Polish Żurek Recipe - Sour Rye Soup

Discover my family recipe for delicious Żurek Soup, a classic dish from Poland, also known as Fermented Sour Rye Soup. This comforting, hearty soup has become one of my all-time favourites, thanks to its deep, savoury flavour and unique tanginess. While there are many ways to prepare Żurek, each region and home has its own twist, but the secret to its distinct taste always lies in the fermented rye starter.

Once you try this traditional Polish dish, I believe you’ll share my love for it! Żurek is particularly popular during the Easter holidays, but its warm, satisfying flavours make it perfect to enjoy all year round. Perfect to enjoy with Homemade Sourdough Bread. My guide to Polish food sets out what else belongs on the Easter table, and what gets cooked at Wigilia.

“As an Amazon Associate I earn from qualifying purchases.”

PPin it

What is the base ingredient for Żurek Soup?

If you’re eager to craft your own Polish Żurek Soup, the key to unlocking its unique, tangy flavour lies in the fermented rye starter. This is the essential base ingredient that gives Żurek its distinctive sourness and deep, savoury character. While preparing the starter is simple and requires only a few basic ingredients - like rye flour, water, and some spices - patience is a must, as it takes about 5-7 days to ferment properly.

For those in a hurry, ready-made Żurek soup bases are available at European supermarkets or online. But trust me, there’s nothing like the rich, authentic taste of a homemade starter that you’ve prepared yourself. Taking the time to ferment your own base not only lifts the flavour of the soup but also brings a sense of tradition and accomplishment to your cooking experience.

So, if you’re up for the adventure, I encourage you to try making your own fermented starter. You’ll be rewarded with a bowl of Żurek that’s packed with genuine Polish flavours! Do roboty!

What is Żurek? - Traditional Polish Sour Rye Soup Explained

Żurek, a traditional sour rye soup, holds a special place in the hearts of the Polish people. Originating from the unique tang of fermented rye flour starter, known as “żur”, this soup combines the robust flavours of potatoes, smoked sausage (Kiełbasa), smoked bacon (Boczek), eggs, and aromatic herbs. It is a favourite for Easter, served with sausage and a boiled egg, sometimes in a hollowed-out bread bowl. In my house we make it for Christmas too, and on cold winter evenings when nothing else will do.

What are the types of Polish Żurek?

• Żurek Staropolski - This is the most traditional version of the Polish soup, prepared with vegetable bouillon as a base, fermented rye starter, Polish smoked sausage (Kielbasa), and smoked bacon, known as Boczek. It’s served with a boiled egg and sourdough bread.
• Żurek Benedyktyjski - This variation of the soup is prepared in the same way as Żurek Staropolski. It is finished with tablespoon of sour cream, which are mixed with a ladle of the soup to prevent curdling. Serve it with a side of quark cheese.
• Zalewajka - is a traditional Polish soup that is distinctively prepared with a water base, rather than using vegetable bouillon. This choice of base allows the natural flavours of the other ingredients to shine through more prominently.
• Barszcz Biały - a distinct variant of the traditional soup, is primarily prepared using a wheat flour starter as opposed to the more commonly used rye flour. Despite this key difference, the majority of the other ingredients remain similar. This substitution of wheat flour lends a unique texture and a slightly different flavour profile to the soup, while maintaining its much-loved classic taste.

A Closer Look at the Ingredients

• The zakwas (rye starter) Everything else is supporting cast. Rye flour and water left to sour for the best part of a week is what makes żurek żurek, and there is no shortcut that tastes the same. Type 2000 wholemeal rye is what Polish bakers use; a plain wholemeal rye will do.
• Biała kiełbasa The white sausage, raw and unsmoked, is the default in Poland and it is what gives the soup its particular savoury weight. Polish shops sell it fresh; if you cannot find it, see the substitutions below.
• Smoked boczek Polish smoked belly bacon, fried until the fat renders. That rendered fat is where a lot of the flavour comes from, so do not drain it away.
• Marjoram Not oregano, and not optional. Marjoram is the herb Poles reach for with pork and rye, and żurek without it tastes like it is missing something you cannot name.
• Cream Stirred in at the end to soften the sourness. Double cream is the most forgiving because a higher fat content resists splitting.
• Hard-boiled eggs and potatoes Traditionally halved eggs go into the bowl at serving and potatoes go in on the side or in the pot. Both turn a sharp soup into a proper meal.

Equipment You Will Need

Ingredient Substitutions

• No biała kiełbasa? The most common problem outside Poland. A good plain raw pork sausage with no herbs is the closest thing, and a Cumberland or a plain butcher’s banger works. Keep some smoked kiełbasa in the pot as well, because it is the smoke that reads as Polish.
• No boczek? Smoked streaky bacon, or a piece of smoked pancetta. You want it smoked and you want the fat, so avoid lean back bacon.
• Rye flour Wholemeal rye is what you want. Be aware that a starter made with wheat flour gives you barszcz biały, white borscht, which is a different soup from the same family rather than a substitute for this one.
• Cream Soured cream, or 18 per cent cooking cream, both work but both split more easily than double cream because there is less fat protecting them. Temper whichever you use.
• Vegetable or meat stock The recipe uses vegetable stock, which is what both Polish sources I checked use. Chicken or a light pork stock is equally traditional and gives a rounder soup.
• Vegetarian żurek Leave out the sausage and bacon, build it on a good mushroom and vegetable stock, and add dried wild mushrooms with the starter. Smoked paprika or a little smoked salt stands in for the smoke. The sourness carries the soup, so it survives the loss better than you expect.

How to Make Żurek, Step by Step

Full quantities are in the recipe card below. Żurek is really two jobs: a rye starter that ferments for the best part of a week, and a soup that comes together in about an hour once you have it. Start the zakwas first and the rest is straightforward.

Part One: The Rye Starter (Zakwas), 5 to 7 Days Ahead

1. Boil the water and let it cool. This is not fussiness. Chlorine in tap water inhibits the microbes you are trying to encourage, and boiling drives it off. Cool it to room temperature before it goes anywhere near the flour.
2. Mix the starter in a sanitised jar. Rye flour, the cooled water, crushed garlic, bay and allspice, stirred together with a clean spoon. Clean is the operative word at every stage: you are cultivating one thing and keeping everything else out.
3. Cover it with cloth, not a lid. A paper towel or cloth held on with a band lets the ferment breathe while keeping dust and flies out. Seal it airtight and you trap the gas it needs to release.
4. Leave it at room temperature, out of direct sun, and stir every other day. Five to seven days and it is ready. It should smell sharp and sour, pleasantly so, like sourdough rather than anything spoiled. Your kitchen needs to be above about 22°C for this to get going, which is the thing almost nobody says. “Room temperature” means different things in different houses, and a kitchen sitting at 19°C will leave you staring at a jar of flour and water for a week wondering what went wrong. An airing cupboard, near a radiator or on top of the fridge all work. What you are feeding is lactic acid bacteria, near relatives of the ones that turn milk into yogurt and soured cream, and they are happiest somewhere near blood heat and merely sluggish when cold. That is the useful part: a cold kitchen stalls a zakwas, it does not kill it. Move the jar somewhere warmer and give it another day or two before you decide it has failed.

Part Two: The Soup

1. Make the vegetable broth. A litre of water with the diced carrots, quartered onions, chopped celery and sliced leek. Bring it up, then let it simmer for about an hour.
2. Strain it, but keep the carrots. They go back into the finished soup. The rest of the vegetables have given everything they had and can go.
3. Fry the diced bacon. Four or five minutes over a high heat until the fat has rendered out and the pieces have crisped.
4. Bacon, carrots, sausage and marjoram into the hot stock. Bring it to the boil, then down to a simmer for five minutes. Marjoram is not optional in a żurek, it is the herb that makes it taste Polish.
5. Now the starter, and go slowly. Whisk the zakwas together with the sediment at the bottom of the jar, picking out the spices. That sediment is where most of the flavour lives, so do not pour off the clear liquid and leave it behind. Add it to the soup gradually and let it simmer until it thickens, tasting as you go. Sourness is a matter of taste and you cannot take it back out once it is in. Stir constantly and keep the heat low the moment it goes in, because the flour drops straight to the bottom and catches, and a scorched base makes the whole pot bitter. Pour in about two thirds, taste, then decide: sourness is personal and starters vary depending on how long and how warm they fermented. You can always add more, but you cannot take it out.
6. Lift the sausages out, slice them, put them back. Easier than trying to cut them in the pot, and it means everyone gets a fair share.
7. Temper the cream before it goes in. Mix the cream with a ladleful of the hot soup in a separate bowl first, then pour that back into the pan. Add cold cream straight to hot soup and it curdles into threads. This one step is the difference between silky and split. Lower-fat creams need this more than double cream, not less, and the reason is worth knowing. When cream heats, the surface of each fat globule grabs hold of some of the milk protein, which leaves less of it free to clump into threads. A thin cream simply does not have enough globules to mop up that protein, so it curdles where double cream, at around half fat, sails through. In a soup this sour, that margin is everything.
8. Serve it properly. Ladle over cooked potatoes, garnish with parsley or dill and plenty of black pepper, and add halved hard-boiled eggs for żurek z jajkiem.

Recipe Card for Polish Żurek

Variations

• Żurek staropolski The old-Polish version, and the one most people mean. Vegetable stock, smoked kiełbasa and boczek, served with a boiled egg and sourdough bread.
• Żurek w chlebie Served in a hollowed-out round sourdough loaf. Cut the top off, pull out the crumb leaving a good centimetre of wall, and warm the shell in the oven for a few minutes so it does not go soggy the moment the soup goes in.
• With horseradish The most-recommended addition among Polish cooks by a wide margin. A tablespoon of freshly grated horseradish stirred in with the starter gives it a warmth underneath the sourness. Worth trying once even if you leave it out afterwards.
• With dried wild mushrooms A grandmother-era addition. A few dried porcini soaked and added with their soaking water give the soup a deeper, earthier base.
• Zalewajka A thinner country cousin built on water rather than stock, usually with potatoes cooked in the soup itself.
• Żurek and barszcz biały Not the same thing, though they are close relatives. Barszcz biały is made with a wheat starter and comes out milder and paler; żurek is rye and sharper. If you have a taste for sour soups, my barszcz czerwony is the beetroot one.

Storing, Freezing and Reheating

• The soup keeps two to three days in the fridge, and it is genuinely better on day two once the sourness has settled into everything else.
• Reheat gently and do not boil it hard once the cream is in, or it can split. Low heat, stirring, until it is steaming.
• Freezing works best without the cream. Dairy can split on thawing, so if you know you are freezing a batch, hold the cream back and stir it in when you reheat. It keeps about three months.
• The starter keeps two weeks in the fridge once the garlic, bay and allspice have been strained out, which matters: whole garlic sitting in a jar for weeks is the one part of this worth being careful about. Strain it, bottle it, keep it cold.
• Leftover starter freezes for up to a year, which is the easy answer if you have made more than you need. Freeze it in the quantity you use so you are not thawing the lot.
• Potatoes and egg go in at serving, not into the storage container. Potatoes turn grainy in the fridge and a boiled egg sitting in hot soup goes rubbery.

🍽 Żurek wants a halved hard-boiled egg in the bowl, diced boiled potatoes either in the soup or alongside, and good rye or sourdough bread to mop it up. For Easter or a proper occasion, serve it in a hollowed-out sourdough loaf. A little grated horseradish on the side lets people sharpen their own. If you are building a Polish table around it, my bigos is the natural thing to follow it with, and my bigos builder will size it for however many are coming.

FAQ for Żurek

How can I tell if my starter is ready?

The starter will emit a tangy aroma complemented by the pleasant scents of spices and garlic, and the liquid will separate from the solids.

What to do when foam appears on the surface of the starter?

A light, pale foam on top is normal fermentation and you can simply stir it in or skim it off. Mould is a different thing entirely. If you see anything fuzzy, or any patch of grey, green, pink or black, throw the whole batch away and start again. Do not try to scoop mould off and use what is underneath, because the threads run down through the liquid even when the surface looks clean afterwards. The usual causes are a jar or spoon that was not properly clean, or grain sitting above the water line, so keep everything submerged and covered with a cloth.

Is it normal for the starter to have a strong smell?

Yes, a tangy or sour smell with aroma of garlic and spices is normal. However, if it smells unpleasant or mouldy, it’s best to discard it and start fresh.

What should I do if my starter isn’t fermenting?

Nine times out of ten it is too cold rather than dead. The bacteria doing the souring slow right down in a chilly kitchen, so move the jar somewhere genuinely warm, an airing cupboard or the top of the fridge, and give it another two days. Check the water as well: chlorinated tap water that has not been boiled and cooled will hold the ferment back from the start. Only start again if it smells genuinely wrong rather than merely quiet, or if you can see fuzzy grey, green or pink mould, which is never worth rescuing.

How should I store the starter?

If you don’t plan to make Żurek right after fermenting, don’t put the jar in the fridge immediately. First, you need to remove the garlic, bay leaves, and allspice from the starter. A fine mesh strainer might be helpful for this. Pour the starter along with the flour into a bottle or jar and keep it in the fridge for up to 2 weeks.

Should I add potatoes to żurek?

Many readers find żurek lacks body without them - add peeled, diced potatoes and cook until soft, either in the soup or served in the bowl. It turns a thin soup into a proper, filling meal.

How do I stop the cream from curdling?

Temper it, whichever cream you use. Take a ladleful of the hot soup, whisk it into the cream in a separate bowl, then pour that back into the pot with the heat off. It takes ten seconds and it is the difference between a smooth soup and a curdled one. Worth knowing that lower-fat creams, the 18 per cent carton type, actually split more readily than double cream rather than less, because there is less fat holding the emulsion together, so those need tempering most of all. Never let it come back to a hard boil once the cream is in.

My żurek is too sour, how do I fix it?

The most common complaint with this soup, and the fix is dilution rather than sugar. Add more stock a ladle at a time until it sits where you want it, and if that thins it too far, let it simmer uncovered to reduce again. A little extra cream at the end softens the edge too. Polish cooks generally do not sweeten żurek, so reach for stock before you reach for honey. Next time, add the starter in stages and taste as you go rather than tipping the whole jar in.

My żurek is too thick, or too thin. What went wrong?

Too thick usually means too much starter for the volume of stock. Loosen it with more stock and give it a few more minutes. Too thin is the opposite problem, and it is often because the clear liquid was poured off the starter and the flour sediment left behind. Whisk the jar properly next time, sediment and all, because that flour is what gives the soup its body. You can rescue a thin one by simmering it uncovered to reduce.

My żurek is not sour enough. Can I still save it?

Yes. Add more starter, gradually, and let it cook through for a couple of minutes each time so you are tasting the finished flavour rather than raw flour. If you have run out of starter, a spoonful of brine from a jar of fermented cucumbers is the traditional cheat and it works. A weak result usually traces back to a starter that was not fermented long enough or was kept somewhere too cold.

What is biała kiełbasa, and what can I use instead?

Biała kiełbasa is Polish white sausage: raw, unsmoked, seasoned with marjoram and garlic, and it is the default in almost every Polish żurek. Polish delis and the world food aisle of larger supermarkets stock it, usually fresh. If you cannot get it, use a good plain pork sausage without herbs, and keep some smoked kiełbasa in the pot alongside, because the smoke is a big part of what makes the soup taste Polish.

Why has my starter not started fermenting?

Almost always temperature. A żurek starter needs somewhere above about 22C, and plenty of British kitchens sit at 18 to 19C, especially in spring when people tend to make this for Easter. Move the jar to an airing cupboard, near a radiator or on top of the fridge, and give it another couple of days. The other usual causes are chlorinated tap water that was not boiled first, or a very refined flour: wholemeal rye from a small mill ferments far more reliably than supermarket white.

Can I use my bread sourdough starter instead?

You can get a soup out of it, but it will not be quite żurek, and the reason is that the two starters are looked after with opposite aims. A bread baker keeps a starter cool and refreshes it constantly in order to hold the bacteria back and keep the yeasts strong, because bread needs gas, and the acid the bacteria make weakens gluten. A zakwas wants precisely what the baker is suppressing: as much sourness as it can get, and no leavening at all. A rye zakwas is fermented specifically for this, with garlic, bay and allspice in the jar, and it is sharper and more aromatic than a bread starter. If you want to speed things up rather than replace the process, a couple of tablespoons of active sourdough starter stirred into a fresh zakwas will get it going in about three days instead of the usual week.

Can I freeze żurek, and how far ahead can I make it?

It freezes well for about three months, and it is better to freeze it before the cream goes in, because dairy can split on thawing. Stir the cream through when you reheat. Made ahead, it keeps two to three days in the fridge and genuinely improves overnight, which makes it a sensible thing to cook the day before Easter rather than on the morning itself.

How much żurek do I need for a crowd?

Reckon on about 300 to 400 ml a head as a starter, or half a litre if it is the main event with bread and potatoes. This recipe makes six starter-sized portions. It scales cleanly, but scale the starter with everything else rather than doubling the soup and keeping the same zakwas, or you will end up with a large pot of pleasant but unremarkable broth.

PPin it

A Few Words from the Chef

Żurek is my favourite Polish soup, no contest. I loved it when other people made it for me, and now I love making it for other people. It is well worth preparing your own ferment starter if you can, that is what really sets it apart. Smacznego!

Check out my other Recipes: