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    12 Facts About Mayonnaise That May Surprise You

    Gotta know what goes into that delicious bath tub for your French fries. (Warning: This post contains graphic content.)

    1. The process to make most mayonnaise begins with the chicken (not the egg) in labs where teams of highly trained geneticists design hens best suited for laying eggs.

    Most American egg-laying hens are hatched in hatcheries, not on farms. The largest hatchery is Hy-Line Hatchery in Iowa, which provides female chicks to egg operations in more than 120 countries and has "its own in-house molecular genetics team leading the industry in application of DNA-based technology," according to its website. At hatcheries like Hy-Line, the eggs will remain in incubator machines for about twenty-one days before hatching the chicks that will eventually lay the eggs that become mayonnaise.

    2. Once they have hatched, male chicks are separated from the females and fed through a high-speed grinder.

    Because male chicks cannot lay eggs and do not become the chickens we eat, they serve no purpose in modern agriculture. They are therefore killed by a process called maceration. According to the American Veterinary Medical Association, "death by maceration in day-old poultry occurs immediately with minimal pain and distress." Approximately 21 — 22 million male chicks are macerated each month in the United States, according to the latest United States Department of Agriculture data.

    Animal welfare group Farm Forward is currently petitioning Hellman's and Best Foods to find a way to stop maceration, specifically by using technology to sex the eggs before they hatch. Unilever, which owns Hellman's and Best Foods, did not respond to BuzzFeed's inquiries specifically about maceration.

    Members of the egg industry would be on board with this technology, they say, if it worked. "We’d really like a technique that would allow us to [sex eggs before they hatch]," said Dr. Neil O'Sullivan of Hy-Line. At the moment, though, "the technology hasn’t been developed to be reliable and work properly."

    "It’s one of those practices that the egg industry in the entire world is challenged with, and one we’re trying to address and work on," Chad Gregory, CEO of United Egg Producers told BuzzFeed.

    3. Young female chicks have their beaks trimmed before being moved into small cages.

    "Beak trimming," according to the United States Department of Agriculture, "is a routine husbandry procedure practiced in the poultry industry to prevent feather pecking and cannibalism."

    More than 90% of the country's 296 million egg-laying hens live in cages for most of their lives, which range from 80-110 weeks long. United Egg Producers guidelines state that cage floors must be at least 67 square inches per bird, about 8 by 8 inches, a few inches smaller than a standard piece of paper. In these cages, hens are unable to engage in natural behaviors nesting, dustbathing, foraging, flying, wing-flapping, or walking, which the USDA says, "results in stress, which leads to the expression of harmful behaviors."

    As of January 1, 2012, these cages are banned in Europe.

    Feather pecking and cannibalism, "can lead to suffering and death" but can be mitigated with beak trimming. Most trimming is done on growing farms, where the chicks grow into egg-laying hens. It is usually performed with a hot blade beak trimming machine before the chicks reach ten days old. This method "is likely to be acutely painful" and cause "pain... of a relatively short duration," according to a 2011 article published in Applied Animal Behaviour Science.

    However, Gregory says that beak trimming is a "scientifically humane proven method, similar to trimming one's finger nails."

    A new method using an infrared light is now being used by approximately thirty percent of U.S. egg producers, according to Dr. O'Sullivan, including in Hy-Line's hatcheries. When this infrared treatment is used, "no nerves have infiltrated to the beak tip yet," and therefore this is viewed as a "more humane procedure," O'Sullivan said.

    4. About 80 million eggs, or about 1% of the 8 billion produced annually in the U.S., are used to make commercial mayonnaise.


    While the majority of eggs produced in the U.S. will be washed, weighed, graded and packed into egg cartons, a third of them will be further processed into products like "liquid eggs," says Serena Schaffner of the American Egg Board. Mayonnaise is made from liquid eggs.

    "For liquid eggs, shell eggs go into machines that break eggs and, if necessary, separate the whites and yolks," Schaffner says. Any eggs sold without their shell must also be pasteurized, or heated, to reduce the risk of food-borne illness.

    "Most mayonnaise manufacturers," says Schaffner, "use frozen salted egg yolk for their formulations." The gelatinous quality of the frozen yolk along with the salt give it the desired viscosity for use in sauces and dressings.

    5. Once the eggs have been collected and liquified, they are sent to be processed. This video shows how tanks of liquid eggs, soybean oil, vinegar, salt and other spices, are turned into mayonnaise.

    The relatively simple ingredients go through a high-tech mixing process to turn them into mayonnaise.

    6. Last year, Americans bought approximately 177 million gallons of mayonnaise — enough mayo to fill 268 Olympic size swimming pools or two-thirds of the Empire State Building.

    Dan Meth for BuzzFeed / Original Photo Flickr: atosorigin

    Americans purchased an estimated 1.4 billion pounds of mayo, according to market research company Euromonitor International, coming out to about 4.25 pounds, or just over half a gallon, per person.

    7. In 2013, Americans spent $2 billion on mayo, more than on any other condiment including ketchup.

    Flickr: dunstan

    Yes, more than ketchup, and mayo's growth is outpacing many other condiments. Two big reasons are cited for the growth: One, mayo use has expanded far beyond sandwiches, working its way into everything from pasta salads to sushi. Two, low-fat mayo sales have doubled since 2005, suggesting that health-conscious Americans are starting to get in on mayo-mania.

    8. Even if you say you don't like mayonnaise, it's possible that it's in some of your favorite foods.

    Flickr: quinnanya

    As a Hellman's representative told Today last year, "[Mayo] haters can be won over by realizing that they've probably eaten it and enjoyed it." You may not have noticed the mayo in your Spicy Tuna roll, Subway Tuna sandwich or McDonald's Quarter Pounder Deluxe, but it was in there.

    9. Mayonnaise is not as bad for your health as you might think — if you control the portion size.

    Flickr: su-lin

    One tablespoon of mayonnaise has 90 calories, and if that's all you're using, you're making a relatively healthy choice. "It's high in fat but not saturated fat," says Keri Gans, dietician, nutritionist and author of The Small Change Diet. "The problem with regular mayonnaise is people cannot stick to one tablespoon and therefore they end up adding a lot of calories to a meal."

    Mayonnaise at restaurants, Gans says, can get tricky, though. "If you're going to order out something like a tuna fish salad or an egg salad or a chicken salad, chances are, you're getting a lot of calories and a lot of fat."

    Still though, it's a lesser of evils, says Jayne Hurley of the Center for Science in the Public Interest. "It's good for your heart and is absolutely, head and shoulders above all the other kinds of fats that the restaurant industry is adding to foods like cheese and sour cream and cream cheese."

    10. Unlike many other foods marketed to dieters, low-fat mayo is actually a healthier choice.

    While you can't depend on a restaurant to use a low-fat version, you can choose that option in your own home. Although many low-fat foods make up for lost flavor with sugar, low-fat mayo is an exception. "Low-fat mayonnaise is actually a healthier alternative," says Gans, nothing that Hellman's low-fat version has less than 1 gram of sugar per serving.

    11. Egg-free mayonnaise not only exists, it actually tastes good.

    Courtesy of Hampton Creek Foods

    Hampton Creek's Just Mayo, for example, is made with canola oil, water, lemon juice, white vinegar, and spices. "It’s delicious," says Gans, who, by the way, is not a vegan. A Serious Eats taste test in February found that Just Mayo was even tastier than real mayonnaise.

    Gans warns, though, that egg-free mayo is still high in calories: "Don’t be fooled because now all of a sudden it’s vegan. It’s still 90 calories per tablespoon." Other brands like Earth Balance, Spectrum Naturals, and Vegenaise also make egg-free mayonnaise alternatives. And don't forget about the natural creaminess of an avocado, hummus, or non-fat Greek yogurt if you want to cut calories.

    12. The most delicious and healthiest mayonnaise might be one that you make for yourself from scratch at home.

    The origins of mayo are still fiercely debated — was it invented by a French chef or a Spanish one? But either way, you can still make it at home in just a few minutes with lemon juice, an egg yolk, salt, dry mustard, and oil, and it will taste SO GOOD. If you want to know more about the eggs you're making it from, buy them at a local farmers market where you can ask the person selling them about the chickens they came from.