The setting is that of a world with a technological level around the Interwar Period and a societal level around that of the Victorian Era.
Though answers to this question are encouraged to go further back to Medieval times and farther.
That said, this question is about the decision of a larger region or country granting the local clerical body the exclusive right of the production of alcohol & alcoholic beverage, as well as the right of granting brewing/distilling permits to third parties.
The church does not control import/export of alcohol & alcoholic beverages, but they decide who they supply with their own products and who not.
Thus they effectively control the supply of alcohol in the whole region/country and thus the festiveness of tens-of-thousands of people1.
Q: Why would they be granted such an exclusive right/permission?
I have thought about them in turn having to provide certain amenities or similar, e.g. hospitals, almshouses and orphanages. Certainly these services and their provision would have grown over time with the cultural connection of church and wellfare as well.
But would that be a big enough burden to offset that huge boon of controlling a major commodity?
1Again, excluding imports from other regions/countries..
Addendum: The church itself is a rather huge polytheistic confluence of older simpler polytheistic and monotheistic religions of different areas and tribes.
They started off as the spiritual part of herdsmen and nomads of the Green Wides. Due to the nature of the people of these areas, the original churchmen started creating fix settlements where the wandering groups would find shelter, could exchange wares and bury their dead without fearing bandit raids or similar.
Over time the wandering groups would strife further north, west, south & east and thus get in touch with other groups and religions, which they understood to integrate into their own pantheon in order to mingle with these others.2
2Others that soon became part of their growing culture & society.
Anotherdendum: As many seem to still automagically assume Church to refer to a monotheistic organization based on a set of two books that in turn are made up of dubiously sourced letters and other short texts - here's a definition:
- claim universality, include all members of the society within their ranks, and have a strong tendency to equate 'citizenship' with 'membership
- exercise religious monopoly and try to eliminate religious competition very closely allied with the state and secular powers - frequently there is overlapping of responsibilities and much mutual reinforcement
- extensively organized as a hierarchical bureaucratic institution with a complex division of labor
- employ professional, full-time clergy who possess the appropriate credentials of education and formal ordination
- almost by definition gain new members through natural reproduction and the socialization of children into the ranks
- allow for diversity by creating different groups within the church (e.g., orders of nuns or monks) rather than through the formation of new religions