The result is minimal grating of bubbles
against mix, and maximal bubble survival.
Despite the usual cookbook direction to
fold the whites and base together quickly, it’s
best to fold slowly. The disruptive shear force
felt by a given bubble is proportional to the
velocity at which it’s being pushed along the
base. The slower your spatula moves, the less
damage it will do to the foam.
The one exception to the folding rules is
the soufflé made with a fruit puree or juice
cooked with sugar to a thick syrup. Such a
base can be poured onto the foam as it’s
beaten — a soufflé version of the Italian
meringue — and will actually increase the
mix volume.
Preparing and Filling the Soufflé Dish Ever
since La Chapelle’s timbale of cream, soufflé
dishes have been prepared in two steps: first
the interior is buttered, and then coated with
sugar for a sweet soufflé, with breadcrumbs or