He cultivated the yeast for a week using unfiltered olive oil, hand-milled barley and einkorn, one of the earliest forms of wheat, until he had a starter, like that used to make sourdough bread.
This is so dumb. It’s highly likely the yeast he actually cultivated was the active yeast living already on the barley, the olive oil or in the air. This is literally all you need to do to make sourdough starter, no innoculation necessary.
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