I recommend shredding your cheese for these crackers if you want a consistent texture, but you can use pre-shredded if you're in a pinch.
2 (220g) cups freshly shredded sharp cheddar cheese
Make sure your butter is cold before you continue to the next step. Cut your butter into small 1/4 inch cubes.
¼ (57g) cup unsalted butter
In a food processor fitted with the blade attachment or a blender, add the shredded cheddar and the butter cubes.
Add the flour, cornstarch, sea salt, white sugar, garlic powder, onion powder and baking powder to the food processor or blender.
1 (120g) cup all-purpose flour, 1 teaspoon cornstarch, ¾ teaspoon fine sea salt, ½ teaspoon garlic powder, ¼ teaspoon onion powder, 1 teaspoon granulated sugar, ⅛ teaspoon baking powder
Pulse the ingredients until the cheddar and butter are cut into small bits and well coated in the flour mixture.
Add the sourdough discard (remember cold discard is best). Pulse until the dough starts clumping. If it’s too dry, add ice water 1 teaspoon at a time until it just comes together.
¼ (60g) cup cold sourdough discard (100% hydration)
Sourdough Discard Swap: If you want to skip the discard, simply add additional ice water until the cracker dough comes together.
Be very careful when adding water not to add to much, you want dough to barely form a ball. Avoid overmixing the dough at this stage or the crackers will get tough!
1-2 Tbsp ice water
Divide the cracker dough into two sections, and wrap tightly with plastic wrap pressing gently to form a disc. Refrigerate the dough at least 2 hours to chill before proceeding with cutting out the crackers.
Optional Overnight Fermentation: If you want additional fermentation time for the sourdough starter to really work on breaking down the gluten in the dough, refrigerate the dough overnight.