Name: Kiseli kupus
Prep time: 30 min
Total time: 504 h 30 min
Yield: about 2 kg fermented cabbage
Cuisine: Serbian
Ingredients: 2000 g firm white cabbage, trimmed, cored and finely shredded; 45 g canning or pickling salt, 2.25% of cabbage weight

Yield about 2 kg fermented cabbage

Preparation 30 minutes

Cooking 0 minutes

Passive 30,240 minutes

Ingredients ↓

Overview

Kiseli kupus with 2.25% salt and controlled shredded-cabbage fermentation

Kiseli kupus is one of Serbia's defining winter ingredients, but the term covers more than one household process. Whole cabbage heads are commonly soured in barrels, while shredded cabbage can be fermented in the sauerkraut style. This recipe deliberately uses the shredded method because salt concentration, submersion and temperature can be specified precisely for a small home batch.

Salt is measured by weight rather than by spoons or handfuls: 45 g for 2000 g prepared cabbage, which is 2.25%. As the salt is worked through the shreds, it draws water from the cabbage. The mixture should become glossy and pliable, and squeezing a handful should produce enough brine to begin covering the packed cabbage.

Packing is not cosmetic. Firm pressure removes large air pockets, and a food-safe weight keeps every shred below the brine. The low-oxygen environment favours the lactic-acid fermentation that produces the clean sour flavour. Exposed cabbage at the surface is a weak point, so submersion has to be maintained for the entire ferment rather than checked only on the first day.

Temperature controls the pace. At 21–24 °C, allow at least 21 days and expect full fermentation to take about three to four weeks. Bubbling is normal during active fermentation and should diminish as the cabbage becomes fully sour; the aroma should be cleanly acidic, never rotten.

Fermentation is not made safe by time alone. Persistent foul odour, sliminess, clearly rotten tissue or other unmistakable spoilage is a reason to discard the batch, not to correct it with extra salt, vinegar or cooking. Once fully fermented, the cabbage stays covered by brine and moves to 4 °C or below, where cold storage becomes the control for the finished food.

Practical

ControlMeasure salt as 2.25% of the prepared cabbage weight.
ControlKeep every shred below the brine for the entire fermentation.
ControlHold the ferment near 21–24 °C rather than relying on a vague room-temperature instruction.
ControlUse bubbling and clean sour aroma as progress cues, while treating foul odour, sliminess or rotten tissue as discard signals.

Ingredients

Fermentation

2000 g firm white cabbage, trimmed, cored and finely shredded
45 g canning or pickling salt, 2.25% of cabbage weight

Directions

Salt and pack

Salt the cabbage by weightWeigh 2000 g prepared shredded cabbage and 45 g pickling salt, then work the salt through the cabbage in batches until it begins to release juice. The cabbage is glossy, pliable and a handful squeezed firmly releases brine. Salt measured by weight supports a reproducible fermentation concentration.
Pack out the airPack the salted cabbage tightly into a clean food-grade fermentation vessel, pressing until brine rises above the cabbage. No dry air pockets remain and liquid begins to cover the packed cabbage. Firm packing helps create the low-oxygen environment used by lactic-acid fermentation.
Keep every shred submergedPlace a clean food-safe weight over the cabbage so all solids stay below the brine throughout fermentation. Every cabbage shred remains below the liquid surface. Complete submersion limits exposed surfaces where spoilage organisms can grow.

Ferment and refrigerate

Ferment in the working rangeRest the submerged cabbage at 21 °C to 24 °C for at least 504 hours (21 days), then continue as needed until the ferment is fully sour; full fermentation in this range typically takes about 3 to 4 weeks. Active bubbling develops, the brine becomes tangy and the cabbage gradually changes from raw-green aroma to a clean sour-cabbage aroma; by full fermentation bubbling largely ceases. The 21–24 °C working range supports a steady household sauerkraut fermentation while the 21-day minimum keeps the cabbage in the active process long enough to assess full souring.
Refrigerate after souringWhen fermentation is complete, transfer the covered vessel or packed cabbage to the refrigerator at 4 °C or below. The finished cabbage remains submerged in brine and is held cold after fermentation. Cold storage slows further fermentation and controls the cabbage after the active ferment.

Practical

Practical guidance

Use a scale for both cabbage and salt, and use a vessel large enough to leave headroom for brine movement. During active fermentation, keep the weight and any surfaces above the brine clean. A clean sour smell and steady bubbling are normal progress cues; sliminess or a clearly rotten smell is not. After fermentation, take portions with clean utensils and keep the rest submerged and refrigerated.

Control points

Cabbage stays dry above the liquidGuidance: It was packed loosely, insufficient juice was expressed or the weight does not hold the solids down.Adjustment: Press the cabbage firmly under the existing brine and adjust the clean food-safe weight; do not leave exposed shreds.
Ferment becomes slimy or develops a clearly rotten odourGuidance: Spoilage has overtaken the intended fermentation.Adjustment: Discard the batch rather than attempting to rescue it by adding acid, salt or heat.

Nutrition

Serving size100 g drained fermented cabbage
Caloriesapproximately 20 kcal
Carbohydratesapproximately 4 g
Proteinapproximately 1 g
Fatapproximately 0 g
Fibreapproximately 3 g
Sodiumapproximately 890 mg

These figures are approximate and can change with ingredient brands, trimming, liquid retention and portioning.

Allergens and food safety

Use 45 g pickling salt for 2000 g cabbage, keep the cabbage completely submerged in a food-grade vessel and ferment at 21 °C to 24 °C. If persistent foul odour, sliminess or clearly rotten tissue develops, discard the batch. After full fermentation, keep the cabbage covered by brine at 4 °C or below.

FAQ

Why is the salt weighed?

A 2.25% salt concentration is material to the fermentation. Weighing both cabbage and salt is more reproducible than spoons or handfuls.

What if the brine does not cover the cabbage?

Press the cabbage under its existing brine and adjust the clean food-safe weight. Exposed shreds should not be left above the liquid.

Result: Kiseli kupus finishes cleanly sour and crisp-tender, with shredded cabbage fully fermented under brine and kept submerged after transfer to cold storage.

Key: Measure salt as 2.25% of the prepared cabbage weight.