I've had a lot of trouble finding a quick and easy answer to this question. Wine makers will add these chemical to wine after fermentation to prevent spoilage, and as an antioxidant. You can also add these two ingredients in mead, cider, wine, and beer to stop fermentation in order to hit a final gravity, or back sweeten.
Without the use of a SO2 meter, what is a good approximation of how much potassium metabisulfite/Potassium Sorbate I should add to stop fermentation?
Measurements in grams/gallon please..