Russian Summer Soup (Okroshka): A Classic Cold Kvass Soup

Russian summer soup, usually called okroshka, is a chilled combination of potatoes, hard-boiled eggs, cucumber, radishes, and fresh herbs in tangy kvass. This version uses kvass, a fermented bread drink, for its gently tart, savory base; regional and family versions also use kefir or other sour dairy drinks.

Ingredients

3 medium waxy potatoes, about 1 lb (450 g), scrubbed
4 large eggs, about 7 oz (200 g) without shells
2 cups diced cucumber, about 9 oz (250 g), from 1 large cucumber
1 cup thinly sliced radishes, about 4 oz (120 g)
1/2 cup thinly sliced green onions, about 1 oz (30 g)
1/3 cup chopped fresh dill, about 1/3 oz (10 g), plus extra for serving
6 1/3 cups (1.5 L) chilled, savory kvass
1/2 cup sour cream, about 4 oz (120 g), plus more to serve
1 teaspoon prepared mustard, about 5 g
1/2 teaspoon fine salt, about 3 g, plus more to taste
1/4 teaspoon ground black pepper, about 0.5 g
4 cups (950 ml) cold water and ice, for cooling the cooked potatoes and eggs

Instructions

Cook the potatoes. Put the scrubbed potatoes in a saucepan and cover with cool water. Bring to a boil, then reduce the heat to maintain a steady simmer. Cook until a knife slides into the center without much resistance, about 18–20 minutes depending on size. Drain and let them cool enough to handle. Peel if you like, then cut into small, even cubes. Smaller pieces make the soup easier to eat with a spoon, but avoid cutting them so tiny that they crumble.
Hard-boil the eggs. While the potatoes cook, place the eggs in a second saucepan and cover with cool water. Bring the water to a boil, turn off the heat, cover the pan, and let the eggs stand for 10–12 minutes. For this cold soup, cook whole eggs until the yolk and white are firm. Transfer them to the cold water and ice, then peel and dice once cool. The potatoes and eggs cook at the same time; the 25-minute cook estimate includes bringing the pans to a boil and cooking them.
Prepare the vegetables and herbs. Dice the cucumber, slice the radishes and green onions, and chop the dill. Keep the pieces roughly similar in size to the potato and egg so every spoonful has a balanced mix. If your cucumber has a very seedy, watery center, scrape out some of it before dicing; this helps keep the finished soup crisp rather than diluted.
Mix the solid ingredients. Put the cooled potatoes, eggs, cucumber, radishes, green onions, and dill in a large bowl. Add the salt and pepper and fold gently with a broad spoon. Taste a piece of potato: it should be lightly seasoned before the liquid goes in, since cold dishes can taste less seasoned than warm ones.
Make the kvass base. In a separate bowl, whisk the sour cream and mustard until smooth. Whisk in a small splash of the chilled kvass to loosen the mixture, then gradually whisk in the rest. Pour this dressing over the chopped ingredients and stir gently. Taste and add a little more salt, pepper, or mustard if needed. Kvass varies in sweetness and saltiness, so adjust the seasoning to the bottle you have rather than adding a large amount at once.
Cool and serve. If the potatoes or eggs are still warm, spread them in a shallow dish and let them cool in the refrigerator or in the prepared ice water before mixing; do not leave cooked ingredients at room temperature for an extended period. Refrigerate the assembled soup for at least 45 minutes, until thoroughly cold. Stir before serving, since the chopped ingredients can settle, and finish with dill and a spoonful of sour cream.

Tips

Choose a savory kvass. Kvass can be sold in different styles, and some bottles are noticeably sweet. Look for a plain or traditional savory version if possible. If your kvass tastes sweet, start by mixing it with only part of the chopped ingredients, then add a little more mustard and salt to balance the flavor. Avoid pouring in extra vinegar automatically; it can make the soup sharp rather than pleasantly tangy.
Keep the cut consistent. Small, even pieces are a practical detail, not just a presentation choice: they distribute the potato, egg, and crunchy vegetables throughout the broth. Use a sharp knife and dice the cucumber and potato to about 1/4–1/2 inch (6–12 mm). Slice radishes thinly so they add a peppery bite without dominating a spoonful.
Season in stages. Salt the chopped ingredients lightly, then taste again after adding the kvass. Different kvass brands have different levels of sweetness and salt, and chilled soup can seem less salty than it will after a few minutes at the table. Add salt in small pinches, letting it dissolve before deciding whether the bowl needs more.
Keep everything cold. Chill the kvass before you begin, and use an ice bath for the eggs if you are short on time. Warm ingredients can make the soup lukewarm and soften the cucumber. If you are making it ahead, you can refrigerate the chopped ingredients and kvass separately, then combine them shortly before serving for the freshest crunch.

Serving Suggestions

Serve okroshka cold in individual soup bowls, with extra sour cream and chopped dill at the table. A little extra green onion or a few thin radish slices make a fresh garnish, and a small dish of mustard lets each person sharpen their own portion. Rye bread is a natural accompaniment; dark or seeded bread also works well for scooping up the last of the broth. The soup is filling enough for a light lunch, especially with bread, but it can also be served in smaller bowls as the first course of a summer meal.

Before ladling, stir from the bottom so the potatoes and vegetables do not remain in a layer beneath the liquid. If the soup seems too concentrated after chilling, loosen it with a little more cold kvass, a spoonful at a time. If it seems too thin, serve each portion with an additional spoonful of sour cream rather than adding a large amount of sour cream to the entire batch. Put the bowl back in the refrigerator between servings on a warm day.

Variations

Use kefir instead of kvass. For a creamy, tangier style, replace the kvass with 5 cups (1.2 L) plain kefir and thin it with up to 1 1/3 cups (315 ml) cold water until it reaches a pourable consistency. Start with less water and adjust to taste. Kefir makes a thicker, dairy-forward soup rather than the malty, lightly fermented flavor of kvass. This is a useful option when kvass is hard to find; unsweetened plain yogurt thinned with cold water can work too, although it is usually thicker and more tart.

Add cooked meat. Some versions include diced cooked beef or a mild cooked sausage. Use about 1 1/2 cups (225 g) in place of some of the potatoes or simply add it to the bowl. Keep the meat chilled and cut it into small cubes. If cooking meat specifically for the soup, cook it safely before cooling: whole cuts of beef should reach 145°F (63°C) with a 3-minute rest, while ground meat should reach 160°F (71°C), checked with a food thermometer. Fully cooked, commercially prepared sausage can be diced cold according to its package directions.

Adjust the vegetables and herbs. Add a little more radish for extra pepperiness, or use less green onion for a milder result. Parsley can replace some of the dill, though dill gives the soup its familiar fresh aroma. For a lighter, crunchier bowl, increase the cucumber and reduce the potato slightly; for a more substantial one, keep the full amount of potato. These proportions are flexible, but keep enough kvass to coat and surround the chopped ingredients.

Storage and Reheating

Refrigerate the soup within 2 hours of preparing it, in a covered container at 40°F (4°C) or colder. It is best in texture during the first 1–2 days, when the cucumber and radishes remain crisp, but leftovers can generally be kept refrigerated for 3–4 days. Use a clean spoon each time you serve it, and discard any portion that has been left at room temperature for more than 2 hours, or more than 1 hour in temperatures above 90°F (32°C).

Okroshka is meant to be served cold, so reheating is not customary. If you expect to have leftovers, storing the chopped ingredients separately from the kvass-and-sour-cream mixture helps the vegetables stay crisper; refrigerate both promptly and combine portions as needed. If you do choose to warm a leftover portion, heat it evenly to 165°F (74°C), checked with a food thermometer, though the texture and flavor will be different. Do not freeze the assembled soup: cucumber and sour cream can separate or turn watery after thawing.

Frequently Asked Questions

What is Russian summer soup called?

It is commonly called okroshka, a name associated with the chopped ingredients in the bowl. Recipes vary by region and household. Kvass-based versions are well known, while other versions use kefir or another tangy dairy drink, and the vegetables and additions can differ.

What does kvass taste like?

Kvass is a fermented drink traditionally made from bread, often rye. It has a mild malty, tangy flavor and may be slightly sweet or fizzy, depending on the style. In this soup, its flavor is softened by sour cream and balanced by fresh vegetables, mustard, and herbs. Check the label and taste it before mixing, because sweetness varies.

Can I make okroshka without kvass?

Yes. Plain kefir thinned with cold water is an easy substitute, and plain yogurt with water can work if you cannot find kefir. Both alternatives make the soup creamier and more tangy, with less of kvass’s malty character. Start with a smaller amount of water, then thin the base until it is easy to ladle.

Can I prepare it ahead of time?

Yes. Cook and cool the potatoes and eggs, chop the vegetables, and refrigerate the components in covered containers. For the crispest result, keep the kvass mixture separate and combine everything 30–60 minutes before serving. You can also assemble the soup earlier in the day and chill it, but the cucumber and radishes soften gradually as they sit in the liquid.

Why does my okroshka taste bland?

Cold food can need more seasoning than warm food, and kvass differs in sweetness and saltiness. Stir the soup, then taste the broth and a spoonful with the chopped ingredients together. Add salt a pinch at a time, followed by a little mustard or green onion if it needs more bite. Chilling the finished soup for at least 45 minutes also gives the flavors time to mingle.

Should I peel the potatoes and cucumber?

Peel the potatoes if you prefer a softer, more uniform texture; thin-skinned waxy potatoes can also be left unpeeled after a thorough scrub. Cucumber usually does not need peeling, especially when its skin is tender. If the skin is thick or bitter, peel it in alternating strips, and remove an especially seedy center to keep the soup from becoming watery.

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