Costco's New Sourdough Bread Ignites 50-Ingredient Authenticity Debate

1 articles · Updated · Fox News · Jul 28

Costco shoppers are split over the new Kirkland Signature olive and rosemary sourdough loaf, with critics arguing the product should not be marketed as true sourdough.
Real Bread Campaign says genuine sourdough should rely on a live starter alone, without commercial yeast or additives; commenters said Costco's loaf includes yeast, yeast extract and roughly 50 ingredients.
Instagram helped drive both the hype and the backlash after @costcohotfinds, which has 3.5 million followers, praised the bread's olives, crust and chewy center.
Many buyers still said the loaf is worth purchasing despite the label dispute, while some purists urged shoppers to support local micro-bakeries instead.
The argument echoes a similar reaction earlier in 2026 to Costco's sourdough bread bowls, underscoring recurring skepticism about store-bought 'sourdough' made for commercial speed.