Dictionary:

frothy

  (frô'thē, frŏth'ē)

1. Made of, covered with, or resembling froth; foamy.
2. Playfully frivolous in character or content: a frothy French farce.

A descriptive cooking term referring to mixtures that are foamy, having a formation of tiny, light bubbles.

adjective

1. Consisting of or resembling foam: foamy, lathery, spumous, spumy, sudsy, yeasty. See solid/liquid/consistency.
2. Amusing but essentially empty and frivolous: light². See surface/depth.
3. Given to lighthearted silliness: empty-headed, featherbrained, flighty, frivolous, giddy, harebrained, lighthearted, scatterbrained, silly. Informal gaga. Slang birdbrained, dizzy. See ability/inability.

Definition: bubbly
Antonyms: flat

The adjective has 2 meanings:

Meaning #1: emitting or filled with bubbles as from carbonation or fermentation
  Synonyms: bubbling, bubbly, foaming, foamy, effervescing

Meaning #2: relating to or containing gas bubbles
  Synonym: foamy