Why Do Your Jars Explode? Choosing the Right Salt for Home Canning
Every summer — the same story
Tens of thousands of home canners in Ukraine face the same problem every year: cucumbers go soft, cabbage develops slime, and jars explode right in the cellar. Recipes are time-tested, sterilization is followed — yet results are disastrous.
The cause often lies not in the canning technique, but in the most basic ingredient — salt.
Salt and canning: basic chemistry
Salt's action in canning is based on osmosis. NaCl creates a hypertonic environment where most pathogens cannot multiply. Lactic acid bacteria remain active and produce lactic acid that additionally protects the product.
Key requirement: salt must be as pure NaCl as possible. Any impurities can disrupt this balance. Canning requires salt with NaCl content of at least 97%, preferably above 98%.
The problem with sea and lake salt
Sea salt is produced by open-air evaporation. Along with NaCl, numerous impurities remain:
- Magnesium (MgCl₂) and calcium (CaCl₂) salts
- Potassium and sulfates
- Algae particles and organic residues
- Microplastics (found in 100% of sea salt samples)
But the main danger is chemical additives.
Potassium ferrocyanide (E536): the invisible enemy
After Ukraine's largest producer "Artemsil" shut down, supermarkets filled with imported salt — mainly Turkish and Egyptian. It pours perfectly, never clumps — but that's the warning sign.
The reason: anti-caking agent E536. In canning, it:
- Disrupts natural fermentation in brine
- Suppresses lactic acid bacteria
- Triggers uncontrolled putrid fermentation
- CO₂ accumulates — lids bulge or blow off
Comparison table
| Parameter | Rock salt (Romania, Poland) | Sea / lake (Turkey, Egypt) |
|---|---|---|
| NaCl content | 97–99.5% | 85–95% |
| Extraction | Mining from deep deposits | Open-air evaporation |
| MgCl₂, CaCl₂ | Minimal | Significant |
| Anti-caking (E536) | Typically absent | Frequently present |
| Microplastics | Absent | Found in 100% of samples |
| For canning | ✅ Ideal | ⚠️ Risky |
Rock salt: why depth means purity
Rock salt (mineral halite) formed 250–300 million years ago. Over this time, it purified itself from organics under immense geological pressure. Unlike sea salt, it doesn't contact modern pollutants. Mined from 42–300+ meter depths with only mechanical processing.
Practical recommendations
- Read the ingredients. Only NaCl. No E-additives.
- Avoid E535, E536, E538 — ferrocyanides that destroy fermentation.
- Skip iodized salt — iodine suppresses fermentation.
- Choose coarse grind (#1 or #2) — less likely to contain anti-caking agents.
- Prefer Romanian or Polish rock salt — EU standards, no chemical additives.
At soltis.com.ua — Romanian and Polish rock salt without additives. Wholesale prices from 5 bags.