Contact time required for sanitation with sodium metabisulphite?

Question

My starter brewing kit came with 100g of Sodium Metabisulphite for sanitation. It advises to dissolve 1 tsp per pint of water. However there are no futher instructions.

I don't know how long I need to leave it in contact with my equipment and whether I need to rinse everything thoroughly with water after contact with the sodium metabisulphite solution.

I need to sanitise a 23 litre fermenting bucket and around 50 glass bottles, so is it best to make up a full 23 litres of sanitising solution and fill the bucket entirely, or can I just sloosh a smaller amount around in my bucket?

Answer 1

The references I can find list 5 minutes as the contact time. I would be remiss if I didn't mention that bisulphite (either sodium or potassium) is a very poor sanitizer for beer. It can work with wine becasue the pH of wine is lower than beer and the alcohol content is higher than beer. Those provide additional protection. But for beer, bisulphite will not as well as it does for wine.

Answer 2

It will be ok sanitizing bottles and other small items with the 100g you have, but you'll need a lot more to sanitize a carboy.

I would instead look to get hold of some starsan or iodophor from your LHBS, since these simply need swilling around in the vessel to be sanitized and left for a minute. They are also no rinse.