Hollandaise sauce is used on eggs Benedict, asparagus and other vegetable dishes. Unlike other sauces, hollandaise is an emulsion. This means that the ingredients aren't blended; instead, clarified butter is suspended in egg yolks that are lightly cooked. This sauce doesn't store well, so it is usually prepared fresh, but short-term storage is possible if you prepare it ahead of the other dishes you are serving.
Place the hollandaise sauce in a heatproof bowl. Cover the bowl with a layer of plastic wrap.
Set the container on a warming plate, but do not place it directly on a stove burner, or the sauce overcooks or separates. Arrange the plastic wrap so it doesn't touch any hot surfaces. Store the container on the warming plate for up to one hour before serving.
Pour the leftover sauce into a plastic- or glass-storage bowl. Seal the lid tightly and place the bowl in the refrigerator. Store the sauce refrigerated for one to two days.
Transfer the hollandaise sauce to an uncovered, microwave-safe bowl to reheat. Microwave it at 20-percent power for 15 seconds, then stir. Continue to microwave the sauce in 15-second intervals, stirring between each, until the sauce is warmed through.