Step 1

Preheat oven to 350F/180C.

Step 2

Add sourdough discard, flour, soft butter, salt and parmesan to a mixing bowl and bring the ingredients together to form a pliable dough (see notes).

Step 3

Divide the dough into two portions (this makes it easier to roll).

Step 4

Place each ball onto a piece of parchment paper and flatten out with your hands into a rough rectangle.

Step 5

Sprinkle on the rosemary and push it into the dough gently.

Step 6

Now roll out to a thin sheet of dough using a rolling pin. You want it around 1/16" or 1.5mm thick. The thinner you can get it the better because thick crackers won't cook properly and won't crisp up in the oven.The dough should not be sticky at all and easy to roll - however see notes below for some troubleshooting if your dough is sticky.

Step 7

Use a cracker roller to perforate dough. If you don't have a cracker roller you can use a cookie cutter or knife to cut into crackers and then pierce each one with the tines of a fork.

Step 8

Place each parchment paper with dough on top onto a baking sheet. This recipe will generally need two baking trays.

Step 9

Brush dough with olive oil and sprinkle with salt.

Step 10

Bake at 350F/180C for around 25 minutes or until crackers are golden and crisp.

Step 11

Let the crackers cool on a rack before breaking into individual pieces.