The meringue base is the easiest part of a pavlova to flavor, but also the most overlooked. Dry spices and small amounts of liquid flavorings work best. Our recipe calls for cream of tartar in the meringue, an acid that makes the foam more stable, but I usually use a little wine vinegar (red or white) or apple cider vinegar for a subtle fruity flavor. Use slightly more vinegar than an equivalent volume of cream of tartar, but not much—three quarters of a teaspoon instead of a half, perhaps.
Rose and orange blossom waters are also ideal, but best used sparingly (one teaspoon at most). Vanilla extract is a given. I’ve also had success adding booze like bourbon, but if you add too much, you may be facing extra mixing time. One meringue with two or three eyeballed shots of bourbon took a full 20 minutes to form, though form it did.
