What other sources are there for yeast without purchasing specific supplies of any kind?
I’ve done several lactose fermentation experiments and am currently playing with figurative fire by washing and running fruits through a food processor, letting them go active in a (burped) container and then adding them to other fruit juices. Currently I have a small apple for yeast that I added to pealed lemons and some lemon juice. I have no expectations for the results, and intend on buying nothing.
I experimented with wild yeasts.
If you can’t get/don’t want to use lab yeasts (dried in bag), the best bet is to start with about 1l of fruit juice or wort, put it in Mason jar or some container with larger opening and let it sit outside in garden or on a window over night.
Put it inside, let it ferment completely (it will take about 7days) in somewhat warm room (20 - 25°C). Taste it and smell it if it is good (no off smells and off flavors like acid, bitter or rotten). And use it as starter.
I messed with yeasts about 2 years ago with petri dishes, isolates, microscope and stuff but this basic recipe will do it. Bear in mind that it is about 50/50 if you get good or bad strains so make multiple batches and use only the most promising ones.
Yeasts are pretty much everywhere so you will most likely catch something, but you don’t want any bacteria or mold.
I will try to find yt vids about this (someone recommended me sth on reddit) and post them there.
https://www.youtube.com/watch?v=WtXrsvNLCxk&list=PLZ3Z2428mCTqDFK-3ZSNpZBXJfTaMtRXE