Why MSG Is The Crucial Ingredient For Copycat Kewpie Mayo

A staple of Japanese kitchens, Kewpie mayo is much more rich and flavorful than your average American store-bought brand. Keeping a little Kewpie in the holster is convenient for throwing together a last-minute sandwich during a busy workday or whipping up some show-stopping deviled eggs for surprise dinner guests who dropped by unexpectedly. But it can be hard to find if you run out. Today's tip comes from our copycat Kewpie mayo recipe by Tasting Table recipe developer Miriam Hahn. Making it yourself saves money as well as a trip to the grocery store.

Perhaps the best part is that this DIY Kewpie mayo only requires six ingredients: sugar, salt, rice vinegar, egg yolks, vegetable oil, and (of course) MSG. Due to its once-unsavory reputation, some foodies who have never worked with it before might be wondering what exactly MSG is. Leave the stigma back in the '60s. It's been proven safe — unless for some reason you choose to guzzle down, like, a lot of it. MSG is back, baybee — and it belongs in your top-tier mayo.

MSG (short for monosodium glutamate) is widely categorized as a "flavor enhancer." It's made from L-glutamic acid, the amino acid by-product of fermenting corn, tapioca, sugar cane, sugar beets, or molasses. And the ingredient is a one-stop umami bomb. Like salt, MSG makes the mouth water, enhancing the way taste buds perceive flavor (with just ⅓ the sodium content of actual salt). To incorporate it into your copycat Kewpie mayo, all it takes is tossing some MSG right into the food processor with your other ingredients and blending away. No extra steps are required.

This lush, smooth, deep yellow-hued Kewpie mayo dupe is the single-ingredient upgrade for your potato salad, egg salad sandwiches, salmon avocado poke bowls, sushi rolls, and okonomiyaki scallion pancakes. Smear it on a grilled cheese sammy or dip your fries in it. MSG is not your average ingredient, and Kewpie mayo is not your average mayonnaise. Unlike American mayo, the tangy, savory, creamy Japanese condiment is made only from egg yolks rather than the entire egg, making for a richer, more luxurious flavor and texture. 

Kewpie brand mayo is made from a combination of pasteurized egg yolks, a secret proprietary vinegar blend (theorized to be rice, apple cider, or malt vinegar rather than white distilled vinegar), vegetable oil, and salt. The version of the mayo that is sold in Japan also includes (you guessed it) MSG. (The American version swaps the MSG for yeast extract and adds sugar.)

Foodies can purchase MSG online or from many local specialty Asian grocery stores. A 4.25-ounce shaker of Spice Supreme MSG costs just $5.40 on Amazon. Or, for diehard Kewpie mayo fans planning to make large batches at a time to keep on hand for different recipes, a 27-ounce bulk container of McCormick brand MSG runs $20.67. Considering that you'll only need ½ teaspoon of the stuff per cup of mayo, it'll last you a long while. Leftover mayo will keep in the fridge for around four days.