Why does this recipe call for Kewpie mayo? Can I use regular mayo?

Kewpie is made with egg yolks only (not whole eggs like American mayo), along with rice vinegar and a small amount of MSG. The egg-yolk base gives it a distinctly richer, more custardy texture and a deeper savory flavor. The rice vinegar in the mayo itself adds a softer, more rounded acidity than the distilled white vinegar in brands like Hellmann's. Together this means Kewpie mayo has more fat, more richness, and more umami than American mayo — and those three things are precisely what makes Japanese potato salad taste different from American potato salad even when the other ingredients are similar. Using Hellmann's will produce a fine potato salad; it just won't taste like the dish that went viral. Kewpie is now widely available in the US: most Asian grocery stores carry it, Whole Foods typically stocks it, and it's on Amazon. The 17.6 oz squeeze bottle is the best value if you plan to use it regularly (and you will — it's excellent as a dip, in coleslaw, and anywhere you'd use regular mayo).

What's the half-mash technique and why does it matter?

Half-mashing is the defining textural characteristic of Japanese potato salad. Unlike American potato salad (where potatoes are diced and kept whole) or mashed potatoes (fully smooth), Japanese potato salad falls in between: roughly half the potato mass is pressed into a thick, creamy base while the rest stays in recognizable chunks. The mashed portion acts as a binding agent that holds the dressing to every component — no pool of mayo sitting at the bottom. The whole chunks provide textural contrast and make each bite different. Skipping the half-mash and keeping all the potatoes whole gives you a chunkier, less cohesive result that tastes closer to American potato salad regardless of the mayo you use. The half-mash is why videos of people cutting into Japanese potato salad go viral — the texture looks distinctly different from anything Western.

Why do you add vinegar to the hot potatoes before the mayo?

Hot, freshly drained potatoes are highly absorbent — the starch cells are swollen and porous from cooking. Vinegar added at this stage soaks all the way into the potato flesh, seasoning it from the inside out. If you wait until the potatoes are cold before adding any acid, the vinegar coats only the exterior. The difference in depth of flavor is significant: potatoes seasoned hot taste bright and balanced throughout; potatoes seasoned cold taste flat with an acidic surface. This is the same principle behind dressing pasta while it's still wet from the boiling water — you want the starch to absorb the seasoning rather than the seasoning to sit on top of it.

Can I skip salting and squeezing the cucumber?

You can, and the salad will still taste good the day you make it. But by the next day — and Japanese potato salad is definitely a next-day dish — the cucumber will have released all its water into the mayo dressing. A fresh bowl has a thick, creamy texture; an unsqueezed bowl held overnight develops a pool of watery liquid at the bottom that thins the dressing and makes the salad taste diluted. If you're eating the entire batch the same day and know there won't be leftovers, you can skip the step. Otherwise, don't.

Is ham traditional? What are the other options?

Deli ham is by far the most common meat in Japanese household potato salad — thin-cut sandwich ham, cut into small cubes or strips. It's a mild, slightly sweet pork flavor that doesn't compete with the potatoes or the mayo. Authentic homemade Japanese potato salad almost always has ham. That said, the dish is flexible: bacon (cooked and crumbled) adds smokiness; canned tuna (drained and flaked) is a popular lower-cost variation; imitation crab is another common add-in; and omitting meat entirely with extra corn or edamame is completely acceptable. The egg is more load-bearing than the ham — skipping the egg is a bigger departure from the original dish than swapping the protein.

How long does Japanese potato salad keep in the fridge?

Four days comfortably, five days if it was very fresh when made. The texture actually improves on days 2 and 3 as the potatoes fully absorb the dressing and the flavors meld. By day 4, the cucumber softens perceptibly and the salad starts losing its textural contrast. Day 5 is still safe to eat but the texture is noticeably more uniform. Store tightly covered — potato salad picks up refrigerator odors easily. Do not freeze: the mayo breaks and the potato texture turns grainy after thawing.

What's the best potato variety for this?

Yukon Gold is the ideal choice. Its medium-starch, medium-waxy profile means it's soft enough to half-mash cleanly while still holding together in chunks where you haven't pressed. It also has a natural buttery flavor that reduces how much mayo you need to make the salad taste rich. Russet (high-starch, low-waxy) mashes easily but produces a drier, fluffier result that absorbs the mayo differently — more like a potato pancake texture than a creamy salad. Red potatoes (low-starch, high-waxy) resist mashing and give you a chunkier result that holds together well but doesn't produce the signature creamy base. All three technically work; Yukon Gold is the closest to what you'd get at a Japanese family table or a Japanese grocery store deli counter.

Is this the same as the potato salad at Japanese grocery store deli counters?

Very close. Japanese grocery store potato salad (the kind sold in small tubs at places like Mitsuwa or H-Mart) uses the same technique and the same core ingredients: Kewpie mayo, vinegar-seasoned potatoes, salted cucumber, hard-boiled egg, and ham. Some store versions also include corn, which is a popular addition. The main difference is the scale — stores make enormous batches that sometimes taste more heavily seasoned — and some commercial versions add a small amount of prepared mustard to the dressing for added complexity. The recipe here is faithful to the home-cooking version that TikTok has been recreating and is very close to the grocery store version.

Viral TikTok Japanese Potato Salad Recipe — Kewpie Mayo, Half-Mash Technique

Name: Viral TikTok Japanese Potato Salad — The Kewpie Mayo Secret Most Recipes Ignore
Prep time: 15 min
Cook time: 25 min
Total time: 40 min
Yield: 4
Cuisine: Japanese
Ingredients: For the potatoes:; 1.5 lbs (680g) Yukon Gold potatoes — about 4 medium; Yukon Gold is the right call over russet because their naturally waxy, buttery flesh holds together in chunks while still mashing cleanly where you press; russet mashes to a drier, fluffier texture and produces a less creamy result; red potatoes are waxy enough to resist mashing and give you a chunkier, more American-style salad that works if that's what you want, but it's not the traditional Japanese style; 1 tablespoon rice vinegar — added hot directly to the drained potatoes; hot potatoes absorb the vinegar all the way through instead of just on the surface; this gives the entire salad a background acidity that rounds out the richness of the Kewpie mayo without tasting visibly 'vinegared'; skip this step and the salad tastes flat and one-note; ½ teaspoon kosher salt (for seasoning the hot potatoes); For the cucumber:; ½ English cucumber, or 2 Persian cucumbers — thinly sliced into half-moons, about ⅛ inch thick; thin slicing allows the salt to draw water out quickly and gives the cucumber enough surface area to squeeze efficiently; ¼ teaspoon kosher salt — for drawing water out of the cucumber; see instructions; The rest:; 2 large eggs — hard-boiled and roughly chopped; they contribute richness, mild yolk flavor, and textural contrast; in Japan, the egg is folded in at the same time as the mayo and partially breaks up further when mixed — this is normal and desirable; 3 oz (85g) deli ham, cut into ¼-inch cubes — Japanese potato salad traditionally uses sliced ham (think thin-cut sandwich ham, not thick steak ham); it adds savory depth without competing with the potatoes; any mild deli ham works; omit for vegetarian and add ¼ cup thawed frozen corn instead; 1 small carrot, peeled — either blanched briefly and diced small (classic), or shaved paper-thin with a vegetable peeler for a raw crunch version (see FAQ); The dressing:; 4 tablespoons Kewpie mayo — this is not negotiable; see the note below about why Hellmann's does not work here; 1 teaspoon rice vinegar — this is the second dose of vinegar, added to the dressing itself for brightness; combined with the vinegar you already added to the hot potatoes, the total is balanced — not aggressively sour; ½ teaspoon white sugar — rounds out the vinegar; Japanese home cooking uses a restrained sweetness that you notice only as 'balanced' and miss only when it's gone; 1 teaspoon of sugar is too sweet; zero is too sharp; White pepper to taste — ¼ teaspoon is standard; white pepper has an earthier, more floral heat than black pepper and won't show up as visible flecks; black pepper works in a pinch but changes the visual and flavor slightly; Fine salt to taste — after folding everything together, taste and adjust; potatoes absorb seasoning as they cool so what tasted right warm may need a pinch more cold; Optional additions (pick one or two):; ¼ cup frozen corn, thawed — the most common optional addition in Japanese home cooking; adds sweetness and color; corn and Kewpie mayo are a natural pair; 2 tablespoons thinly sliced scallions — folded in with everything else or scattered on top as garnish; adds mild onion flavor without the sharpness of raw white onion; ½ teaspoon Japanese yellow mustard (karashi) or 1 teaspoon Dijon — whisked into the dressing; adds gentle heat and an almost imperceptible sharpness that makes the whole bowl taste more complex

The Potato Salad Americans Had No Idea They Were Missing

Most people grow up thinking potato salad is cubed potatoes in mayo with mustard. Then they try Japanese potato salad — and the category gets reclassified.

It is not a subtle difference. Japanese potato salad is half-mashed so it’s simultaneously creamy and chunky. It uses Kewpie mayo, which is richer and more savory than American mayo in a way that’s hard to describe until you’ve tasted both side by side. The cucumber goes in salted-and-squeezed, so it’s firm and flavorful instead of watery. The whole bowl tastes balanced — eggy, tangy, slightly sweet, deeply savory — in a way that American potato salad rarely achieves.

TikTok figured this out a few years ago, and the videos keep spreading because the reaction is always the same: “why didn’t I know about this?”

Three Things Most Recipes Get Wrong

1. Using regular American mayo. Hellmann’s is a whole-egg mayo with distilled vinegar. Kewpie is an egg-yolk-only mayo with rice vinegar and a small amount of umami seasoning (MSG). The two are close in total fat per tablespoon, but the yolk-only formula makes Kewpie taste and feel richer, denser, and more custardy — where whole-egg mayo (yolks plus whites) reads lighter and more neutral. The rice vinegar is softer and more rounded than distilled white vinegar. These aren’t subtle differences. Every recipe that says “sub Hellmann’s if you can’t find Kewpie” is technically correct but produces a noticeably different dish.

2. Skipping the salt-and-squeeze step for the cucumber. Raw cucumber is mostly water. You can taste this if you slice one and let it sit on a cutting board for 10 minutes — liquid pools under the slices. All of that water ends up in your potato salad if you skip salting. Fresh, it’s barely noticeable. By the next day (and this is a next-day dish), the dressing is thin and watery and the salad tastes diluted. Salt the cucumber, wait 10 minutes, squeeze it hard. The concentrated cucumber flavor you get after squeezing is distinctly better than raw unsalted cucumber.

3. Not doing the half-mash. Keeping all the potatoes in neat cubes gives you something closer to American potato salad regardless of what mayo you use. The half-mash — pressing down firmly on about half the chunks until they collapse — creates a thick, creamy base that coats every other ingredient and holds the dressing in place. This is the most visually distinct thing about Japanese potato salad and also the most functionally important. It is not an optional flourish.

A Note on Kewpie

Kewpie is widely available now. Most Asian grocery stores carry it. Whole Foods stocks it in the condiment aisle. It’s on Amazon. The 17.6 oz squeeze bottle (the large one with the baby on the label) is the best value and lasts a long time in the fridge. Once you have it, you’ll find yourself reaching for it anywhere you’d use regular mayo — it’s better in coleslaw, better as a dip for fries, and makes an excellent base for aioli.

Viral TikTok Japanese Potato Salad — The Kewpie Mayo Secret Most Recipes Ignore

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Viral TikTok Japanese Potato Salad — The Kewpie Mayo Secret Most Recipes Ignore

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Viral TikTok Japanese Potato Salad — The Kewpie Mayo Secret Most Recipes Ignore

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