This might be "The Beautiful Brew" (1954) by James E. Gunn. First published in Beyond Fantasy Fiction, September 1954.
It was the essence of beer captured in a glass. The hucksters, for once, couldn’t possibly oversell it. The clear, pale yellow had a sparkling brilliance; tiny bubbles streamed delicately to the top.
Something had piled the foam high in the center of the schooner and sculptured it into the shape of a girl. She began at the waist, a perfect, three-inch replica, her arms raised, her hands smoothing long, foam hair.
This time a foam hand seemed to reach out to meet his hand. He jerked it back. The foam came with him; the girl came with the foam, stepped out of the yellow pool as if she had legs, standing on the pavement as if she had feet. Her creamy chest rose and fell. Her eyes opened. They were deep blue, like a summer sky mirrored in a mountain pool.
You can read the entire story at the Internet Archive.