Humble mayonnaise is America's third favorite condiment (after salsa and ketchup), according to a 2003 survey by the Association of Dressings and Sauces. It gives a lift to sandwiches, from bologna to BLTs, and is probably among your refrigerator staples. But what is it, exactly? Mayonnaise is made by beating oil (vegetable, soybean, or olive) into a base of egg or egg yolk and acid (such as vinegar or lemon juice) — a concoction that is, for mayo aficionados, far more than the sum of its parts.

Even so, real mayo has assumed black-sheep status in the condiment family, due to its high fat content and the notion that it's filled with cholesterol. This is a misconception, says Colleen Pierre, R.D., co-author of Giant Book of Kitchen Counter Cures (Jerry Baker Books, $20, www.amazon.com). "Mayonnaise has egg yolk in it, but it contains very little egg; it's mostly made of healthy soybean or canola oil." But which brand can best liven up your lunch?


BEST OVERALL: TRADER JOE'S REAL MAYONNAISE
The Spread: Preservative-free Trader Joe's mayo got rave reviews from Real Simple's panel of palates. Samplers loved the "rich, creamy" texture and the "lasting flavor," which had hints of egg and vinegar. Note: This brand is sold only at the nationwide grocery chain (see www.traderjoes.com for store locations).
The Skinny: A 1-tablespoon serving has 12 grams of fat (1.5 grams saturated), 10 milligrams of cholesterol, 70 milligrams of sodium, 100 calories.

HELLMANN'S/BEST FOODS REAL MAYONNAISE
The Spread: Richard Hellmann, who served the popular condiment at his New York City deli, started bottling it in 1913, becoming the first to introduce mayo to the masses. (The brand is called Best Foods west of the Rockies.) Real Simple testers liked the "creamy texture" but tastewise found it "light, bland," and lacking "distinctive flavor."
The Skinny: A 1-tablespoon serving has 11 grams of fat (1.5 grams saturated), 5 milligrams of cholesterol, 80 milligrams of sodium, 100 calories.

KRAFT MAYO REAL MAYONNAISE
The Spread: The label declares this "the creamiest of national brands," but tasters said they found the mayonnaise inside the jar "less creamy" than the competition, more heavy than heavenly. Testers also said Kraft Mayo was low on flavor — although one rated it "pretty good."
The Skinny: A 1-tablespoon serving has 11 grams of fat (1.5 grams saturated), 5 milligrams of cholesterol, 75 milligrams of sodium, 100 calories.

HELLMANN'S/BEST FOODS LIGHT MAYONNAISE
The Spread: Hellmann's Light delivers 40 milligrams more sodium per serving than Hellmann's Real Mayonnaise, but it cuts the calories and the fat in half. Testers said this lighter spread was surprisingly tasty, with a mouth feel just like that of "classic regular mayo." Even better, it was free of chemical flavors — a common downfall of reduced-fat foods.
The Skinny: A 1-tablespoon serving has 5 grams of fat (1 gram saturated), 5 milligrams of cholesterol, 120 milligrams of sodium, 50 calories.

KRAFT MAYO LIGHT MAYONNAISE
The Spread: Tasters said that Kraft Light delivered a "good kick" and a "tangy" bite. But not everyone loved the light version's strong taste — some found it overbearingly "sour." It contains only slightly more sodium than regular Kraft Mayo (and a little less cholesterol), but it cuts the fat by close to two-thirds and the calories by more than half.
The Skinny: A 1-tablespoon serving has 4 grams of fat (0.5 gram saturated), less than 5 milligrams of cholesterol, 90 milligrams of sodium, 45 calories.