Preparation Special equipment: a long-handled spoon; a seltzer siphon (optional) Pour milk into a 16-ounce glass and place spoon in glass. Pour seltzer (or squirt if using siphon) into glass to reach 1/2 inch below rim. (A snow-white foam will develop.) Pour syrup into center of white foam, then stir in syrup and remove spoon through center of foam.