Rhinegeist

Rhinegeist Brewing is a beer that I've seen multiple times in stores and was interested in trying.

They do make beers with cocoa, coffee, fruit, and spices, so you should be careful about those depending on what your Rabbi says. They do not make any of the odd beers, but they do make a beer with lactose, honey, and fruit juices. They also age some beers in wine casks. They do not share anything with other breweries and while there is a pub in the same building, they are operated completely separately and do not share equipment.

The interesting thing about Rhinegeist that I am still looking into is that they do use champagne yeast in some of their beers (limited circumstances). Since it's made from grapes, that can be a kashrut concern. I am currently waiting on more information from the Star K and Rhinegeist themselves regarding this detail. I will update when I have more information.

Before we were aware of the champagne yeast, their unflavored beer fit the Star K standards. However, at this point in time, I'm not sure where it stands until I get more information.

Update: The champagne yeast is only used in some of their Outer Reaches program and is bottled carbonated with a cork and cage top, so they are obviously different. That makes it easy to tell which ones use the yeast and which don't. You should be able to have their unflavored beers, but ask you Rabbi.

Update part 2: According to the Star K and CRC, champagne yeast is not an issue.