Foams
Foams (arie) are a technique developed by Ferran Adrià at elBulli in 2003. They consist of large, uniform-bubble foams obtained by emulsifying air into an aromatic liquid. The texture is evanescent: aromas spread across the palate with no perceptible weight or mass.
The preparation starts from a water-based liquid, rich in aroma and flavour. If it does not already contain a natural emulsifier, one is added: soy lecithin for liquids free of sugar and alcohol, sucro-esters in other cases. Air is incorporated with an immersion blender until a stable foam forms.
For large-scale production — events, banquets, table service for hundreds of covers — Future Cooking Lab developed the Airator, a device that produces foams in seconds at a scale far beyond what conventional tools allow.
How it works
The stability of a foam depends on the balance between the surface tension of the liquid and the ability of the emulsifier to form a film around the air bubbles. Soy lecithin lowers the surface tension of water and positions itself at the water-air interface, creating a mechanically stable layer. The size and uniformity of the bubbles determine the perceived texture: large bubbles produce very light foams, small bubbles a denser and more persistent foam.