Finding Natural Yeast Sources
Some time back, I posted a video from a Japanese website. A woman there was interested to create breads from natural yeast sources. She became well known for it, and was interviewed for a cooking program. Her method is precisely like the form found at the link below.
[link to www.tacticalintelligence.net
In this link they use apples, in her version she used raisins. Raisins produced the most “fizzing action” so it was assumed that due to the higher fermentation that more yeast was present. That's a good link by the way, and kudos to the writers of that article.
I know raisins work. Naturally this is the basis for making wine. Yeasts from certain regions in France are known to interact with the grapes grown there, and due to this difference plus the style of making the wine, you get a different tasting wine. I guess that there could be a discernible taste difference in a trained chef's tongue to detect the differences in say the yeast produced for bread in Missouri versus Georgia.
Using raisins has been a tried and true method in Europe. I found a video from Austria that uses this method to make yeast bread too. Regardless as the tactical intelligence article discusses, any fruit or grain that has some sugar in it will interact with the wild yeasts in the air.
That method is utilized by incarcerated people to make jailhouse wine called Pruno. They take whatever fruit/grain/vegetables they can find, say ketchup, or like the pioneers...corn stalks...and use that to get an additional harvest of ethanol.
Now Peace Corp volunteers take old knowledge from pioneer skills and combine that with modern techniques and teach those methods in 3rd world nations in order to improve their lives. They might help with wells, or sanitation or making some chemical from local ingredients to improve a mortar so they can build stronger wall.
But they also might be in a country where it might be frowned upon to drink or purchase ethanol. So if they want to do that, they might have to make it themselves. A common way is to make raisin wine since they ferment consistently, and the ingredients are so simple to find anywhere.
Three parts to it. You don't need to add the yeast. It will naturally be acquired from the air.
[link to www.grouprecipes.com
The point is that as self-reliant people, we want to find natural sources to harvest from, and by doing so acquire yeast to use for baking, making wine, making vinegar, etc.
Raisin and persimmon and maple wine were the most common fermented beverages among the pioneers. The Apaches made Tizwin from corn but it was very tame. Of course apple jack was made from pressed apples made into cider which shortly thereafter "turned" or fermented into apple jack. Letting it go longer will produce vinegar. Since all of that is useful, we end up with something we can use at each stage, and finally for pickling and extending the harvest.