How to Make Sourdough Starter

If you’re new to the world of sourdough baking, I’m so excited to get you “started” (pun intended!). Before you know it, I think you’ll be just as fascinated as I am by the incredible living thing that is sourdough.

Yes, a sourdough starter is a living batter. It is built over several days to cultivate wild yeast from the environment and from the flour itself.

There are many ways to create and maintain a sourdough starter.

You may have read all sorts of warnings…that you must use bottled water, that you should take it on vacation with you and treat it like a child. Relax—it’s really not that complicated.

I’m going to explain to you, step by step, how I created my starter. Along the way I’ll bust some myths about sourdough starters and, hopefully, show you that it’s really a very simple and forgiving process.

Once you have a starter, as long as you feed it periodically it can, theoretically, live forever.

What’s Different About This Process

Although flour is usually inexpensive and easy to come by, it’s always good to create less waste.

So I revamped my process for creating a sourdough starter to dramatically reduce waste. With this new recipe, the total amount of flour used is reduced from 30 oz (about 6 cups) down to less than 2 1/2 cups (12 oz).

The key is to keep the starter very small for the first 6 days of the process.

On day 7 we begin to bulk up the starter. By day 8—usually when a starter is active enough for baking—you’ll have a full 12 oz of 100% hydration starter. That’s enough to bake a loaf of bread and use what remains to continue feeding the starter.

All of my notes and photos for making a starter are still accurate with the revised flour amounts.

Ingredients

• All-Purpose Flour: Medium protein flour is used for growing and feeding the starter.
• Water: You don’t have to use bottled water to make sourdough starter. I mixed two starters side by side, one with bottled water and one with tap water. You can see in the process photos that they behaved exactly the same. As long as your tap water is good to drink and is not excessively chlorinated, there is no need to use bottled water. I baked with both starters with good results.
• Rye Flour (or whole wheat): The wild yeast likes the extra nutrients in the whole grain flour, which gives the starter a bit of a boost and nice flavor. But you can use only all-purpose flour if that’s what you have on hand.

Tips for making a successful Sourdough Starter:

• For best results, weigh your ingredients. The weight of the flour can vary based on how you fill a measuring cup. Weight measurements are most consistent and accurate, especially when working with small amounts in the beginning of the process.
• The warmer the room, the faster your starter will activate. About 75°F is a great temperature for nurturing a starter.
• About day 4 or 5, the starter may start to smell cheesy (like sour milk) and may not rise as much. Don’t give up! The smell will gradually become more yeasty/fermenty and less cheesy. It will sort itself out as random bacteria die out and the good yeasts take over.
• Use a plastic or glass container so you can see the progress of your starter. I like to use plastic, quart-size deli containers. They’re cheap and reusable. Get extra containers so you can transfer the starter to a clean container each time you feed it. They’re also handy for giving away starter to your baking friends.

Detailed Process Photos

Below is a visual overview of how the starter develops over time. Don’t worry if your starter doesn’t look exactly like mine—timing and activity can vary.

• On day 1, mix equal weights of all-purpose/whole grain flour and water.
• Tap water is fine if you have good drinking water.

• From day 1 to day 2 there may not be much activity. Don’t feed it at this point.

• By day 3 there should be some activity. Now you can start feeding.
• Day 4 will see more activity. In my testing, there was no difference in activity between the tap water and bottled water starters.

• The starter will become progressively more active and fragrant.
• Feed about the same time each day.

• By day 8 your starter should be ready to use.
• A starter is ready to bake when it reliably doubles in volume within 4–6 hours of feeding and smells pleasantly yeasty—not sharp or cheesy.

• Baking day. The starter should be bubbly, should have doubled in size in less than 6 hours and have a yeasty and lightly fermented aroma.

Daily Notes on Growing My Sourdough Starter:

• Day 1. Mixed at 11am.
• Day 2. No activity.
• Day 3. Doubled in volume, smelled “grainy”, like wet rye. Not pungent. Fed at 11 am.
• Day 4. Rose to fill the container overnight, then collapsed. Smelled cheesy. Fed at 1 pm
• Day 5. Didn’t rise much, cheesy but less pungent, fed at 12 noon
• Day 6. Rose almost double. Smelled less cheesy, more sharp. Fed at 12 noon.
• Day 7. Rose to double and almost overflowed the container. No cheesy smell, just yeasty and lightly fermented smell.
• Day 8. Rose to fill the container. Smelled yeasty and lightly fermented. Ready to use.
• Day 9. Left at cooler room temp overnight. Rose to double in less than 6 hours and didn’t collapse by 24 hours. Nice yeasty, beery smell. First day baking.

Next Steps:

• Sourdough Baking Guide – My overall approach to sourdough baking, from starter care to baking recipes.
• How to Feed & Maintain Your Starter – Find a detailed schedule for feeding your starter.
• How to Dry Sourdough Starter – Store starter long-term without feeding
• My Best Sourdough Recipes – What to bake once your starter is ready
• My Best Discard Recipes – If you’d rather not throw away discard.