Great idea! I would have used ambient light instead of a flash. The beer bottle is smudgy and I think you should have either taken the bottle lying on it's side out or centered it so that it was in the frame.
As a homebrewer the subject is obviously of interest to me but the photo itself I find lacking.
I think this would have been better on a light background instead of dark. The glare from the flash on the glass and bottles is troubling. I think if you cleaned the glass so it didn't look so dirty and used multiple well diffused lights set to the sides and back rather than the front you'd get a better shot.
I would also change the backdrop material and placement. Right now the ripples in the fabric draw attention and because subject is so close to the background you get some really harsh shadows. Moving them forward several feet at least will lessen the shadows. Then using proper lighting you can eliminate them all together.
You may also want to consider spreading out the grains at the base. Having a few extra grains sprinkled around might look a little more natural.
Looking at the photography in beer ads and magazines like BYO and Zymurgy (which you probably already have) will give great hints as to how to light this sort of scene.
This is a great idea for this challenge. Lighting though is a little bit harsh and the cropping is a little bit off especially the bottle down was cut off while there's ample space on the right of the standing bottle. I think a centered composition may have worked here. But I tell you, your did well in constructing this idea.