Sourdough is really bread that has been leavened with starter (natural yeast), rather than with commercial yeast. It is delicious, has some terroir and if you like sour dough (or not!) you can control the sourness by how often you feed it. I use a desem starter. The desem culture originated in Belgium, as the Belgian answer to the French pain au levain (aka French not-so-sourdough). It is meant to be fed whole wheat flour and eventually, to make whole wheat bread.
I’ve had mine for almost 3 years now, though I did accidentally use it all up one time. I don’t count that because I’d given some to a friend beforehand, and she gave some back to me after his death, so I like to think of that as my culture going off to get a little culture, then coming back home.
Personally, my favorite way to start starter is to get some from a friend. I love that the bread you bake will have a sense of history and community, and a little bit of the character of your friend’s home, too. It’s really easy to make your own if you don’t have a friend with starter. Here’s a great tutorial from Serious Eats. If you live in Philly, I’m happy to share mine since I ALWAYS have extra.
The key to sourdough is regular feedings. I think of mine as a pet so I feel bad when I don’t feed him. Also, since he’s Belgian, I call him Hercule. Get it?!
I use my iPhone reminders feature for all of my ferments, otherwise people (okay, ferments) die. And it feels horrible, like when you kill a plant you grew from seed. An established starter should be fed at least weekly, and refrigerated between feedings. If you keep your starter on the counter, it should be fed daily. In the summer heat, I could stand to feed him twice a day, but he generally gets by on one. The only reason to keep your starter out is to have it ready to use. If you’re not baking bread everyday, by all means, keep it in the fridge except for those essential weekly feedings.
Take a small amount of starter. I like to go by weight, but you can also do volume, no problem, at this stage. I take 20 g (you could do a tablespoon, say) of starter, add 20 g whole wheat flour 20 g all-purpose flour and 40 g of lukewarm water. Stir vigorously until well-combined. Cover with a cloth, secure that with a rubber band and set aside to ferment at room temperature for 24 hours. Obviously if you’re about to bake a big loaf of bread or make multiple pizza doughs, you’ll want to reserve a larger amount of starter to feed so you end up with enough finished product for your recipe.
If you’re not baking regularly, there’s no need to feed your starter everyday. You can simply stick it in the fridge for up to 7 days before feeding it again. When you’re ready to bake with it, pull it from the fridge and feed it for a couple days to get it active before you start baking.
There are many ways to use that extra starter that inevitably starts to pile up. Here’s a link to my favorite way to use that extra starter so you don’t need to trash it. Extra starter will store fine in the fridge for a week or more, but it does get increasingly sour the longer it’s there.
Once you have a good amount of starter bubbling, you can make delicious things, like bread!