Rēwena parāoa is a traditional Māori sourdough bread leavened with a fermented starter made from boiled, mashed potatoes and flour, locally termed the 'bug'. The high starch content of the potato provides readily available sugars for wild yeast and lactic acid bacteria, yielding a dense crumb with a distinctive sweet-and-sour profile, showcasing an ingenious adaptation of colonial staples into indigenous baking.