Saltpetre is naturally occurring nitrate crystals that are soluble in water. It is found in surface deposits in many countries, or can be induced by mixing decaying organic matter with lime or through chemical solutions.Saltpetre was used in curing but is no longer used commercially (though apparently trace elements are allowed in some jurisdictions) because it can be toxic in quantity. Instead, sodium nitrate or sodium nitrite is used. Saltpetre was also used for gunpowder.
There are actually three types of saltpetre, but the other two (chile saltpetre and wall-saltpetre) never had any application in cooking.
To compare, refer to See Also links below for:
- Sodium Nitrate (NaNO3)
- Sodium Nitrite (NaNO2)
- Potassium Nitrite (KN02)
Saltpetre comes from two Latin words: “sal” for salt, and “petra” for rock.
Its scientific name is Potassium Nitrate KNO3. Its E number is E252.