Foam Appeared in Your Sauerkraut Barrel?
Many people notice during winter that sauerkraut in barrels starts to spoil, even though there is still a lot of it. The appearance of foam, a change in smell, or cloudy liquid are the first signs that fermentation is out of control.

TL;DR
- If sauerkraut brine foams excessively, add 5-10 grams of vinobran (potassium metabisulfite) to preserve freshness and prevent spoilage.
- Common reasons for spoilage include high room temperature, insufficient salt, light exposure, and cabbage not fully submerged.
- A 4% salt solution (400g salt per 10 liters of water) can be used to top up the brine.
- Transferring sauerkraut to a clean barrel, pressing it down to keep it submerged, is vital as exposed cabbage spoils fastest.
- Store barrels in a cool, dark place, avoid direct sunlight, and maintain a stable, low temperature.
- Periodically check the brine, add salt if needed, ensure cabbage stays submerged, and maintain barrel cleanliness.