A properly made hollandaise sauce is smooth, buttery, pale lemon-yellow-colored and very rich. It is lump-free and should not exhibit any signs of separation. The buttery flavor should dominate but not mask the flavors of the egg, lemon and vinegar.
Occasionally, a hollandaise will break or separate and appear thin, grainy or even lumpy. A sauce breaks when the emulsion has not formed or the emulsified butter, eggs and liquid have separated. This may happen for several reasons. The temperature of the eggs or butter may have been too high or too low; the butter may have been added too quickly; the egg yolks may have been overcooked; too much butter may have been added or the sauce may not have been whipped vigorously enough.
To rescue and re-emulsify broken hollandaise you must first determine if it is too hot or too cold. If it is too hot, allow the sauce to cool. If it is too cold, reheat the sauce over a double boiler before attempting to rescue it.
For 1 quart (1 liter) of broken sauce place 1 tablespoon of water in a clean stainless steel bowl and slowly beat in the broken sauce. If the problem seems to be that the eggs were overcooked or too much butter was added, add a yolk to the water before incorporating the broken sauce.
CLASSIC HOLLANDAISE SAUCE:
2 sticks unsalted butter
1/3 cup distilled white vinegar
1/3 cup water
1/2 tsp. white or black peppercorns, crushed
3 egg yolks
2 tsp. fresh lemon juice
Salt and cayenne pepper to taste
Melt butter in a small saucepan, over low heat. Skim off and discard the foam that rises to the top (you are making clarified butter). Remove butter from heat.
Boil vinegar, water, and peppercorns, in a small saucepan over high heat until reduced by half; strain and set aside.
Simmer 1 inch of water in a medium saucepan over medium low heat. Whisk egg yolks in a medium stainless steel bowl. Place bowl over simmering water (don’t let bowl touch the water); add vinegar reduction and whisk vigorously until the yolks thicken to the point that the whisk leaves trails in them, about 2 minutes. Remove bowl from the pan; whisk in the lemon juice. Begin whisking in the warm clarified butter a drop at a time. As it is incorporated add the butter in a thin stream. If mixture gets cold, return bowl to the pan of simmering water and continue whisking in butter. After the butter is incorporated and if the sauce seems too thick, add a little water to thin it a bit. Adjust seasonings to taste.