This is my go to since I don't buy whole milk & so far it's been a great substitution for all of my recipes.
To make whole milk out of skim milk and heavy cream:
Use 1½ Tablespoons of heavy cream and the balance skim milk to make one cup.
To make whole milk out of 1% milk and Whipping Cream: Use 1 Tablespoon of heavy cream and the balance 1% milk to make ...
Yeast on the surface of fruit and even flowers is a quite normal occurrence. For a start, I would recommend fruit that are commonly fermented for alcoholic drinks, so my first choice would be apples or grapes - also because they are quite easily obtained. Note that the yeast is on the skins, so using just peels or small fruit like berries or grapes is better....
Dried persimmon have a white bloomy coat or soon will after purchase.
This gal produces 'water yeast' for baking; details about her attempt with persimmon:
A possible answer that is very practical for those who shop in British supermarkets is bilberries. These tend to be covered with a white powder which surely almost certainly contains a lot of yeast. I am in the process of testing this hypothesis.