The cook can thicken the fluid with truly
substantial particles or molecules (oil
droplets, egg proteins) to slow its drainage
from the bubble cell walls, or include
emulsifiers (egg-yolk lecithin) that stabilize
the bubble structure itself. On the other hand,
the very delicacy and evanescence of
unreinforced foams is a part of their appeal.
Such foams must be prepared at the last
minute and savored as they disappear.
Thickening a liquid with oil droplets and air
bubbles. These tiny spheres act much as solid
food particles do, interfering with the flow of
the liquid surrounding them.
Real Sauces: Multiple Thickeners The
sauces that cooks actually make are seldom