Meanwhile, in the bowl of a standing mixer, beat the room temperature egg whites (the egg whites will hold more air at room temperature) starting on low speed and slowly increase the speed to high until stiff peaks have formed. Turn the mixer to low speed and slowly add the sifted confectioners’ sugar, ½ cup at a time, until all the sugar is mixed in. Then, slowly pour in the cooled gelatin/beer mixture. Increase the speed and beat until thick and the volume has about double in size.