A growing number of breakfast institutions are offering an endless supply of prosecco, mimosas and champagne to the hung-over and the hungry, proving big thirsts are big business in the brunch trade.

Cafes hold a strong grip on Australians. “Latte sippers” became a political sledge in the ’90s, then there was the smashed avo debate of 2016 when buying brunch was labelled a reckless move if you ...