I'm a homebrewer and general beer nerd so needless the say I would really like to be able to brew beer in this game. I remember the beermaking skill in legacy and though it was cool despite only being able to brew Weißbier. The process in legacy game was pretty close to how it's done in real life, no complaints there. In the current game, you can grow barley,wheat, and hops, so the next logically conclusion is to bring back the ability to brew beer. Not only that, but since barley (The primary grain for beer) is now available, why not have a variety of styles of beer instead of just one?
The beauty of beer is that there are so many different kinds. Why not take advantage of this by having mutliple recipes to brew different styles, with different effects? Having multiple styles of beer to brew would truly make the Beermaking skill super rewarding, and if done right, beer can be crucial for players who want to take full advantage of FEP bonuses and perhaps other kinds of buffs.
Weißbier can definitely still have a place in the beermaking skill (Though I think is should be 50/50 Wheat and barley grist, not 100% wheat, for the sake of accuracy), but I'd like to throw out some ideas of how other beers can be made.
IPA/Pale Ale: All barley grist with a higher than average amount of hops.
Brown ale: Add the ability to kiln malt a second time to create brown malt to add to a barley grist
Stout/porter: Kiln malted barley a third time to create Roasted Barley malt to add to a barley grist.
Saison: Barley grist with some wheat added.
Braggot: Barley grist with a generous addition of honey to the wort.
Fruit beers: Barley or wheat grist with different fruits added. Lots of options with this alone.
Barleywine: Barley grist requiring more barley and a bigger hop edition.
Gruit: Replace hop addition with bog myrtle and/or juniper berries.
Ale/wine hybrid: Wort and grape juice added to barrel.
That's just what I came up with off the top of my head. I truly believe if something like this is implemented, it would attract all kinds of beer nerds like myself who long for a medieval brewery simulator.