Many people have taken up baking as they’re sheltering in place. If you want to join that trend, KCRW’s Evan Kleiman gives some tips.
Starting your sourdough starter:
There are a few different methods for imploring the yeast in your kitchen and those in the flour to converge and begin replicating themselves. But all of them need the same basic ingredients: oxygen, water, carbs and time.
I prefer to mix equal parts (by weight) bread flour and water in a glass jar, so that it takes up just a third of the container (about 100g of each for a medium-sized jar). If you only have all purpose flour in the house, that is fine. Cover, leave in a warm spot overnight, and return to it 24 hours later. You should see a little bit of bubbling action through the jar. If you don't, leave it out another 12-24 hours.
Once you see a little bubbling, remove half of what's in the jar, and feed it another 100g or so of water and flour. If you're in a hurry for this to happen, add a pinch of rye flour. Cover, go about your business, and return to it a day later. Repeat this process for a few more days. Once you begin to see a pattern of behavior, watching it rise up 5-6 hours after feeding and crashing back down, you've successfully gone from creating a culture to a working, active starter.