Coffee purist footing delicate brews (4,5)

I believe the answer is:

iced latte

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

'footing delicate brews' is the definition.
I know nothing about this answer so I cannot judge whether this works.

'coffee purist' is the wordplay.
'coffee' becomes 'iced coffee' (iced coffee is a kind of coffee).
'purist' becomes 'latte' (I can't explain this - if you can you should give a lot more credence to this answer).
'iced'+'latte'='ICED LATTE'

Can you help me to learn more?

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

Want a hint initially instead of a full solution? Install my app