Airs are simply light-weighted foams made by using Lecithin (fatty substance present in egg yolks) which is emulsifier used to produce liquid emulsions or Airs. Simply combine liquid-based ingredient with Lecithin in a container and blend using immersion blender or fish tank bubbler. The result will be similar to the texture of bubble bath. It’s tolerant of high acidity and alcohol up to 30%.
As a great example I’ve made a cocktail called Mediterranean Margarita topped up with a sea salt foam. For the sea salt foam you need following ingredients: 100ml Water, 40ml Lime juice, 2 teaspoons of sea salt, 1.5g Lecithin.