How to Build a Sourdough Starter
A simple 4-day method from scratch — no scale required
You do not need to buy a starter culture. Wild yeast and bacteria are already on your flour and in your kitchen. This guide walks you through a relaxed four-day build using everyday bread or all-purpose flour, a small jar, and feedings by eye. Once your starter rises predictably after feeding, you are ready to bake with our bake planner.
What You'll Need
- Flour: Bread flour or all-purpose (white) flour — this is what most home bakers use. Whole wheat or rye can help jump-start activity on Day 1 if you have it, but you can build and maintain a starter on white flour alone.
- Water: Standard tap water
- Equipment: A small glass jar with a lid and a spoon
The 4-Day Process
Day 1: The Initial Mix
Add 2 tablespoons of your flour and a splash of tap water to the jar. Don't worry about precise measurements — just mix it by eye until it reaches a thick, creamy paste. Close the jar and leave it on your kitchen counter at room temperature.
Day 2: First Feeding
Open the jar and add another spoonful of flour and a splash of water. Mix it well to maintain that same thick texture. Close the jar and let it sit for another day.
Day 3: Second Feeding
You should start seeing some small bubbles forming. Repeat the exact same refreshing process as Day 2: add flour and water, mix to a thick texture, and let it rest on the counter for one more day.
Day 4: Discard and Feed
The mixture should now be full of bubbles. Discard half of the starter from the jar — this prevents it from overflowing and gives the remaining yeast more strength. Feed the remaining starter with more flour and water, mixing to that same thick consistency.
Once this final feeding ferments and rises, your sourdough starter is active and ready to be used for baking!
Video Walkthrough
Already have a starter? See our guide on Sourdough Starter Maintenance for storage, feeding ratios, and revival tips.