Take three Pound of White-honey, or the best Hampshire-honey, and dissolve it in a Gallon of water, and then boil it; and when it beginneth first to boil;
put into it half a quarter of an Ounce of Ginger a little bruised; and a very little Cloves and Mace bruised, and a small quantity of Agrimony.
Let all this boil together a full hour, and keep it constantly skimmed, as long as any Scum will rise upon it.
Then strain it forth into some clean Kiver or other vessel, and let stand a cooling; and when it is cold, let it stand, till it be all creamed over with a blackish cream, and that it make a kind of hissing noise; then put it up into your vessel, and in two or three months time it will be fit to drink.

Look how much you intend to make, the same quantities must be allowed to every Gallon of water.

(From The Closet of... Sir Kenelme Digby... Opened, 1669. )

Note: in both these recipes no mention is made of the addition of yeast. In older houses, where brewing and baking have been done for many years under less than sterile conditions, yeasts have taken up residence, their spores swirling freely in the air and falling into vats and kneading troughs, raising the bread and fermenting the beer without human intervention.
It is possible that those recipes which leave out the yeast come from homes with such resident yeast colonies. Or, it may simply have been an oversight.