The recipe is from the 1880s.
I find it interesting that the yeast from the hops will survive boiling ("simmering) water temperatures... Part of the reason for boiling is to kill other, undesirable, bacteria and molds from growing in the yeast medium.
https://survivalblog.com/recipe-week-yeast-mama-b/Since few of us will have hops in our spice cabinet, I would recommend that you experiment with other kinds of leaves. For instance; blackberry leaves and fruit, potato skins
I'll point out that this recipe will produce usable yeast in only 24 hours. Contrast this to the week or more needed to start a sourdough yeast starter.
NOTE: no mention is made of keeping this yeast culture alive by regular feeding of more flour. This may have been common knowledge to our grand parents...