Sourdough Series Part 1: Understanding Sourdough

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I am so excited for you to begin the process of making sourdough. This is the first of my multi-post Sourdough Series, in which I walk through the basics of sourdough bread baking, daily sourdough routines, tips and tricks, recipes, and much more.

In this post, you'll learn what sourdough is, how the process works, and how to make your own sourdough starter.

Let’s jump in!

What is Sourdough Bread?

Sourdough bread is bread that is raised―or leavened―not with commercial yeast, but with a sourdough starter.

The sourdough starter is a living, breathing thing. It starts as a mixture of flour and water, but it becomes so much more than that.

Through a simple process of fermentation, beneficial microbes that are naturally present within the flour are given time to grow, and that flour-water mixture becomes a vibrant colony of bacteria and yeast.

These beneficial microorganisms thrive on the starches within the flour.

Their life cycle is simple: eat, reproduce, release gas.

And it’s this lifecycle that makes the magic and turns a sticky blob of flour and water into a beautifully fluffy loaf of bread. That carbon dioxide gas that’s released as the microflora consumes the flour causes the dough to rise.

And that’s how a sourdough starter brings life to and raises bread—and works as an alternative for conventional yeast.

The History of Sourdough

Calling sourdough an alternative to yeast makes it sound like it’s a new thing, but it’s not a new thing.

Not at all.

There is evidence even deep into history that home bakers, 1000s of years before they understood the mechanisms of the microbial world, utilized methods of cultivating starter, fermenting grains, and leavening bread. In fact, it wasn’t until the mid-19th century that any method other than this traditional method of leavening bread with sourdough was used.

In the 1850s, Louis Pasteur discovered how yeast works:

Yeast feeds on the starches in flour, producing carbon dioxide.
Carbon dioxide expands the gluten proteins in the flour.
The gluten proteins cause the dough to expand and rise.

A decade later, in the 1860s, the Fleischmann brothers discovered a method to grow, isolate, and separate yeast, and the modern baking era began.

Now the commercial yeast of those days was fresh, required special care, and looked a lot different than the dry active yeast of today, but even so, the Fleishmann brothers’ innovation changed the story of bread baking forever. In the decades that followed, isolated yeast became a household staple, used for everything from soothing cold sores to curing constipation to leavening bread.

In the 1940s, when the United States entered the war, the need to feed troops led to the development of Active Dry Yeast, a product that did not require refrigeration and would activate quickly in warm water.

This was revolutionizing.

The development of active dry yeasts continued, resulting in new highly active yeasts capable of raising dough 50% faster than the original active dry yeast.

With each innovation, however, came a change in the quality of the bread.

Finally, in 1961, the bread-making process saw another massive shift with the industrialization of bread-making through development of the Chorleywood Bread Process. This high-speed, low-cost method took bread making out of our home kitchens and neighborhood bakeries and into factories, leaving flavor, texture, and digestibility at the curb.

Why Sourdough?

So why make slow-fermented sourdough when such quick, cheap options are available?

There are a few reasons.

First, because it tastes so good.

The texture and flavor of traditionally-fermented sourdough bread is unparalleled.

Sourdough is flexible, too. It can be used to make a variety of kids of bread, from soft crumb sandwich bread to springy open-crumb shattery-crusted artisan loaves, from ultra-tangy in flavor to mild to virtually no tang at all.

Secondly, because it’s natural.

When we make bread for ourselves using traditional artisanal methods, we know what we’re getting, and what we’re not.

Traditionally fermented sourdough is much easier to digest than conventional bread. The work of the microbes feeding on the starches during the fermentation process lowers the glycemic index of the bread, breaks down the phytic acid, and degrades the gluten.

For these reasons, many people report that when they eat sourdough bread, they don’t experience the belly ache and the bloat that they’ve come to expect when eating conventional bread products.

Thirdly, because it’s fulfilling.

In this fast-paced world, it feels good to slow down, to make something as simple and satisfying as a hand-crafted loaf of bread. It connects us to our food and to our history, but also to ourselves and to others as we slow our pace, think in steps, and enjoy the ritual of bread-making and bread-eating.

How to Make Your Own Sourdough Starter

So, how do you make a sourdough starter?

Sourdough starter is crafted by cultivating the naturally-occurring bacteria and yeast that is present all around us. It’s on our hands. It’s in the air. It’s on the flour itself. And with a little time and tender care, it will grow into a flourishing colony that is your sourdough starter.

Two Methods of Crafting Starter:

Because yeast and bacteria are present everywhere, there are many ways to craft a starter. All you really need is a little starch for the microbes to feast upon. There are two methods that I use and teach: the flour method and the raisin method.

The Flour Method

The flour method utilizes the microbes that are naturally-present within the flour. Flour is mixed with water and left to sit in a warm place. Given enough time, the microbes feed on the starches in the flour and build strength.
Every day for a week, the starter is refreshed by pouring off half and then feeding the remaining with more flour and water.
By the end of a 7-day period, the flour-water mixture should contain a vibrant microbial colony. It’s ready to be used for raising dough and baking bread.

The Raisin Method

The raisin method utilizes the microbes that are naturally present on raisins to create a yeast water that will later be used to inoculate flour and turn it into a sourdough starter.
To make the yeast water, raisins, honey, and a little bit of sugar are stirred together in water and left to ferment over the course of 7 days. The yeasts on the raisins feed on the honey and sugar-water and populate the water.
After 7 days, the yeast water is added to flour and the starter is born.
The newly created starter should be fed in the standard feeding practice a few times—pouring off half of the mixture and stirring in equal parts flour and water—until it bubbles up and passes the float test. Then it’s ready to use.

Which Method To Use

So which method should you use?

Both methods will produce an active starter for baking within a very similar amount of time. And I like each for different reasons.

The flour method uses what most people already have on hand—flour and water. It’s simple to do and really not time consuming, but you have to dump and feed everyday. It’s another thing to remember, and there is a little bit of waste with the pouring off.

The raisin method is probably my slightly more favorite of the two. The raisin water sits on the counter for a week, and all you need to do is shake it every so often. There’s much less waste and, at least according to my experience, that first bake gets a little bit of a stronger rise than the first bake with the flour method.

Even so, either method will get the job done, and I teach both methods, because they are both adequate. It’s good to know more than one way to do a thing. It makes us more resourceful and adaptable bakers.

Just decide which method you want to try, and get started culturing your sourdough starter. Or, if you’re curious, make both and compare your results, just like I did.

Now, what are you waiting for? Get in the kitchen and make that starter!

Grab your printable download for sourdough starter here:

Sourdough Starter