In our 18th Century cooking episode on “Which Yeast” we mentioned several instances of wild yeast cultivation in the late 18th century. Here is one dating from 1800. Notice that the author needs to explain this process as if it were not already known to the readers and it origin is Persia.
The preservation of yeast having been a subject of much research in this country the following particulars may perhaps deserve attention. On the coast of Persia my bread was made in the English manner of good wheat flour and with the yeast generally used there. It is thus prepared take a small tea cup or wine glass full of bruised or split peas pour on it a pint of boiling water and set the whole in a vessel all night on the hearth or any other warm place the water will have a froth on the top next morning and will be good yeast. In this cold climate especially in a cold season it should stand longer to ferment perhaps twenty four or forty eight hours. The above quantity made me as much bread as two sixpenny loaves the quality of which was very good and light
from the “ANNALS of AGRICULTURE and OTHER USEFUL ARTS”, 1800
Here is the complete text of the reference I mentioned in the video. As you can see from the text. Most of the western Europeans thought that the bubbling action on the yeast has something to do with fire, or heat.
From the Eighth Volume of the Transactions of the Society for the Encouragement of Arts Manufactures and Commerce. 1790