Stuff:
Two sanitized jars, from the pantry
Two sanitized jar lids, from the pantry
Viili culture
Spoon
Milk
Room temperature cupboard, or countertop if you do not have animals

What to do with the stuff:

1. Put two spoonfuls of viili culture into a sanitized jar.
2. Half-fill the jar with organic, semi-fat milk.
3. With a spoon, thoroughly mix the viili culture and milk.
4. Put the jar into the cupboard and leave it uncovered and undisturbed for 12 hours.
   More than +/- 30 minutes is suboptimal.
5. Remove the viili from the cupboard.
6. Put a lid on the viili and put it into the fridge for at least 6 hours.
7. Ideally, repeat every 24 or 48 hours.
   If left too many days, the viili becomes acidic and you have to make a couple batches before you can eat it again.
   Worst case, the culture dies and I will have to order a new culture.