Sourdough Rye Crackers With Coriander and Fennel Recipe

In a large bowl, whisk all-purpose flour, rye flour, sugar, and salt until combined, about 60 seconds. Using a silicone spatula, stir in starter, champagne, and olive oil until mixture is smooth and combined, 1 to 2 minutes. Using clean hand, gently knead dough and form into round ball. Cover dough with plastic wrap and refrigerate for 30 minutes or up to 2 days.

Adjust oven rack to middle position and heat oven to 325°F (160°C). Remove dough from refrigerator. Divide dough into 3 equal portions. Working with one portion of dough at a time (keep other portions in the refrigerator), place dough between 2 sheets of parchment paper sized to fit rimmed half-sheet pan. Using rolling pin, roll dough until it fills dimensions of parchment and measures roughly less than 1/16th inch (1.5mm) in thickness.

Slide parchment with rolled dough onto rimmed half-sheet pan. Gently peel off top layer of parchment and reserve as bottom parchment layer of next batch. Sprinkle dough with coriander, fennel seeds, and flaky salt. Bake until deep golden brown and uniform in color, 16 to 20 minutes, rotating baking sheet halfway through baking. Let cool until crisp and no longer hot to touch. Gently peel off cracker sheet from parchment and break into large pieces. Discard used parchment.

Repeat rolling and baking with remaining two portions of dough and additional parchment paper as needed. Crackers can be stored in airtight container at room temperature for up to 5 days.