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With a little patience and just two ingredients, the ancient secret to stellar bread can be yours.
ByChris Malloy
Updated on February 29, 2024
Making a sourdough starter—a live culture of wild yeasts that you feed and then use to "start" a loaf—may seem intimidating. Sure, you can buy a packet, but if you're wondering how to make sourdough starter from scratch, you might be surprised at how simple it is.
To make sourdough starter, all you need is flour and water, a digital scale, a jar, and about 5 minutes a day for up to a week. The result is a healthy home-baked loaf that's more complex, delicious, and less expensive than one you grab off the grocer's shelf. Let us guide you through the process that's totally doable.
How Is Homemade Sourdough Starter Different?
Bread is a fermented food—like wine, kombucha, and kefir—and, in bread, yeast initiates that fermentation.
Commercial sourdough starter—whether sold at your grocer's or online—is fermented using a packet of yeast. Those packets generally contain just one strain of yeast.
Homemade sourdough starter is fermented using wild yeasts, which are invisible and occur naturally in the environment, floating in the air indoors and out.
A homemade sourdough starter calls on many strains of wild yeasts, creating a better homemade sourdough bread with a more complex fermentation than can be attained with commercial yeasts.
Sourdough Origins
Sourdough likely dates back to the origin of bread itself in Ancient Egypt. This civilization made sourdough loaves without the modern marvels of organic flour, digital scales, and tap water.
Equipment / Tools
- Clean, empty quart-sized jar
- Digital food scale
Materials
- Unbleached organic white flour
- Water
Instructions
How to Make Sourdough Starter
Some starter recipes call for other flours, like whole wheat or rye, but let's keep things simple with white flour. It's important to use unbleached organic flour to ensure no unwanted chemicals hamper the gentle development of your starter.
Weigh the Empty Jar
Note the weight of your clean, empty jar (in grams) before adding flour and water to it. You'll need to know that weight throughout the feeding process.
Mix Flour and Water
- Using your scale, measure 150 grams of flour and 150 grams of warm water, and then add them to the jar.
- Mix the jar contents with a spoon until you have a uniform beige concoction.
- Leave the jar uncovered for about an hour, and then cover the jar loosely with a cloth.
- Now, wait until the same time tomorrow. Over the first 24 hours, wild yeasts are working. They're slower to act than commercial yeasts, but they're kicked into steady gear.
Feed Your Starter on Day 2
- About 24 hours from starting, discard over half of the starter, keeping about 80 grams. To calculate the weight of your starter, subtract the weight of an empty jar from the weight of the one holding your starter.
- Add 100 grams of water and 100 grams of flour to the starter and mix well.
- Leave the jar uncovered for about an hour. Next, cover loosely with fabric, and then set the jar aside until the same time tomorrow.
Repeat on Day 3 and 4
On Day 3 and 4, repeat the feeding process again. By then, you'll notice your starter has developed a pungent tang, like what you'd smell if you put your nose in a fresh sourdough slice.
Continue Daily Discarding and Feeding Until Day 7
Continue the daily discarding and adding on Day 5 through Day 7, and your starter should be ready (results may vary). The process is dependent on several variables—such as temperature, environment, and flour type—so allow for some flexibility.
You'll know your starter is ready when it's gooey and bubbly, quicker to rise up your glass, and develops a pungent smell just a few hours after feeding.
Store Sourdough Starter and Feed Weekly Until Ready to Use
Congrats on your homemade sourdough starter! After a week, you've probably developed an intimate understanding of your sourdough starter's behavior, such as what it needs and how it changes over time.
Stored in the fridge, your starter still requires that feeding procedure, but only weekly rather than daily. Instead of discarding excess starter, use it as the leavening agent to start a fresh loaf of sourdough bread.
Frequently Asked Questions
What is going on in the jar when the starter is feeding?
By adding more flour daily, or "feeding" your starter, you're providing more food for wild yeasts to consume. Without this daily influx of fresh food, the wild yeasts living in the starter would start to die. You'll know this is occurring if it starts to makehooch, which is yeast excrement in the form of a harmless liquid that forms at the top of the starterand smells like alcohol (or nail polish remover).
Why do we have to discard so much starter?
When making sourdough starter, if most of it isn't discarded daily (before feeding), the appetites of the yeast would be so great that you'd end up adding more and more flour to ensure they're all fed. Discarding some first allows you to add sufficient fresh food daily yet maintain a manageable amount of starter. Also, not discarding your starter can cause high acidity levels that can adversely affect the microbes and the taste of your loaf.
5 Tasty Ways to Use Sourdough Starter (That Aren't Bread)
Sources
Real Simple is committed to using high-quality, reputable sources, including peer-reviewed studies, to support the facts in our articles. Read our editorial guidelines to learn more about how we fact check our content for accuracy.
Thirty years of knowledge on sourdough fermentation: A systematic review.Trends in Food Science & Technology. 2021;108:71-83.
