Zabaglione Technique

The standard method for making zabaglione is to mix equal volumes of sugar and yolks, add the wine—usually Marsala, and anywhere from the same to four times the volume of yolks—set the bowl above a pan of simmering water, and whip for several minutes until the mix becomes foamy and thick. During the mixing and initial foaming, the elaborately nested spheres of yolk proteins are unpacked for action. Dilution, the wine’s acidity and alcohol, and air bubbles all disrupt the yolk granules and lipoprotein complexes into their component molecules so that those molecules can coat the air bubbles and stabilize them. When the temperature reaches 120°F/50°C, high enough to unfold some of the yolk proteins, the mix thickens, traps air more efficiently, and begins to expand. As the proteins continue to unfold and then bond to each other, the foam rises into fluffy mounds. The key to a maximally light zabaglione is to stop the heating just when the foam teeters on the cusp between liquid and solid. Further cooking will produce a stiffer, denser, eventually tough sponge as the proteins overcoagulate.