Japanese cucumber sunomono is a light, crisp salad from Japan made with thinly sliced cucumbers and a sweet-tart rice vinegar dressing. Salting the cucumber first draws out excess water, so the finished salad stays snappy instead of watering down the dressing; family and regional versions vary, and wakame seaweed or sesame is often added.
Ingredients
- 2 medium Japanese cucumbers, about 10–12 inches long total (300 g); or 2 small Persian cucumbers
- ½ teaspoon fine salt (3 g), for drawing water from the cucumbers
- 1 tablespoon dried wakame seaweed (about 2 g), optional
- ¼ cup unseasoned rice vinegar (60 ml)
- 1 tablespoon granulated sugar (12 g)
- 1 teaspoon soy sauce (5 ml), optional, for a rounder, savory flavor
- 1 teaspoon toasted sesame seeds (3 g), for serving
- ½ teaspoon finely grated fresh ginger (about 1 g), optional
Instructions
- Rehydrate the wakame if using. Put the dried wakame in a small bowl and cover it with cool water. Leave it for 5 minutes, until pliable, then drain and gently squeeze out excess water. Cut long pieces into bite-size lengths. Wakame expands as it absorbs water, so start with the small dried quantity listed rather than adding a large handful.
- Slice and salt the cucumbers. Rinse and dry the cucumbers. Trim off the ends, then slice crosswise as thinly and evenly as you can, aiming for slices about ⅛ inch (3 mm) thick. A sharp knife works well; a mandoline can make especially even slices, but use its hand guard. Put the slices in a bowl, sprinkle with the salt, and toss to coat. Let them stand for 10 minutes. This short rest draws out water and seasons the cucumber throughout.
- Mix the dressing while the cucumbers rest. Stir the rice vinegar and sugar together in a small bowl until the sugar is mostly dissolved. Add the soy sauce and ginger, if using. Taste a drop: it should be pleasantly tart, gently sweet, and not dominated by soy. Adjust with a little more sugar if your vinegar tastes sharp, or a teaspoon of vinegar if you prefer a brighter dressing. Do not add extra salt yet; the cucumbers will retain some seasoning after rinsing.
- Drain and squeeze the cucumber. After 10 minutes, a little liquid should have collected in the bowl. Drain the slices, rinse them briefly under cool water to remove surface salt, and drain again. Gather the cucumber in clean hands and squeeze gently over the sink to remove excess water. It should be flexible but not crushed. If you are using a clean kitchen towel, wrap the slices and press gently; avoid twisting hard, which can break them up.
- Dress and chill. Put the cucumber in a serving bowl with the drained wakame, if using. Pour over the dressing and toss until everything is lightly coated. Cover and refrigerate for 15 minutes so the flavors settle. Toss once more before serving, then scatter with sesame seeds. The dressing will collect at the bottom, so a final toss helps distribute it evenly.
Tips
- Choose crisp cucumbers. Japanese cucumbers are long, relatively thin-skinned, and have small seeds, making them a natural choice. Persian cucumbers are a convenient substitute and usually do not need peeling. If using a standard English cucumber, taste the peel first; peel it in stripes or remove it if tough, and scoop out a very watery seed core if needed. Avoid soft cucumbers, which can turn limp after salting.
- Use unseasoned rice vinegar when possible. Seasoned rice vinegar already contains sugar and salt, so using it unchanged can make the dressing too sweet or salty. If that is what you have, omit the tablespoon of sugar at first, mix the dressing, and add small amounts only after tasting. The precise balance depends on the brand, so adjust gradually.
- Keep the slices thin and the squeeze gentle. Even slices take up dressing consistently, while a firm squeeze after salting keeps the salad from becoming watery. Do not press so hard that the cucumber turns limp. Rinsing is useful because the salt amount is intended to draw out moisture, not to season the salad as heavily as a pickle.
- Make it shortly before serving for the best crunch. You can prepare the dressing and rehydrate the wakame earlier, but keep them separate from the salted, drained cucumber until closer to the meal. A brief 15-minute chill is enough to meld the flavors; leaving it dressed for hours makes the cucumber softer.
Serving Suggestions
Serve sunomono cold or cool, in small bowls as a refreshing side dish. Its vinegar brightness works especially well alongside steamed rice and a main dish with savory, grilled, roasted, or simmered flavors. It can also be part of a Japanese-style meal with miso soup, pickles, rice, and a protein of your choice. Because the salad is lightly dressed rather than heavily sauced, it gives the plate a crisp contrast without taking over the meal.
For a simple lunch, spoon it beside rice and a vegetable omelet or a bowl of noodles. At a larger meal, serve it as a small first course or alongside other salads and vegetable sides. Use a slotted spoon if you want to keep extra dressing in the bowl, or serve a little of the dressing with each portion. Sprinkle the sesame seeds just before serving so they stay fragrant and do not soften in the vinegar.
Variations
Make it with wakame: The recipe includes an optional small amount of dried wakame, which gives the salad a pleasantly tender, sea-vegetable texture. If you cannot find wakame, leave it out; the cucumber salad is still complete. Do not replace it with a much larger amount of another dried seaweed, since varieties hydrate differently and can bring a stronger flavor.
Try a more savory dressing: Keep the teaspoon of soy sauce for a subtle savory note, or leave it out for a cleaner vinegar flavor. A few drops of tamari can replace soy sauce, including for a gluten-free option if the tamari is labeled gluten-free. Both alternatives make the dressing saltier and darker, so taste before adding any additional salt.
Change the sweet-tart balance: For a sharper salad, reduce the sugar to 2 teaspoons (about 8 g). For a softer, sweeter dressing, add up to another teaspoon of sugar after tasting. Avoid replacing the rice vinegar with plain distilled vinegar in the same quantity: it is sharper and less rounded. If rice vinegar is unavailable, use a mild white wine vinegar and begin with a little less, then adjust to taste.
Add a little heat or aroma: A pinch of red pepper flakes gives the dressing a gentle kick, while finely grated ginger lends a fresh, warming note. Use either sparingly so the clean cucumber and vinegar flavors remain clear. You can also finish with a few extra sesame seeds. These additions are optional, not requirements for the basic salad.
Storage and Reheating
Refrigerate sunomono within 2 hours of preparing it, in a covered food-safe container. It is best the day it is made, when the cucumbers are at their crispest, but leftovers can be kept refrigerated for up to 2 days. The cucumber will gradually soften and release more liquid; stir before serving, and expect the dressing to taste milder as it mixes with that liquid. For the best texture, keep the sesame seeds separate and add them just before eating.
This is a cold salad, so reheating is not appropriate. Do not leave it at room temperature for serving longer than 2 hours; on a very hot day, return it to the refrigerator sooner. If preparing ahead, mix the dressing and store it covered in the refrigerator, and keep the cucumber separate until shortly before serving. This avoids a watery, soft result and makes it easy to finish the salad after the rest of the meal is ready.
Frequently Asked Questions
Do I need to peel Japanese cucumbers?
Usually not. Their skin is thin and adds color and texture. Rinse and dry them well, then slice. If the cucumbers you have are waxed, unusually tough-skinned, or bitter, peel them fully or remove alternating strips. Persian cucumber skin is also generally tender enough to leave on.
Why do I salt the cucumbers before dressing them?
Salt pulls moisture from the slices, helping them stay crisp and keeping excess cucumber water from diluting the vinegar dressing. A 10-minute rest is sufficient for thin slices. Rinsing briefly and squeezing gently removes extra moisture and surface salt; skipping those steps can leave the finished salad too salty or watery.
Can I make sunomono without wakame?
Yes. Wakame is an optional addition, and cucumber with the rice vinegar dressing makes a satisfying sunomono on its own. If you do use dried wakame, rehydrate it separately and drain it well before adding it. Dried seaweed expands considerably, so measure it before soaking.
Can I use seasoned rice vinegar?
Yes, but check its label before adding sugar or salt. Seasoned rice vinegar is already sweetened and salted, unlike the unseasoned vinegar in this recipe. Start by mixing it with the cucumber without added sugar, taste, and then add sugar only if needed. The dressing may be less adjustable if it is already quite sweet or salty.
Can I prepare it the day before?
You can mix the dressing, rehydrate the wakame, and refrigerate both separately a day ahead. For the crispest result, slice and salt the cucumbers closer to serving, then dress them and chill for 15 minutes. If you must finish the salad in advance, keep it covered and refrigerated and serve within 2 days, knowing the texture will soften.
What should the dressing taste like?
It should taste distinctly tangy, with enough sugar to soften the vinegar rather than make the salad dessert-sweet. A little soy sauce adds savoriness but should not overwhelm the cucumber. Vinegar brands vary, so use the listed amounts as a starting point and make small adjustments before tossing everything together.
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