Add 5 drops to 1 litre of milk or any other liquid, non-acidic dairy product. Stir well and leave in the refrigerator for 24 hours. After this, at least 80% of the lactose will have been broken down. Add more drops for a higher conversion rate. If you are in a rush and want to use the product immediately, add 5-10 drops per 120ml of milk. This product is not for use in acidic dairy products such as yogurt and buttermilk.