Honorable mentions:
Now, there are some tasty bubbles! That pint has a very nice head of foam indeed.
The essence of froth, well captured.
You can't quite see the bubbles, but you know it's foam... Nicely done long exposure.
3rd. place:
This shot has a dynamic feel to it. The color scheme works nicely and yes: the bubbles are there.
2nd place:
Very well framed and the slow exposure time creates a nice potpourri of sharpness and blur. B&W is perfect for this...
Winner:
These bubbles look like a moonrise on some foreign plant. I love the prismatic colors and the framing.