This is a quicker way to make laben / buttermilk than my other recipe & is a great way to have a constant supply. Make sure the buttermilk is as fresh as possible. Also make certain your mason jar is spotlessly clean! The amounts here are just your base, as long as you have a ratio of 1 part buttermilk to 4 parts milk you'll get great results. For anyone in the UK wanting to try this, I use a 2 pint bottle of whole milk & a 284ml container of St. Ivel Cultured Buttermilk. I then stand the mix in my kitchen for 24 hours & bingo! Note: If you would like a reallllly thick buttermilk, use 1 part buttermilk & 3 parts milk.