‘Espuma’ is Spanish and means ‘foam’. So what we did here is a potato foam using a siphon and nitrous oxide. This technique was delevoped by Ferran Adrià in his restaurant el Bulli – the cradle of the molecular cuisine. The basis for the foam is a simple but very finel potato puree. We played around with it a bit and used it to top a mushroom soup.
300 grams floury potatoes
siphon with 2 nitous oxide capsels
peel potatoes and boil them until soft, strain off the water
add a little milk and knob of butter to the pot and make mashed potatoes
add more milk and butter and use puree stick to get a very fine puree
the puree has to be very smooth (small pieces of potato might get stuck in the siphon)
add more milk to turn the puree into a smooth potato-sauce, season with salt
fill the ‘sauce’ in the siphon according to the instructions and add the nitous oxide
use siphon to ‘spray’ espuma onto plate/bowl/soup….