50 grams Potassium Sorbate
Potassium Sorbate is the potassium salt of sorbic acid, and is a mild, yet effective preservative.
You will need 1/4 teaspoon of granules per 1 litres of concentrate.
To use, simply add a dash of hot water to the granules to dissolve, then pour it into your soapnut liquid after straining.
Comes in a resealable clip bag. Total net weight 50g (approximately 22 teaspoons).