I am going to try a gallon of apple juice cider. I have a sachet of Mangrove Jacks M02 cider yeast which came recommended. However the sachet is for 5 gallon! which I don't want to attempt for a first shot at it. The yeast sachet is 9gms so can I use about 1.5gms and if so whats the safest way to save the rest.