On Food and Cooking

copper bowl over a water bath; the mix
thickens at such a low temperature that direct
heat can quickly overcook it. In professional
kitchens, where experience is long and time is
short, zabaglione and sabayons are sometimes
cooked right over a flame. The advantage of a
copper bowl in making yolk foams is not
chemical, but physical: its excellent heat
conductivity makes it quickly responsive to
the cook’s adjustments. However, copper does
impart a distinct metallic flavor to the foam,
and some cooks prefer stainless steel for this
reason.
The ideal zabaglione or sweet sabayon is
soft and meltingly evanescent, yet stable
enough that it can be refrigerated and served
cold. Savory sabayons may be cooked short of
maximal fluffiness so that they remain easily
pourable, but the lubricating liquid in the
bubble walls will eventually drain out and
separate. Fortunately, a separated sabayon can
be rebeaten to its original consistency.