Take 1 cup warm full cream or full fat milk. Make sure the milk is warm nor cold neither hot. Start adding vinegar or lime juice little at a time and mix. When you see it start to cuddle immediately stop it. You can even need 1/2 tbsp vinegar or 1 tbsp lime juice depending on the milk and weather. Allow it to rest for 10 minutes and your homemade buttermilk is ready. You can store it in the refrigerator for 3 days. If the water seprates while storing mix it either with whisk or spoon.