Here’s how it goes: Heat the oven to 350° F. In a medium bowl, use your fingers to whisk together a fat pinch of kosher salt and about 1 cup flour. I like to use a mixture of whole wheat and all-purpose, but whatever you have on hand will work. I’ve even made them with half chickpea or buckwheat flour.
Pour in about 1 cup sourdough starter discard and about ¼ cup olive oil and combine until the dough comes together. At first, it’ll be shaggy, but it will become increasingly taut. Knead a couple times to make sure everything is combined and the dough forms a smooth ball. Divide into thirds.
Lay a piece of parchment paper on a work surface and roll out one ball of dough into as big and thin a sheet as you can without tearing it. Dimensions don't really matter here: as long as it’ll fit on a sheet pan, it’s perfect. Transfer the parchment to the pan, then brush the surface of the dough with a bit more olive oil. If you have more sheet pans, you can prepare all three cracker sheets at once, or you can bake in shifts.
Now, toppings. Usually all I want is a shower of flaky salt, but anything goes.
Za’atar, sumac, garlic powder,
nutritional yeast. For slightly heavier seasonings, like fennel, cumin, poppy, or sesame seeds, or dried herbs, brush the surface of the dough with a beaten egg white instead of oil, then scatter the topping and press them in gently, or knead them directly into the dough before rolling it out. You can also go sweet—cinnamon and sugar is a delight. This is the time to experiment; there are no wrong answers (she says, as she eats a bite of a cracker topped with nooch and
turbinado sugar, which tastes like when you mix a handful of cheese popcorn with caramel corn from those giant holiday tubs).
Slide the tray into the oven and bake for 15–20 minutes, until the giant cracker is golden brown. Let it cool completely, then snap it into jagged pieces. Store the crackers in an airtight container at room temperature, and grab a couple every time you walk through the kitchen. Maintaining a sourdough starter can be maddening, and producing an intricately scored, crusty loaf of bread is a days-long, painstaking process. So even if you’d rather opt for purchasing sourdough made by an expert, hang onto that starter and you’ll never need to buy another box of crackers.
