I presume Sodium metabisulphite is fairly harmless but wouldn't qualify
as organic. What would organic wine-makers use to sterilise their
equipment?

Janet G

Fairly harmless??

Not according to the chemical industry.

SAFETY DATA SHEET
SODIUM METABISULPHITE Page 1

Whoa everyone...
Sodium MetabisulphIte (with an "I") may be nasty but the chemical put in
wine is Sodium MetabisulphAte ("A").
Different chemical.