixture will be thick and glossy.
Whisk in the red gel color.
¾ teaspoon red gel food color
Remove the bowl from the stand mixer. With a spatula, fold in the almond flour/confectioners' sugar. The egg whites will deflate a little bit and that is ok. The batter is ready when it "ribbons", which means it falls off the batter in a stream, like lava. You should be able to make a "8" with the batter falling off the spatula. This means the batter is ready. You're looking for about 60-75 folds. Check for the ribboning after every 15-20 seconds.
Fill a piping bag fitted with a round tip (Wilton 1A or 2A) and pipe 1 ½" rounds on the parchment paper.
Firmly tap the pans on the counter 2-3 times to remove air bubbles. Let the macarons sit until just slightly tacky, but no batter comes off on your fingers, about 30-45 minutes.
Bake the macarons for 20 minutes, one pan at a time. Cool on the sheet pan for 20 minutes.