The Fermentation stopper from Youngs (Potassium Sorbate) (E202) does what it says on the tin. It\'s used to stop the fermentation process after the wine has been bottled and prevents any further fermentation in the bottle. To action this you add 1 gram per gallon to a glass of warm water or wine, once dissolved add to the wine and swirl the wine to distribute evenly. Then you Cover/fit an airlock, swirl the wine again in 24 hours and again 48 hours later. Before you know it, you\'ll be mouth-watering! Fermentation Stopper Features Youngs Fermentation Stopper (Wine Stabiliser) 30grm/ 4065 Potassium Sorbate E202 Store in a cool place. Irritant - Do not breath dust Stops fermentation after the wine has been bottled Youngs\' Ref. MPN: 4065Colour: N/ASizes: 30gPM Ref: 377847