Part 2 - On the second day, there will be lots of little bubbles. Stir the culture. It should have a sour smell & a tangy taste. Add 1/4 cup sorghum flour and 1/4 cup pineapple juice and stir. Let it sit for 12 hours. You should see lots of foaming & bubbling through the sides as well as on the top. Don't be concerned if the culture deflates & loses volume. It should be fine as long as you can see some bubbles and it smells & tastes sour.
Phase 3 - The culture should now have a pronounced, sour, fruity taste and smell. Keep feeding it about every 12 hours until you have a couple cups of starter. This will be your Mother Starter.
Maintaining the Mother Starter:
I usually take a little out every day to make pancakes, waffles, chapatis, or bread. When I do, I replace it with equal amounts of flour and water. I use all different types of flour (buckwheat, rice, quinoa, teff, amaranth, millet). If you aren't going to use it very often, you can also keep it in the fridge. It will become dormant, so you will have to reactivate it with the pineapple juice method from above.
VERY IMPORTANT!!!! The batter should be like thick pancake batter. Technically you are supposed to feed your starter with equal weights flour and water. However, most people I know do not weigh their ingredients. Flour weights vary and everyone measures flour differently (scooping, pouring, sifting). All these factors make a huge difference. If your starter seems hard to stir and too dry just add a little more water. If it is super runny just add a little more flour.
If you are not gluten free, rye flour is the BEST to make starter with.