Milk Yeast

Considered the “instant” yeast of colonial times, milk yeast was easier to make than the others, but it was also the most unsafe because there were no hops to selectively destroy wild yeasts and bacteria. Country bakers did not know what bacteria were, but through trial and error they were well acquainted with the end results, both good and bad.

To make milk yeast, raw milk was mixed with salt and coarse flour or cornmeal and put in a warm place to ferment. Naturally occurring yeasts in the flour or cornmeal gradually produced enough of a yeast culture to create a foamy liquid. This was often incorrectly called salt-rising yeast on the mistaken assumption that it was the salt that caused the reaction. Once the milk and flour mixture began to foam, it had to be used immediately or it would lose its strength and sour.