Yeasts are used to produce "alcoholic beverages" / beer / wine, to bake, yogurt/cheese, etc....
Going to a shop and buy some baker's yeast is easy but not a long term solution, at least the ones I know (and have access) have a short expiration date.
In a situation where:
- going to a shop" is not an option
- trying to "freeze/preserve" some backup batch is not an option
Is it possible to "obtain/grow" yeasts for this uses at "home" easily? Which kind? And how?
Basically I want to know how easy/hard it is to obtain this kind of yeasts in the "nature" (from "nothing".... )?