WHICH CAME first the chicken or the nog? Christmas morning the nog is traditionally first. While the kids are anxious for the ho-ho-ho, a quick shot of eggnog can provide fortification, breakfast and a little hair of the dog that bit the night before -- a thick layer of cream, calories and eggs to coat your stomach and sooth the noggin.

Before the nog there was the noggin, an old English ale measurement for one fourth pint. Ale was mixed with milk, soon sherry replaced the beer and by the 18th century in America, bourbon replaced sherry. Eggs were added, the milk thickened to cream, and the punch served in a small cup or noggin. Ergo, eggnog.

Others say syllabub came first -- an old English drink, supposedly named because it was a combination of milk and wine from Sille; and "bub", the Elizabethan colloquial for a bubbling drink. Some give the credit to a German egg punch still popular in Germany today.

Nonetheless, one form of eggnog or another is seen in many homes during the holidays. There are as many variations as there are stories of its origin -- some made with yolks and no whites, some as thick as mousse made with heavy cream, rum, bourbon and brandy, or some combination of two or all of them.

The Food Section held a blind tasting of 16 different eggnogs -- half of them homemade, the other half store-bought. This is what we discovered.

The Store Bought: We tasted the nonalchoholic varieties (Lucerne, Giant, Borden's, Embassy, High's and Shenandoah's, average price $1). Of these, the tasters grudgingly prefered Safeway's Lucerne brand and Giant's. However, the overall opinion was that they tasted like "baby formula," "butterscotch" or "powered milk." Adding liquor to the nonalcholic brand doesn't help. They already contain artificial alcohol flavorings. Safeway's eggnog ice cream is the same as above, just frozen.

We also tried two pre-mixed commercial brands, 30 proof alcohol (rum, brandy and bourbon mixed). Although the price was fair ($3.99) the tasters all agreed they were chalky and medicinally spiked. The two brands we tried -- Overbrook and Old New England -- evoked unflattering comments like: "formaldehyde kick," "bitter and hot" and "two sips and down for the count."

Homemade: Mrs. C. of Springfield, Va., wrote and told us: "Important to use 100-proof booze [bourbon], else the yolks don't 'cook' and the result is an eggy taste." We appreciate the mail, Mrs. C., but the 100-proof bourbon was far too sharp for our tasters and didn't blend evenly with the taste of cream and eggs. One a second tasting we tried 86 proof bourbon and got a more mellow blend. Whether the eggs were left to soak or "cook" overnight in the liquor, or not, there was no discernible difference.

We were also sent a few "authentic southern recipes" that called for heavy cream and no milk thinner. When chilled, it was impossible to pour and more like a bourbon mousse than a punch. The best combination was half and half mixed with whipping cream.

A note on the nutmeg: Fresh grated is always better. Put a few whole nutmegs in a small bowl with a grater and let people help themselves. Don't overdo it. "The essential oils of nutmeg contain about 4 percent of a highly toxic substance, myristicin, which taken in excessive amounts (2 or more tablespoons) can cause . . . hangovers, headaches, nausea and dizziness," according to Frederic Rosengarten Jr. who wrote "The Book of Spices." Then again, you can always tell them it was the nutmeg.

When serving eggnog, ladling from a punch bowl into cups is preferable to pouring from a pitcher. The punch tends to settle after a few hours -- the cream and whipped egg whites settling on the top, and the liquor on the bottom. To keep the eggnog cold, the punch bowl and cups should be iced in the freezer. When ready to serve, set the bowl on a cloth (high holiday spirits don't help ladling accuracy) so the spills don't eat through the table, and surround the bowl with cracked ice.

One reader, Marian Carlsson of Lexington, Va., suggests: "If eggnog starts to cloy halfway through the holidays, and you think you can't swallow one more mouthful of anything so thick and sweet and rich, lighten it up by mixing it with an equal portion of ginger ale."

Below are the recipes that received the highest points on the taste test. KOSHLAND'S EGGNOG (30 small servings) 12 eggs, separated 1 1/2 cups sugar 9 ounces bourbon 9 ounces brandy 1 quart whole milk 1 pint heavy cream 1 1/2 ounces rum Nutmeg to taste

Beat the egg yolks until thick and lemon-colored.Slowly beat in 3/4 cup sugar, a little at a time. Combine the bourbon and brandy and slowly add to the yolks, beating after each addition. Beat the egg whites until stiff, add remaining sugar, a few tablespoons at a time then carefully fold into yolk mixture.

Pour the milk, 1/2 cup at a time, into the eggnog, mixing gently after each addition. When the milk has all been stirred in, add the cream, 1/2 cup at a time. Then add rum 1 tablespoon at a time to prevent curdling.

For an interesting variation, substitute 2 cans undiluted frozen cranberry juice for the milk and cloves for nutmeg, or 2 cans undiluted orange juice for the milk and a few scrapings of orange peel.

From "The Christmas Cookbook," by Zella Boutell

This recipe originally appeared on a Seagrams' label in the early 1950s, but was altered over the years. FINALLY EGGNOG (15 servings) 6 egg, separated 3 tablespoons sugar (or more to taste) 10 ounces of 86 proof bourbon 2 ounces brandy 1 pint half and half 1 pint whipping cream Nutmeg

Slowly beat egg yolks and sugar together. Gradually add liquor and continue beating. Slowly add half and half and mix thoroughly. Set aside. In a separate bowl, beat cream until peaks form and fold into mixture. Beat egg whites until stiff. Fold into yolk mixture. Sprinkle with freshly grated nutmeg and chill.