Sourdough is a yeast and bacteria colony growing in a flour and water matrix. The magic that makes it more than a flour-and-water paste are the microorganisms that hang out in the flour and in the air, waiting for the moment they can grow. The organisms are microscopic, of course, but their presence is abundantly obvious when activated by water. The flour provides food sources — complex carbohydrates and proteins — that break down to produce sugars, acetic acid, lactic acid, carbon dioxide and alcohol. Here's Wikipedia's simple explanation:
“Sourdough is a stable culture of lactic-acid bacteria and yeast in a mixture of flour and water. Broadly speaking, the yeast produces gas (carbon dioxide), which leavens the dough, and the lactic-acid bacteria produce lactic acid, which contributes flavor in the form of sourness. The lactic-acid bacteria metabolize sugars that the yeast cannot, while the yeast metabolizes the byproducts of lactic-acid fermentation. During sourdough fermentation, many cereal enzymes, particularly phytases, proteases and pentosanases, are activated through acidification and contribute to biochemical changes during sourdough fermentation.”
It's much, much more complicated than that, so check out the Wikipedia entry if you're interested in digging deeper.
Sourdough is nothing new. It's ancient. Wild fermentation of grains, what we call sourdough, started over 10,000 years ago with the origin of agriculture.
For thousands of years sourdoughs were the only leavening, and they were treasured and protected. Modern bread, made with consistent and uniform baker's yeast, dates from the 1870s. Dried granulated yeast, the kind that went so missing after the pandemic flurry of panic baking, was introduced after World War II. But we can do better without it. Wild yeasts and bacteria that you can capture yourself are everywhere, and they are much, much more flavorful, delicious and delightful.
Making your own sourdough starter is easy. It's just flour and water. But there are some important nuances.
You want a clean, glass one-quart jar with a non-metal lid. Starters need plenty of room because they expand, sometimes tripling in size. You need a lid that can be left loose so extra carbon dioxide can escape. A good wrap of plastic, secured with a rubber band, will do the trick.
1 cup water: If you are on city water, it's probably treated with mild anti-bacterials (like chlorine). In this case we want the bacteria to live, so use bottled or filtered water.
1 1/2 cups organic all-purpose flour (see note on rye flour, below):Standard commercial flour is bleached and bromated, and both processes kill naturally occurring microorganisms, so use the natural, organic stuff. I like to replace a couple of tablespoons with rye flour, it's a big booster. Look for it in natural food stores.
Mix the water and flour together in the glass jar. Cover lightly. Within hours the microscopic community starts working, and you'll start seeing bubbles. Stir twice daily. To build strength, feed it daily for three days by adding 1/2 cup of water and 3/4 cups of flour, then stir. If the jar gets too full, make some flatbread (recipe follows). After three days the mixture will start bubbling with life! It will be foaming out of the jar. (Make some more flatbread or cookies. Check out the recipes for sourdough discard.)
Keep the jar covered loosely so gases can escape. Careful! A tight lid will result in pressure buildup and a big mess when you finally let it all out, so watch out! At this stage someone doing the dishes might try to clean up your starter. Label it with warnings: “Live Active Starter, do not destroy!”
With daily feedings you'll have a good, going starter ready to use. By feeding daily you select for very active microbes that prefer a less acid environment. Now your starter can be used and “refreshed” regularly with a flour-to-water ratio of 1.5 to 1.
Sourdough starter is designed to be a source of leavening for continuous use. That's how it works best. It can be stored in the refrigerator for weeks. It will separate and turn brown, but you can revive it by pouring out most and refreshing every day until it revives. Really, if you were an ancient Jew in Egypt or a sourdough gold miner in Alaska, you would want to use it every single day. It's a commitment.
When you have too much starter to fit in the jar, you can use the “discard” for many things. For example:
1 heavy skillet (preferably cast iron)
1 teaspoon vegetable or olive oil
1/2 cup sourdough starter mixed with a pinch each of salt and baking soda
Optional: A sprinkle of powdered garlic, herbs, spices or chili powder Heat the skillet over medium heat. Add the oil. When a drop of water sizzles in the pan, pour your sourdough starter in like a pancake. Sprinkle with seasonings if used. Cook until bubbles form on the top side. Turn over and cook until browned. Eat!
I've got my starter, now what?
It’s time to use that active, bubbly, tangy anti-depressant starter for sourdough breads and anything else you bake — pancakes, biscuits, cookies, even sourdough chocolate cake. I'm feeling better, happier and younger already!
Northwest Sourdough, Teresa Greenway, is the gold standard for learning more: northwestsourdough.com
Sourdough Pancakes or Waffles by King Arthur Baking Company
Sourdough Chocolate Cake by King Arthur Baking Company
Sourdough Chocolate Chip Cookies by I AM Baker
I can see the old Klondike prospectors making biscuits this way, but they probably used bear grease instead of butter. Modern baking powder is an option if you don't want to wait for the biscuits to rise. A cast-iron skillet is a necessity for best results. (See “Molly's Method of Curing and Caring for Cast Iron.”) Makes 8
9-inch cast-iron skillet
1 cup organic all-purpose flour
1 cup organic white wheat or whole wheat pastry flour
1/2 teaspoon salt
1 tablespoon sugar
2 teaspoons baking powder (optional)
2 Tablespoons butter, melted
2 cups active sourdough starter (freshly fed 12 hours in advance)
Additional melted butter as needed
In a large bowl, mix flours, salt, sugar and baking powder (if using). Add butter and mix in. Form a hollow in the flour mixture and pour in 2 cups sourdough starter. Using a fork, slowly mix starter around until it has picked up all the flour. You should have a soft, sticky dough. Add a couple teaspoons of water if needed. Pinch off balls about the size of an egg (2 1/2 ounces each), flour them and pat into rounds 1/2 inch thick. Butter the skillet and fill with the rounds with edges touching. Brush with melted butter.
Baking powder is an optional convenience in this recipe, but it's been around since the 1840s. If you add the baking powder you can bake the biscuits right away. For authentic sourdough biscuits, cover lightly with plastic wrap and let rise for 2-1/2 hours.
Preheat oven to 425 degrees. Bake for 12-15 minutes, until lightly browned. Brush with melted butter. Let them cool a few minutes and then enjoy your hand-made, wildly fermented biscuits. Pass the butter and the peach preserves, please!
Whether a new pan or a rusty pan, the curing method is the same. If your pan is crusty from years of service, you can clean it by “burning” it in a fire or in the self-cleaning cycle of your oven. Then you have to cure it again like new.
1. Wash and dry pan completely, removing any rust.
2. Spray pan all over, front and back, with vegetable oil.
3. Using a paper towel, rub the oil into the pan, rubbing off any excess.
4. Place the pan in the oven or on the stovetop (the stovetop method will smoke some, so turn on the fan), or on the gas grill outside. Set the oven, stovetop or grill to high and let the pan get very hot. When you see it start smoking, turn off the fire and let it cool.
5. Repeat the oil treatment and heating treatment twice more.
Now your pan has a good initial cure. Whenever you wash it, and you can wash it with soap and scrubber, dry it over heat. If the pan gets rusty, wash off the rust, spray with oil, and heat-treat again.
Chef Molly Beverly is Prescott's leading creative food activist and teacher. Photos by Gary Beverly.