Nidua (Fermented Spiderbone Alcohol)

Spiderbone juice, found within a spiderwolf's bones (note that this is separate from bone marrow, spiderbone juice is used in hydraulic systems), is a highly coveted ingredient. It's extremely nutrient rich and has a unique flavor that gives it a reputation as an extremely acquired taste. It is possible to ferment this liquid into a clear blue alcohol- nidua, often mixed with drops of spiderwolf venom and downed as a drinking game. The venom itself is extremely bitter, added more for bravado than flavor. The drink, on its own, has an intense fruity flavor, tasting like kiwi brandy (note that kiwis don't exist on the continent).
Nidua is a common offering in Eideli religious ceremonies.

Nidua Brewing

In smaller towns, the nidua brewer tends to be the holy man, so intertwined are the two roles.
However, when it comes to large cities and grand temples, the quantities of nidua required often cannot be produced on-site.

In Other Cultures

Spiderwolves are one of the most prolific carnivores throughout the continent, one variant or another existing everywhere in the mainland except the northernmost regions and eastern desert. As a result, spiderbone juice is a widespread phenomenon. As people can and will make alcohol out of everything, the concept of making spiderbone juice into alcohol is nowhere near exclusive to Eidel. However, Eidel by far places the most religious significance on the drink- nobody else literally has their gods' voices literally asking for the stuff, after all (even the rest of the greater pantheon).
Due to Eidel's massive influence and long-standing nature, spiderbone alcohol is generally referred to as nidua by other cultures as a loanword.