Who would ever think of making soap using beer in place of water? I would, of course, and several other soapmakers that I know of. The trick is to let the beer go absolutely flat. I have used it as a shampoo bar for my hair.
I didn't use any colorant or fragrance because I wanted the true aroma to shine through. After curing there was a slight pleasant herb smell. I'm guessing maybe hops. I used Guinness and got this beautiful golden color but I'm sure any beer can be used.