Home for the Hollandaise

Hollandaise has a paradox at its heart. Its two major components, water and fat (egg yolks, a major ingredient, are 50% water), have a natural aversion to each other. Consider what happens to a salad dressing made of oil and vinegar: After a few minutes in the bottle or bowl, it separates into two layers, oil on top and vinegar below--they really don’t like being together.

This is what happens to all fat and water emulsions unless another substance integrates the two mutually repellent substances. Such a stabilizing third party is known as an emulsifier.

Fortunately, there is an emulsifier already present in one of the ingredients of hollandaise. Lecithin is found in egg yolks, and its chemical nature enables it to pull the conflicting constituents together. One end of a lecithin molecule is fat-soluble and another is water-soluble.

When they come in contact with a mixture of fat and water, lecithin molecules bury their fat-loving (lipophilic) ends in fatty acid molecules, with their hydrophilic ends sticking out into the surrounding water. In other words, they coat droplets of fat with water. This makes them repel the other fat droplets, rather than running together in a fat layer, and the result is a stable sauce.

The sauce doesn’t come together by itself, though. You’ve got to do a bit of cajoling to create the sauce’s peculiar structure.

The technique begins right at the start, as the egg yolks are cooked in a bowl over a water bath--or over direct heat for the more daring--while being beaten until they are thick and creamy and fall from the whisk in a wide ribbon. This ruban consistency creates a uniform base to which the remaining ingredients are added.

Next the yolk mixture is taken off the heat and whipped further as small amounts of melted butter are slowly added to the bowl. This step is where the emulsion really gets started.

As you whisk, the larger particles of fat break down into thousands and thousands of tiny droplets, each coated by emulsifying material and separated from the others by a thin film of liquid. The initial establishment of the emulsion is critical, so the butter must be added very slowly at first. Later, the mixture will accept butter in larger and larger quantities, as long as you whisk after each addition to incorporate the extra fat into the sauce.

It takes more than a strong arm to keep this together, though. There are risks in the process from both a structural and a health standpoint.

Right from the start there is the problem of the emulsion’s temperament. If you add the butter more quickly than the yolks can absorb it, the sauce will break. It will also break if you add more butter than the yolks can handle; a good guideline is six yolks per pound of butter.

Further, if the butter is too hot when you add it to the yolks, they may start to cook, and, again, the sauce will break. But if the butter is too cool, it may solidify and (what else?) the sauce will break, the butter will separate. Try to be careful until you get comfortable with the process.

There is also the concern that eggs may be infected with salmonella bacteria. Salmonella can be killed by cooking the egg mixture to a temperature of 165 degrees and holding it there for several seconds while stirring. The tricky part is that egg yolks begin to harden, or coagulate, at around the same temperature, and any bit of cooked egg will ruin your sauce.

Fortunately, when eggs are mixed with other liquids, like vinegar or lemon juice, they begin to coagulate at 195 degrees, which gives you a little leeway. Be cautious over the heat, though.

But even if your sauce does break, you don’t have to fall apart. Broken hollandaise can often be mended by a few simple procedures.

When the sauce breaks because it is too cold, just heat it up, put a little water in a bowl large enough to hold the sauce, add 1 tablespoon of the broken sauce to the water and beat until it re-emulsifies. If it works, continue beating in the rest of the broken sauce--slowly, of course.

If this doesn’t work, throw it back into the bowl and try again. You can do this about three times, but after that, the mixture will probably have too much water to succeed.

Another way to save a broken hollandaise it to start over with some fresh yolks, cook them to a ruban consistency, then slowly add the broken sauce to them, thus forming a new emulsion. If you can reestablish an emulsion, continue as above until you reach the desired consistency.

At the end of all this, if you succeed, just adjust the seasoning to taste and strain. Then either serve it immediately or hold it over a hot water bath--being careful to keep the sauce from getting too hot or too cold. If you want to prepare the sauce in advance of your other dishes, be aware that in professional kitchens, legal guidelines limit holding a hollandaise sauce to around two hours for health reasons.

Hollandaise goes well with eggs, vegetables and fish. Its cousin bearnaise, made with the addition at the start of a reduction of shallots, tarragon, black pepper and vinegar, goes very well with beef.

HOLLANDAISE SAUCE

2 1/2 cups butter

1/8 teaspoon peppercorns, crushed

1/8 teaspoon salt

3 tablespoons white wine vinegar

2 tablespoons cold water

6 egg yolks

1 to 2 tablespoons lemon juice

Salt

Cayenne

Melt butter in double-boiler. Skim foam from surface, then pour off liquid butterfat, leaving milky water (whey) in double boiler. Discard whey. Keep clarified butter warm.

Cook pepper, salt and vinegar in saucepan until nearly dry. Remove from heat, add water and transfer to stainless steel bowl over hot water bath. Add egg yolks and beat with wire whip until yolks fall from whisk in thick ribbon.

Remove from heat and slowly beat in clarified butter, drop by drop at first, gradually adding more as the emulsion is established. Adjust thickness of sauce by adding lemon juice and season with salt and cayenne. Thin if necessary with water. Strain through cheesecloth or fine sieve and serve or hold for no more than 2 hours.

Variation: Bearnaise sauce. Reduce 2 tablespoons shallots, 1 teaspoon tarragon, 1/2 cup white wine vinegar and 1/2 teaspoon crushed peppercorns instead of salt, pepper, vinegar, and water and continue as above. Garnish with fresh chopped tarragon.

Makes 2 cups.

Each 1-tablespoon serving contains about:

139 calories; 166 mg sodium; 90 mg cholesterol; 15 grams fat; 0 carbohydrates; 1 gram protein; 0 fiber.