Several readers have written in to ask if the thick meringue layer that forms the base of a pavlova can be made ahead of time. The answer as far as I’m aware is no, not really. Thin, crispy layers of meringue of the kind that go into marjolaine or vacherin can be kept for several days if need be, but in general thicker, softer layers don’t keep as well. Still I think we need an Aussie or a Kiwi to weigh in on this and give us a definitive answer. Little help anyone?
Reader Vicki wants to know if she can use stabilized whipped cream for the filling. She also wants to know what the heck whipped cream stabilization is and how it works. Vicki, the answer to your first question is yes (though some purists might complain). As far the second, I’ll need a little space to answer it. You may or may not know about how whipped cream works, a full explanation for that is here. Basically, whipping creates a layer of free fat molecules which coat air bubbles and keep them from popping.
Stabilization works by reinforcing those air bubbles. The firmness of the fat — and hence the integrity of the bubble coatings — is heavily dependent on temperature. So the longer whipped cream sits at room temperature the softer the coatings get and the more the bubbles begin to pop. The whipped cream starts to sag. Stabilization works not by adding firmness to the fat, but rather to the watery medium that surrounds the fat. Gelatin, for example, adds a firming lattice of protein to the water, keeping the fatty structure upright even as it softens. You get a similar effect with cornstarch (corn flour). Even sugar works as a stabilizer by forming a syrup with the water, creating a more viscous bubble medium with a lower surface tension.
Of all the common stabilizers, gelatin lasts the longest, though in most cases sugar is enough to keep whipped cream aloft for a good hour, provided it’s not too hot outside!