Where does “fermentandus” come from?

fermentandus (Latin) comes from Latin fermento, from Latin fermentum, from Latin ferveō, from Proto-Italic ferweō, from Proto-Indo-European bʰrewh₁-, from Proto-Indo-European bʰer- — to bear, carry.

Definitions

Ancestry of “fermentandus”, step by step

Step	Language	Word	Meaning
1	Latin	fermento	I cause to rise, ferment or leaven; I cause to...
2	Latin	fermentum	fermentation, leavening; yeast, ferment; anger,...
3	Latin	ferveō	to be hot
4	Proto-Italic	ferweō	—
5	Proto-Indo-European	bʰrewh₁-	to boil; to brew
6	Proto-Indo-European	bʰer-	to bear, carry

Every word from Proto-Indo-European bʰer- →Every word from Proto-Indo-European bʰrewh₁- →Every word from Proto-Italic ferweō →