So, from start to oven, here's the basics on whole wheat, sourdough crackers.
I keep my starter in a small plastic dish, with a lid, in the fridge, for about a week. When I pull it out, it looks like this:
I weigh it, and then double that weight with 50% water, 50% whole wheat flour. So, just to follow the photo - the plastic dish is 25g, so I have 250g of starter. therefore, I add 125g of water, 125g of flour.
I move the whole lot to a bigger container, one of those designed for baking, also with a lid, and stir it up. Sometimes I let my daughter stir it for 20 minutes. doesn't help, doesn't hurt:
Then let it sit. Most sources say 'feed it' every 8-12 hours. I've gone 24 without any ramifications. However, this is where you have to start thinking and planning about how much you'll use during this round of baking, how much you want to have left over, and how much you might figure out how to use quickly - like by making pancakes or something. Every 8 to 24 hours, you're going to have about twice as much as before.
Now, you don't *have* to completely double it every feeding. I've gotten away with just adding 'some', especially when I'm getting close to having too much. Still, it IS important to always keep the water/flour weight ratio exact.
When you're feeding or ready to add it into the baking process, it should look 'active'; bubbled up, not exactly doubled, but bigger for sure. When you stir it, I think what makes it seem 'healthy' is the strands between the bubbles. You can just see a bit of that at about 11 o'clock in this photo of my bowl. As you stir it up, the bubbles of course go away.
Moving on to the cracker specifics. First, remember to always set aside a little bit to store for next week. Then, the way I make crackers is always vague in measuring, because you never know exactly how much starter you're dealing with - that is, the amount is different every week. So:
to the bowl of starter, I add:
about 2 tablespoons of olive oil for every cup of starter. a bit more won't hurt
a teaspoon of salt for every cup of starter,
2 tablespoons of sesame seeds for every cup of starter,
and then I start adding a bit of flour (maybe 1/2 cup at a time) stirring until it turns into dough:
As it gets to hard to stir with a spoon, I dump it out on the counter and keep adding flour and kneading until I get a nice smooth, soft ball that looks and acts like pizza dough you see in the cartoons.
Then, once I have it shaped into a nice ball, into a rising bowl that's coated in oil until the oven is ready to bake - somewhere between 2 and 5 hours.
Then grab a piece off, spread it on a floured surface, roll out with rolling pin until it's *quite* thin, then I spread an extra sprinkle of BIG sea salt, roll that in, cross cut with pizza cutter, transfer to baking sheets and toss in the oven for a few minutes until brown. Done.