White Grape Juice Concentrate in a 250 ml pouch by Handcraft Supplies. Grape juice concentrate can be used in wine recipes to improve the quality of your homemade wine and aid healthy fermentation. It can be added to basic wine kits for a better end result. It can also be used in homebrew country wines. We particularly recommend adding it to your grape juice when making wine from garden grapes to improve the final wine. Simply add to the fruit must prior to fermentation. Contents are intended to make up to approx. 4.5 L volume, which is a standard UK demijohn size.