Beer that's right is frothier (7)

I believe the answer is:

sudsier

I'm a little stuck... Click here to teach me more about this clue!

'frothier' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'beer that's right' is the wordplay.
'beer' becomes 'suds' (synonyms).
'that's' becomes 'ie' (abbreviation for 'id est', 'that is' in Latin).
'right' becomes 'r' (abbreviation).
'suds'+'ie'+'r'='SUDSIER'

'is' acts as a link.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.