Old-fashioned cultured buttermilk is tangy, mildly sour, and helps give baked goods like pancakes, biscuits, and cake a moist, airy texture.
Mix together starter and milk in a quart-sized glass jar or other similar container.
Cover jar with a towel or coffee filter, securing it with a rubber band, and let it sit in a warm spot for 24 hours or until set (up to 48 hours).
Once set, cover jar with a tight lid, then refrigerate for at least 6 hours.
The buttermilk is now ready to use! Be sure to reserve 1/4 cup of it to culture the next batch, if you want to make more.
Leave in a warm spot to culture for 12 to 24 hours, putting it in the refrigerator once set.
Special Instructions For Using Raw Milk:
If using raw milk, you will need to sterilize the milk before creating the initial buttermilk culture. You will not need to do this for subsequent batches that are made from the initial batch, but it must be done when activating the starter.
I know this may seem unusual and counter-intuitive, especially when we so often tout the benefits of raw dairy, however there is a good reason for it.
You see, raw milk is full of beneficial live bacteria. This will compete with bacteria in the cultured buttermilk powder and compromise the quality and taste of the buttermilk.
To stop this from happening, heat the raw milk to 160 degrees Fahrenheit and let it cool to room temperature before adding the starter powder.
Again, this is only for the first batch of buttermilk (the starter). Subsequent batches of buttermilk can be made with raw milk if desired.
If your buttermilk starts to taste off or is not culturing properly, it may be because the organisms in the raw milk are preventing it from culturing successfully. You would want to pasteurize the milk again at that point.
Homemade Cultured Buttermilk https://traditionalcookingschool.com/food-preparation/recipes/how-to-make-homemade-cultured-buttermilk-5-buttermilk-substitutes/