If you’re an apartment-bound urbanite with nary a backyard to plant, here’s a micro-farming solution acceptable for even the smallest spaces: Grow yourself a sourdough starter, also known as a levain.

“It’s a little like farming,” said Austin Hall, the head baker at She Wolf Bakery. “You’re trying to grow this organism that is going to help you raise the bread.”

So if you’re not cleaning out your kitchen this weekend in preparation for Passover, consider combining some good flour with water, and then letting it sit in a cool spot for a two days. There’s yeast naturally present on the flour, and it just needs nurturing.

“What you’re trying to do is cultivate a colony of yeast and bacteria,” Hall said. “It doesn’t sound very appetizing but, trust me [it is].”

Since there are only two ingredients that go into making a starter, pay attention to each. First of all, don’t use white flour. Instead, choose a whole wheat or whole rye flour. She Wolf Bakery, which supplies restaurants including Roman’s and Marlow and Sons, gets some of its flour from local purveyors at the Union Square Farmers Market.

“All those nutritious things that are good for humans are also good for tiny bacteria,” Hall said. “In about two days, you can get the very beginning of a culture. If you’re starting from nothing, it takes probably a week before… you’ll have a strong enough culture that you can actually bake a loaf of bread from it.”

(Photo: Austin Hall/Courtesy of She Wolf Bakery)

Ingredient number two for a sourdough starter is water. Hall explained that New York City’s tap water is chlorinated, so it’ll kill microorganisms unless the chlorine is allowed to evaporate.

“It’s most important when you’re very first starting out to use either distilled, bottled water,” he explained, “or you can take regular tap water and let it sit on the counter for 8 to 12 hours, and all that chlorine will off gas and you can mix dough with it.”

Finally, add a healthy dash of patience. Nothing will happen to the flour and water mixture in the first 24 hours. Even after it begins to double in size, there’s still a few more weeks of tending to do.

“Don’t get discouraged in the beginning if it doesn’t taste like sourdough,” Hall said. “It’s far easier to cultivate the yeast colony than it is to cultivate the bacterial colony. It takes probably three weeks of regular of feeding before you’ll get enough of a bacterial colony for it to really taste like sourdough bread.”

If all this sounds more like the unnecessary hassle of tending a Tamagotchi pet, rather than watching the fascinating activities of an ant farm, there’s another option. Cozy up to a baker and ask for a piece of starter. Keep it alive by regular feedings, and, boom, you’re ready to go.

On the other hand, if you’re ready to get yeast farming, check out Hall’s directions for creating a sourdough starter.