Step 1

In a mason jar or other glass container, thoroughly mix the starter and milk. Cover with a coffee filter or piece of cheese cloth (do not seal tightly with a lid) and leave to culture out of drafts at a warm room temperature (between 70-78°F is recommended) until milk has clabbered (10-24 hours).

Step 2

To test if the milk has thickened, tip the jar slightly. It should move away from the wall of the jar as a single mass. Just as with yogurt making, once the milk sets, it will get more tart the longer you allow the culturing to continue.

Step 3

Refrigerate to halt culturing for at least six hours. Stir before using.