Add 5 drops to 1 liter 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 has been broken down. Add more drops for a higher conversion rate. Want to use the product immediately without waiting? Then add 5-10 drops per 120ml of milk product. Do not use in acidic dairy products such as yogurt and buttermilk.