American Kewpie Mayo is Missing One Key Ingredient

Kewpie mayonnaise is a favorite among chefs — and for good reason. “It is the iconic bottle of my childhood, having grown up in a Taiwanese-American household,” says Eric Huang, chef and owner of Pecking House in Brooklyn, New York. “I don’t like American mayos, as they are too sweet for me,” adds chef Claudette Zepeda. “At my house, we use [Japanese Kewpie] and my kids refuse all other brands.”

Kewpie is tangy, rich, and, unlike other American mayos on the market, packed with umami thanks to one key ingredient: MSG.

Monosodium glutamate, or MSG, is a seasoning made from glutamic acid, an amino acid that is naturally found in ingredients like cheese, soy sauce, and nuts. When used as a food additive, MSG is a flavor enhancer, increasing the savoriness of any dish it touches. MSG is what makes Kewpie stand out among other store-bought mayos — it can give any average potato salad or tomato sandwich an extra oomph. 

The traditional formulation, which comes in a squishy plastic tube covered with a plastic bag with Kewpie’s iconic, red and white baby logo, has been produced in Japan since 1925. In the early 1990s, Kewpie Corporation began exporting mayonnaise to the United States — it gradually gained popularity but has continued to be far more difficult to source than, say, Duke’s and Hellmann’s. To this day, you’re far more likely to find Japanese Kewpie at an Asian market than at your neighborhood’s grocery store. 

But in 2019, Q&B Foods, an American division of Kewpie Corporation based in Irwindale, California, announced that it would produce Kewpie stateside. The packaging is different — it’s still in a tube, but that tube is more dense and comes without the bag. The “Kewpie Mayonnaise” logo is in the same font, but the Japanese translation is missing. There’s still a baby on the label, but while the Japanese version has its full, cartoon body outlined, the baby on the American version is depicted from the neck-up, giving a little wave. The forefront of the American Kewpie bottle is the image of a sandwich filled with (as far as we can tell) lettuce, pickles, deli meat, tomatoes, and a generous drizzle of mayo. But, both versions have one essential feature in common: a star-shaped tip under the cap, bringing a touch of whimsy any time Kewpie is used. 

The American version of Kewpie is available at major grocery store chains around the country, so when I needed to buy a bottle for Food & Wine’s mayonnaise taste test, I simply went to my local Whole Foods. But when it came time to try the mayo, it tasted … different. It still had a custard-like consistency, but that complexity and punchy umami that I’ve come to expect from Kewpie was far less intense. I turned the bottle around and found that, to my surprise, the ingredients were entirely different from the original, Japanese Kewpie mayonnaise. I decided to investigate.

According to Kewpie’s website, here are the ingredients in Japanese Kewpie: Vegetable Oil (Canola Oil, Soybean Oil), Egg Yolk, Vinegar, Salt, Monosodium Glutamate, Spice, Natural Flavor.

And here are the ingredients in American Kewpie: Soybean Oil, Egg Yolks, Water, Distilled Vinegar, Salt, Sugar, Mustard Flour, Red Wine Vinegar, Rice Vinegar, Yeast Extract, Natural Flavors

There’s a lot to unpack here. The first ingredient listed for both mayos — the oil — shouldn’t make much of a difference. While the Japanese version uses a combination of canola and soybean oil and the American version just uses soybean, both soybean and canola are neutral oils, so the change isn’t likely impacting the mayos’ flavor or consistency. Notably, the third ingredient in the American version is water — an ingredient missing from the Japanese version. This could explain why the American Kewpie is slightly more runny than its Japanese counterpart. 

As for the vinegar, the American Kewpie lists distilled, red wine, and rice vinegars, while the Japanese version just lists “vinegar.” According to Kewpie’s website, the company uses a “unique blend of vinegar” which other sources claim is rice vinegar, red wine vinegar, apple cider vinegar, and distilled vinegar. The exclusion of apple cider vinegar makes the acidity on the American version slightly less sophisticated and complex.

But here’s where it gets really juicy — the American Kewpie has sugar, while the Japanese Kewpie does not. I’m going to hypothesize that this is due to the American preference for a sweeter mayonnaise. The two most popular mayos in the country, Hellmann’s and Miracle Whip, include sugar in their formulations. Why shouldn’t Kewpie follow the same model? 

Another ingredient found in American Kewpie and not the Japanese version is mustard flour. Usually, mustard flour is used for its yellow color rather than its flavor. This makes sense, as Japanese egg yolks are generally more orange than American eggs due to their red-hued feed which includes paprika. This gives their mayo a distinct, butter-yellow color. If the American-made Kewpie is intending to mimic that color while still using American eggs, mustard flour would be a great tool for doing so.

Now we’ve come to the biggest difference of them all: American Kewpie does not use monosodium glutamate. In an email to the Chicago Tribune in 2019, Q&B Food’s then director of sales Terry Dunseith said that the American Kewpie had the “same great taste as the original from Japan, but without the MSG that many Americans tend to avoid.”

Although MSG is used to make Doritos, Campbell’s chicken noodle soup, and Slim Jim’s, many Americans have the inaccurate presumption that the ingredient is harmful. In an essay for Food & Wine, writer Mari Uyehara explained how this misconception has been steeped in xenophobia ever since 1968, when a doctor published a letter in the New England Journal of Medicine about experiencing pain and weakness after eating at a Chinese restaurant. Readers, and later, scientists, began to theorize that MSG was the cause of his “strange symptoms.” Although MSG has never been proven as a harmful ingredient (the U.S. Food and Drug Administration and the American Chemical Society has stated that moderate consumption of MSG is perfectly safe), many Americans still avoid it, especially when it is associated with Chinese restaurants and Asian food in general. 

2019 was a long time ago — in the last five years, there has been much more discourse surrounding the negative connotations around MSG — and yet, the American version of Kewpie has the same formula as the day it was invented. Instead of MSG, there is yeast extract, which Dunseith described as “another umami secret.” Ironically, monosodium glutamate is a naturally occurring chemical in yeast extract. There is a detectable hint of umami in American Kewpie, but it is far more understated than the Japanese version.

“In my opinion, [the American Kewpie] is less flavorful, likely due to the increased use of MSG in the Japanese version,” says 2023 F&W Best New Chef Edgar Rico, owner of Nixta Taqueria in Austin. “It definitely tastes more subtle. Not in a good way,” adds Zepeda. 

To be clear, the American version of mayonnaise is still solid — it’s well-balanced, creamy, and still more nuanced than many of its competitors. But if you’re looking for the mayo that chef’s around the world hype up; the one that can truly give a punch of umami to any dish, I recommend seeking out Japanese Kewpie. If you can’t find a bottle at a grocery store in your area, follow Zepeda’s lead and order a six-pack online.