Sourdough Brownies

This recipe uses some of that discarded sourdough starter you’ve been saving up. These are a bit more “cakey” than straight up fudge bombs, since we are adding flour. I haven’t let the mixture sit to rise when making, but it’s possible the lighter texture is related to the rise of the sourdough during baking.

Sourdough Brownies
Prep time
Fermentation time
Total time
  • 141 grams (5 oz.) sourdough starter, 100% hydration
  • 227 grams (8 oz. or 2 sticks) pastured butter, melted
  • 200 grams (7 oz.) cane sugar
  • 170 grams (6 oz.) brown sugar
  • 125 grams (4½ oz.) cocoa powder
  • 4 pasture-raised eggs
  • 10 ml (2 tsp.) vanilla extract OR 7 cm (3 inch) piece of vanilla bean
  • 3 ml (1/2 tsp.) sea salt
  • (Optional) 75 grams (~3 oz.) soaked nuts
  1. Preheat oven to 300 F/150 C.
  2. In an 8-inch square baking pan, cut an 8" x 12" piece of parchment paper to fit inside the pan, leaving enough to hang over two sides of the pan (to create a sling). Grease the two sides of the pan that are not covered by parchment paper.
  3. Separate 2 of the eggs from their yolks (use whites for another purpose).
  4. Melt butter.
  5. If using vanilla bean, split lengthwise and scrape the seeds of the bean out. Add scrapings to butter.
  6. Beat the 2 eggs and 2 yolks with a mixer on medium speed until fluffy and light yellow, 2 to 3 minutes. Mix in sourdough starter.
  7. In a separate bowl, combine sugars, cocoa powder and salt. Drop mixer speed to low and slowly introduce the sugar mixture, about ⅓ at a time.
  8. Add butter and vanilla extract (if using) to bowl. Continue mixing batter. It will be ready when it's shiny with just small lumps.
  9. Pour batter into the pan and bake 45 to 50 minutes.
  10. Use a toothpick in center of pan. When it comes out dry (no crumbs), remove pan from oven.
  11. Let cool in the pan for 3 minutes, then lift brownies out using the parchment paper sling.
  12. Cut into 16 pieces (ideally with a pizza cutter) and let cool completely.


Inspired by Alton Brown’s Cocoa Brownie recipe, with a few tweaks to incorporate the starter, and a complete lack of respect for “Dutch process” cocoa vs. non.

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