The Shell Game

Raw egg yolks have been treasured by cooks for centuries because of the way they thicken sauces. Over the last several years, though, it has become clear that for some people, they are no longer safe because of the risk of salmonella.

You can’t live with ‘em; you can’t make mayonnaise without ‘em. Or can you?

With the holiday season coming (and all of the attendant cooking and entertaining that accompanies it), we decided to try to find an alternative, a way of making egg sauces that are safer but still taste the way they should.

The first step was to know the enemy. Salmonella is a bacterium that thrives in poultry. So endemic has it become that it has even been found in the yolks of unbroken eggs, meaning that it is passed from hen to egg.

Salmonella can cause cramps, fever and diarrhea. Salmonella is especially dangerous for the very young, the very old and those with impaired immune systems. For the people in these groups, it can be deadly.

But salmonella can be killed by heat. The American Egg Board says that salmonella organisms will not survive if held at a temperature of 140 degrees or if they reach an endpoint of 160 degrees. “Cookwise” author and food scientist Shirley Corriher recommends heating eggs to 160 degrees for 1 minute. Food scientist and “The Curious Cook” author Harold McGee tells readers that in even the most heavily contaminated eggs, salmonella will be killed if eggs are heated to an endpoint of 182 degrees or if the temperature stays at 160 degrees for at least 3 1/2 minutes.

What makes egg yolks so special in sauce-making is their emulsifying characteristic: They allow oil and water to be beaten into a single uniform substance. That is why oil added to a raw egg yolk forms mayonnaise and why hot butter makes hollandaise.

The good news is that egg yolks will continue to emulsify even after some cooking, as long as the proteins in the yolk have not coagulated. The bad news is that between the safe temperature and the coagulation temperature, there’s not much margin of error. Egg yolks begin to coagulate at 160 degrees.

But there’s a trick that can make things easier. The presence of acid raises the temperature at which the egg yolk proteins coagulate. Add a little lemon juice or vinegar and the coagulation won’t begin until the yolk reaches 170 degrees.

All of a sudden, you’ve got room to operate.

This is not an original discovery. Others have made sauces based on this information, including food scientists McGee and Corriher,the American Egg Board and cookbook legend Julia Child.

What we did was investigate each of their methods and then synthesize them to come up with our own versions.

In trying different mayonnaise recipes, for example, we found that the textures varied widely, depending on the method used to heat the yolks and on the amount of liquid present.

McGee’s method calls for heating yolks with water and lemon juice in a microwave oven until the mixture is near-boiling, visually, when it begins to “heave and bubble.” Oil is then whisked in along with the rest of the flavorings. This has an acceptable texture, but it tastes slightly “cooked,” almost like a hollandaise.

Corriher and the Egg Board use similar sterilization techniques, heating the egg yolks with liquid and acid directly on a stovetop to a lemon curd-like consistency, then beating in the oil. The difference is that Corriher’s recipe calls for more liquid, resulting in a lighter, smoother result. In fact, it was quite close to our “control” batch of homemade mayonnaise.

Hollandaise is not so easy. We made six batches and found that none of them met our taste test. Some were too thick, some were too thin, one was actually sweet and another tasted more like white sauce than hollandaise.

In the end, we wound up taking bits from several of the methods. We cooked whole eggs, chicken stock and lemon juice together, then whisked in cubes of butter. It tastes very close to normal hollandaise, but with no danger of salmonella.

See, you can have your egg sauce and eat it too.

SAFER MAYONNAISE

This recipe uses chemist and food writer Shirley Corriher’s method. Use a mild-flavored oil such as vegetable or canola; unrefined or extra-virgin olive oil produces a less stable emulsion. If you don’t have an electric mixer, a blender or food processor will do. Of course, hand whisking is more than acceptable.

2 egg yolks

1 tablespoon Dijon-style mustard

1 teaspoon white wine vinegar

1 tablespoon water

1 cup oil

Lemon juice

Combine yolks, mustard, vinegar and water in small saucepan. Stir and scrape mixture over very low heat 3 to 4 minutes until mixture is thickened like lemon curd and reaches temperature of 160 degrees for at least 1 minute. Remove from heat and transfer to mixing bowl.

With mixer on medium speed, dribble in oil very slowly, occasionally scraping bowl. As oil and yolks come together, mixing speed can be increased and oil added more quickly. When all oil has been incorporated and mixture is thick and consistency of mayonnaise, about 5 minutes, flavor to taste with lemon juice.

1 cup. Each 1-tablespoon serving:

129 calories; 24 mg sodium; 34 mg cholesterol; 15 grams fat; 0 carbohydrates; 0 protein; 0 fiber.

TIMES SAFER HOLLANDAISE

3 1/2 tablespoons chicken stock

1 1/2 tablespoons lemon juice

2 eggs

2/3 cup butter, cut into 1/2-inch cubes

Hot pepper sauce

Salt

Combine chicken stock and lemon juice in small saucepan. Cook over low heat until liquid begins to bubble around edges, 3 to 5 minutes.

Beat eggs in small bowl until frothy. Whisk 2 tablespoons warm chicken stock-lemon juice mixture into eggs.

Pour eggs into saucepan, whisking constantly, until temperature reaches 150 degrees and mixture thickens, 2 to 4 minutes. Remove from heat and continue whisking 4 more minutes, periodically checking temperature, which must remain 140 degrees or higher. Put saucepan back on heat if temperature falls below 140 degrees.

Continue whisking while slowly adding pieces of butter 1 at a time. Season with hot pepper sauce and salt to taste.

1 1/2 cups. Each 1-tablespoon serving:

49 calories; 74 mg sodium; 31 mg cholesterol; 5 grams fat; 0 carbohydrates; 1 gram protein; 0 fiber.

SAFER ITALIAN MERINGUE

This recipe is from Julia Child’s “The Way to Cook” (Knopf, 1989), with a few minor adjustments to ensure egg safety. Use the meringue to top pies or ice cakes or for baked meringues.

2/3 cup egg whites (4 to 5 egg whites)

Pinch salt

1/4 teaspoon cream of tartar

1 1/3 cup sugar

1/2 cup water

Beat egg whites at slow speed until foamy. Add salt and cream of tartar. Gradually increase speed to high and beat to soft peaks.

Dissolve sugar in water in small saucepan. Bring to boil over medium-high heat. Continue boiling until temperature reaches 240 degrees, about 5 minutes.

As soon as syrup reaches 240 degrees, begin beating egg whites at moderately slow speed and immediately begin dribbling syrup slowly into egg whites. Increase speed to moderately high and beat until egg whites are cool, stiff and shining.

6 to 8 servings. Each of 8 servings:

137 calories; 64 mg sodium; 0 cholesterol; 0 fat; 33 grams carbohydrates; 2 grams protein; 0 fiber.

SAFER BUTTERCREAM FROSTING

3/4 cup water

1 1/2 cups sugar

4 egg yolks

Pinch salt

1 1/2 cups (3 sticks) butter, softened, cut into 1/2-inch cubes

1 teaspoon vanilla extract

Cook sugar and water in small saucepan over medium heat. Stir with wooden spoon until sugar dissolves and mixture comes to boil. Insert candy thermometer, increase heat to high and boil without stirring until thermometer reaches 240 degrees, soft-ball stage, about 7 minutes.

Place yolks and salt in bowl and beat on medium speed 1 minute.

When syrup has reached correct temperature, pour into yolk mixture in thin stream, beating continuously. Place mixing bowl over saucepan of simmering water to make double-boiler and whisk until temperature reaches 145 degrees and remains there 4 minutes.

Remove from heat and beat on medium speed until cool, 3 to 5 minutes. Add butter 1 piece at a time, beating until smooth and fluffy, 3 to 5 minutes. Beat in vanilla.

Keep buttercream refrigerated. Let come to spreading consistency at room temperature before using. Beat again to smooth consistency if necessary before spreading.

3 cups. Each 1-tablespoon serving:

80 calories; 64 mg sodium; 38 mg cholesterol; 6 grams fat; 6 grams carbohydrates; 0 protein; 0 fiber.

NO-EGG CAESAR DRESSING

3 ounces soft tofu

1/2 cup olive oil

2 tablespoons lemon juice

6 anchovy fillets

2 cloves garlic

2 tablespoons red wine vinegar

1/4 cup grated Parmesan cheese

1/2 teaspoon salt

1/4 teaspoon freshly ground black pepper

You could use the near-boiled egg yolks or other sterilized eggs to make a safer Caesar dressing. Another option: Use no eggs at all. Tofu gives the dressing the right creaminess. No, it’s not exactly the same as a true Caesar, but it tastes pretty good.

Process tofu, oil, lemon juice, anchovies, garlic, vinegar, Parmesan, salt and pepper in blender until smooth. Taste and adjust seasoning. Transfer to jar and refrigerate up to 1 week.

1 cup. Each 2-tablespoon serving:

150 calories; 315 mg sodium; 5 mg cholesterol; 15 grams fat; 1 gram carbohydrates; 3 grams protein; 0.02 gram fiber.

NEAR-BOILED EGG YOLKS

We’ve run this method from Harold McGee’s “The Curious Cook” (North Point Press, 1990) in previous years and continue to get requests to rerun the recipe. Use the eggs in hollandaise or mayonnaise or Caesar dressing. If using extra-large egg yolks, use 2 tablespoons plus 2 teaspoons water.

2 large egg yolks

2 tablespoons lemon juice

2 tablespoons water

Beat egg yolks until smooth with fork or wire whisk in 2-cup glass measuring cup or in 2-cup glass bowl. Add lemon juice and beat again. Add water and beat again. Place now-dirty fork or whisk in sink or wash immediately in hot soapy water.

Cover glass cup measure or bowl with plastic wrap or plate, place in microwave and cook on HIGH (100% power) until yolks begin to move. (Watch through oven window, standing back several feet; or after 30 seconds of cooking, open oven door at 10-second intervals to check.)

When yolks begin to move, cook 8 to 10 seconds longer and remove from oven. Beat yolks until smooth with clean fork or whisk. Place now-dirty fork in sink and use clean fork for next step.

Return yolks to microwave and heat on HIGH until yolks begin to move again. Remove and beat vigorously with clean fork or whisk until smooth. Cover and let stand 1 minute.