Five years ago, after living in Northern California for fifteen years, I moved back to the East Coast. Soon I began to long for the soul-satisfying tang of San Francisco sourdough bread. Unable to locate a good source for truly sour and crusty loaves, I decided to make it myself. Two hundred batches later, I’m happy to report that I’ve developed a recipe to make world-class sourdough breads at home.
I’d heard that sourdough starters are fickle and fussy in comparison with commercial yeast. There is some truth to this rumor. Before you can produce consistently good sourdough bread, you need to get acquainted with a starter and to discover how often it needs to be fed, how long it takes to make dough rise, and what flavor it gives to the bread. Once you’ve figured out your starter, though, it will give you bread with wonderful, haunting flavors and a remarkably flexible bread-making schedule. Since sourdough breads have long rising times, I can mix the dough at night, form it into loaves the next morning, and bake the bread that evening after work. I’ve made the schedule even more flexible by using two complementary starters-one for muscle to make the dough rise and one to give the bread tang.
Finding a good starter
A sourdough starter is a batter that contains wild strains of yeast and lactobacilli bacteria. Wild yeasts work more slowly than commercially produced yeasts, and the leisurely rising time allows intriguing flavors to develop in the bread. The lactobacilli bacteria produce acids that give sourdough bread its legendary tang. Wild yeasts feed on starches and sugars and produce the carbon dioxide that makes bread rise. Yeasts produce the greatest amount of carbon dioxide right after they’ve been fed, then less and less until they’ve exhausted their food supply. Lactobacilli digest the same meal and give off acids. They slowly produce more and more acid, making the starter tangier the longer it sits. This means that a starter has the most vigor to make dough rise right after it’s been fed, but not much tang. As it sits, it loses its rising ability but develops a more sour flavor.
You can create sourdough starters by luring wild yeasts and lactobacilli to a good meal. In a glass or ceramic bowl, mix two cups of flour with two cups of either warm water, yogurt, milk, or the water that potatoes have been cooked in. Cover the bowl with a clean dishtowel or cheesecloth and let it sit in a warm spot for three to four days, stirring it once a day. If it bubbles and has a pleasant, sour smell, you have successfully attracted airborne yeasts and friendly bacteria. You then feed this culture a mixture of flour and water or thinned mashed potatoes until you have enough active starter to work with. If instead the starter turns moldy or has a peculiar smell, discard it and try again.
The two problems with making a starter are that your kitchen may not have enough airborne yeasts to colonize the bait, and if the flour mixture does attract wild yeasts, there’s no guarantee that the cap tured microorganisms will make the dough rise well or give the bread a pleasant taste. In the beginning, I made a couple of these starters from scratch, but they didn’t give the bread the flavor or the texture I was looking for.
Next I sought out proven cultures, which you can beg or buy. A friend gave me part of her starter, which had been fed on mashed potatoes. The very first loaf I made with it was a beauty: it rose perfectly and had a dandy brown crust. The potato in the starter made the texture spectacularly moist and chewy. The only flaw was that the flavor wasn’t the least bit sour.
A s nice as the potato starter was, it was only scratching half my itch. I needed that sourdough tang. That’s when I turned to dried cultures made with Lactobacillus sanfrancisco, the bacteria unique to the Bay Area that gives San Francisco sourdough bread its characteristic flavor. Although the starter gave all the tang I was looking for, I couldn’t coax it to produce anything but hard, crumbly bricks. I liked the taste of the bread it made too much to abandon the starter, so I worked to enhance its rising ability.
After dozens of tests, I solved the problem by combining the potato starter with the San Francisco starter when I mixed the dough. The robust potato culture made the loaves light, while the flavorful but wimpy San Francisco culture gave the bread its proper tang.
At first I was skeptical about using two starters. Maintaining them both was more work, and keeping two took more space in the refrigerator. By using them together, however, I’ve sidestepped the problem of catching a starter when it still has enough vigor to make the bread rise and has become sour enough for my taste. Hundreds of tasty loaves later, I wouldn’t think of making sourdough any other way.
Maintaining and priming the starters
The San Francisco culture needs at least 48 hours at room temperature after feeding to develop sufficient tang. Once the starter is sour enough, I make bread with some of it and put the rest in the refrigerator to use later in the week. The cold temperature of the refrigerator slows the metabolism of the yeast and bacteria, preventing the starter from getting too sour.
I feed the potato starter every two weeks. The meal is boiled Idaho potatoes, water, and sugar, mixed quickly in a blender to the consistency and sweetness of a milk shake. The potato starter often doubles in volume while it eats, and stays active and bubbly for at least 24 hours. When it stops bubbling, I put it back in the refrigerator.
Dough (and why I don’t use a sponge)
Unlike other sourdough bakers, I seldom make bread within 24 hours of feeding my starters, and I don’t make a sponge. I wait two or three days until the starters settle down so that the dough will rise slowly overnight. Many breadmakers first make a sponge before they mix the dough. A sponge is a soupy mixture of starter and flour that rises for several hours, allowing the yeast to multiply and the flour to ferment and develop more flavor. I don’t bother making a sponge because I put a lot of yeasty, flavorful starter in the dough. Also, the long rising time characteristic of sourdoughs allows complex, intriguing flavors to develop without taking the time to make a sponge.
Although San Francisco sourdough is traditionally made with just flour, water, culture, and salt, I didn’t have much luck using the classic formula with my starter. The bread was stiff and crumbly. By using the mashed potatoes in the potato starter, I improved the color and texture of the crust and made the interior moist. A scant tablespoon of olive or safflower oil per loaf makes the interior of the bread more springy and gives the crust better color. Milk powder contributes to the formation of a darker crust and makes a subtle but wonderful taste improvement: it helps create the lingering sweet flavors that you taste after the tang.
This bread tastes wonderful when made with white flour or part whole-wheat flour. I’ve had excellent results using flour made from an ancient type of wheat called spelt, which is less bitter than regular whole -wheat flour.
Making the bread
I like bread with a really crunchy crust and chewy crumb. The perfect loaf has a bottom crust that’s the color of bittersweet chocolate and a top crust that’s a little lighter. I bake on a clay pizza stone to get the dark bottom crust and put steam in the oven to ensure a
crisp top. I preheat the pizza stone on the bottom of the oven for 45 minutes at 500°F. Five minutes prior to baking, I take the stone off the floor, put it on the bottom shelf, put a pizza pan on the bottom of the oven, and turn the heat down to 425°. Then I slide the loaves off the peel and onto the baking stone. As soon as the loaves are on the stone, I pour about a cup of water into the pizza pan and quickly shut the door so the steam doesn’t escape. I bake the loaves until the crust is very dark, from 50 minutes to an hour.
Cooling and storing
Sourdough bread freezes well. As soon as a loaf has cooled completely, If I’m not going to use it right away, I put it in a resealable plastic bag and toss it in the freezer. The bread emerges, after a 2-hour thaw, virtually the same as fresh. At room temperature,
the aging process quickly robs sourdough bread of its textural charm. Take heart, though: you can banish the curse of flabby crust and cardboard crumb. Keep a plant mister near the toaster and spray stale slices before toasting. With practice you can recreate the exact moistness of the original loaf.