Steam sterilisation
Short, high-heat steam that cuts microbes on spice without chemical residues.
Also: steam treatment, spice pasteurisation, irradiation
Steam sterilisation exposes spices to saturated steam for seconds to minutes, usually followed by rapid drying and cooling. It cuts bacterial and mould counts, including Salmonella, with little loss of flavour compared with long heating. It leaves no chemical residue, and so is a preferred alternative to gas treatment in the European Union and many other markets. Producers in India, Vietnam and Indonesia have invested in steam plants for pepper and herbs. Irradiation is another method used in some countries, with labelling rules. A well-run line balances microbial safety against loss of volatile oils, and the best plants measure both.