Gazpacho Foam

For everyone who has been following Father of Food's health situation it looks like with exercise and therapy his swallowing is improving, and he is able to taste food again in the form of thickened liquids and purées, but he's keeping the feeding tube for now, because we know that his condition may worsen again.

Meanwhile, I've been thinking about what he might be able to eat that could offer the taste and aroma and textures of food without ending up in the lungs, and it occurs to me that the answer may not be in bland hospital foods, but at the cutting edge of the culinary arts, in the field of "molecular gastronomy," experimentation with science and food--food that does not even attempt to satisfy hunger, but food for food's sake. The "thickened liquids" that Father of Food has been drinking, after all, are thickened with many of the same hydrocolloids that avantgarde chefs like Ferran Adrià, Grant Achatz, and Wylie Dufresne have been playing with. Perhaps some restaurant critics think that Adrià's espumas and foams that became popular in the mid-1990s are a bit passé, but what could be more ideal for Father of Food than something intensely flavored and without any substantial mass? Of course we'll have to confirm that with his doctors and the speech therapists who work with him on his swallowing, but it seems promising, and it's always fun to learn to make something new.

Foams are typically made from liquids thickened with starch, fat, egg whites, or hydrocolloids like gelatin, agar agar, xanthan, carageenan, and other food stabilizers that may be familiar from processed food labels, but are generally naturally derived from plants or algae. They may be whipped with a blender or in a nitrous oxide cream whipper. A cream whipper like those made by iSi can whip cream to five times its original volume, or around twice the volume of cream whipped with a whisk or an electric mixer. The one that I use is the iSi Thermo Whip, which is also a thermos flask that can keep ingredients hot for three hours or cold for up to eight hours. The contents are protected by the nitrous oxide gas, so they taste and look fresh when dispensed.

While this all seems new and exotic, it is not that hard to make a foam. My first foam was simply mashed potatoes, served hot and whipped lighter than any mashed potatoes I'd ever had. It was perfect as a side dish where I might want the flavor and texture of potatoes without getting filled up on potatoes. It also worked cold as a garnish for a cold cucumber soup.

To make the gazpacho foam pictured above, blend at high speed about 1/3 cup chopped onion and one clove garlic with about 1/3 cup beef consommé and the juice of one lemon. Add about 2/3 cup tomato and an equal amount of peeled cucumber and blend thoroughly. Add marjoram, black pepper, sea salt, and piment d’Espelette or other hot pepper or Tabasco to taste. Dissolve 2g Knox gelatin in about 1/4 cup warm beef consommé, and blend into mixture. Strain and chill.

Pour one pint of the mixture into the 1 pint Thermo Whip, charge with one N2O charger, and shake vigorously, then turn the Thermo Whip upside down and shake a couple of times to bring most of the liquid to the spout. Release the foam gently at first to produce a controlled spray. If dispensed at this point, it will be drinkable. For a firmer foam that can be eaten with a spoon, allow Thermo Whip to rest in the refrigerator overnight on its side. Shake vigorously and dispense into a cocktail glass garnished with a cucumber slice and a spear of red bell pepper.