A sourdough starter is a living culture of flour and water that captures wild yeast and bacteria to leaven bread naturally. Making one from scratch takes about a week of daily feedings, but needs only two ingredients and a little patience.
What you'll need
- Whole wheat or rye flour
- All-purpose flour
- Room-temperature water
- Clean jar
- Kitchen scale
- Spoon
- Loose lid or cloth
Step by step
- Mix the first batchCombine about 50 grams of whole wheat or rye flour with 50 grams of water in a jar. Whole grain flour helps kick-start fermentation.
- Let it sitCover loosely and leave it at room temperature for about 24 hours. You may not see much activity on the first day, which is normal.
- Begin daily feedingsEach day, discard most of the mixture and feed the remainder with equal weights of flour and water. Switching to all-purpose flour after the first day or two is fine.
- Watch for bubblesOver several days you should start seeing bubbles and a sour, tangy smell. This shows the culture is coming to life.
- Feed twice a day if activeAs it becomes more active, feed it twice a day to keep up with the growing yeast. Keep the jar warm to encourage activity.
- Test for readinessThe starter is ready when it reliably doubles within a few hours of feeding and looks bubbly. At that point you can use it to bake.
Handy tips
- Keep the starter somewhere warm, since cool kitchens slow fermentation considerably.
- Use a rubber band or mark on the jar to track how much it rises after feeding.
- Consistency matters more than exact amounts, so feed at roughly the same times each day.
Heads up
- A little liquid or a sour smell is normal, but throw the starter out if you see fuzzy mold or pink or orange streaks, which signal unsafe contamination.
FAQ
How long does it take to make a starter from scratch?
It usually takes about five to ten days for a starter to become active enough to bake with. Warmer kitchens tend to be faster, while cooler ones take longer.
What flour is best for starting one?
Whole wheat or rye flour is great for the first days because it ferments quickly. Many people then switch to all-purpose flour for regular feedings.
How do I know my starter is ready to bake with?
It should reliably double in size within a few hours of feeding, smell pleasantly sour, and be full of bubbles. A spoonful that floats in water is another common sign.