Bring to a bubble

BOIL

Think of what happens when water reaches 212°F and starts producing steam.

"Bring to a bubble" is a straightforward definition for "boil," since boiling a liquid causes bubbles to form. The clue plays on the literal meaning—when you heat water or another liquid, it reaches a boiling point and starts bubbling. There’s no hidden wordplay here, just a direct connection between the action (boiling) and its visible effect (bubbles).