So here’s a quick rundown:
Take the fruit, toss it in a jar, and add 30 to 40 milliliters (2–3 tablespoons) of water to the mix. Stir it to see it become a little bit cloudy, which is the yeast.
Then, add the same amount of flour to make loose, wet dough. No need to get fancy as old flour works just fine, and white flour, according to Sudeep, works best. Non-organic and gluten-rich flour does the job too.
Keep the mix warm—not hot, not cold, but warm. 12 hours later, you should see bubbles, which are caused by the yeast inside the mix.
24–48 hours later, the paste should loosen up, at which point you need to take a small bit of this mix and add it to 30–40 milliliters of water. Add flour and repeat the process. This time around, it should come to life and the bubbles should appear faster.
This guy's helping by teaching us how to make our own yeast. Excellent information, and I'm bookmarking the method, just in case. Thanks Izi!