From EC Kraus Website.. A good place to buy stuff.
E.C. Kraus’ wine conditioner (SGR310) reduces harshness in a finished wine by sweetening it to a desired finish. Turn a dry wine into a sweet wine or use just enough wine conditioner to take the dry edge off your wine.
This conditioner will reduce any wine’s aging time by making it drinkable sooner. It is very convenient and easy to use and comes with complete directions.
Directions: Before adding conditioner to any wine verify with a hydrometer that its fermentation is complete. The wine should be clear and moved off of any sediment into a clean container and ready to bottle. Add the Wine Conditioner directly to the wine and don’t forget to stir thoroughly to evenly dispense the sugars.
Dosage: Wine Conditioner can be added at any dosage to personal taste but be careful not to add too much. You may want to take a measured sample of the wine and add measured amounts of Wine Conditioner to the sample to establish a dosage that is to your liking. This will eliminate any risk of over-sweetening the entire batch.
Minimum Dosage: If less than 2 ounces per gallon is used then also add
Potassium Sorbate at the rate of ¼ teaspoon per gallon to eliminate any chance of re-fermentation.
Ingredients: Liquid invert sugars (fructose and glucose), potassium sorbate.
I would get a measured amount and test with it then work out your ratio to add, so you do not mess up the complete run.