How to create a sourdough starter
- Tartine Maple
- May 2, 2025
- 3 min read
There's something almost magical about creating a sourdough starter from scratch. With nothing more than flour, water, and a little patience, you can cultivate a living culture of wild yeast and beneficial bacteria that will leaven your bread for years — even decades — to come. No packets of commercial yeast required.
But if you've tried before and ended up with a sad, lifeless jar of paste, you're not alone. A sourdough starter can feel fickle at first, and a lot of beginner guides skip over the small details that actually make the difference between success and starting over. That's why this guide breaks it down day by day, so you always know exactly what to expect and what to do next.
Ready to grow something delicious? Let's get started.
3 things to consider to improve your chances of success:
Warm environment: you will be more successful in the spring or summer, although it’s not impossible when cold, it’s much slower
Good quality flour, whole grain if you have
Filtered water. Or tap water that you let sit uncovered for 24 hours. And use it lukewarm.
The steps are as follow:
Day 1: in a container (4 cups large, plastic or glass), mix 50 gr of warm water (filtered water preferable) and 50 gr of flour (the better quality your flour, the better chance of success; whole wheat, organic… are preferred). Cover the container with a cheesecloth secured with a rubber band, or plastic wrap with a few little holes. Place in a warm spot (20 to 25 C). An oven with just the light turned on is a great spot if your house is cold. That’s it, wait 24 hours.
Day 2: you might have tiny bubbles yet, or not. That’s ok. Regardless, add to the container, another 50 gr of warm water and 50 gr of flour. Mix, cover, wait another 24 hours.
Day 3: now you should see a little froth of bubbles in your starter. If you don’t yet, no worries, keep going. The smell might be off putting, but that’s a good sign. Add to the container, another 50 gr of warm water and 50 gr of flour. Mix, cover, wait another 24 hours.
Day 4: if you had the funky smell yesterday, now it should smell better, like a nice, sweet lacto fermentation. Good sign! Add to the container, another 50 gr of warm water and 50 gr of flour. Mix, cover, wait another 24 hours.
Day 5: If nothing has happened yet by day 5, forget about it. Throw everything away and start over again, you haven’t caught any yeast…
Otherwise, your starter should be growing in size and bubbling nicely. It’s time to scale it down and feed it a better ratio; discard it all but 25 gr. Feed this 25 gr of starter with 25 gr of warm water and 25 gr of flour. Mix, cover, wait another 24 hours.
Day 6: Your starter should have doubled in size at least, and bubble a lot. That means you got yourself a healthy starter! It’s now time to feed it it’s daily ratio. I like to feed my starter a ratio of 1-2-2. That means, for 20 gr of starter (1 ratio), I mix in 40 gr of warm water (2 ratios) and 40 gr of flour (2 ratios). You can do the same with more or less.
Keep doing this for a few more days (even a couple of weeks) before attempting to make a recipe. You want to make sure your new starter is strong and healthy!
If you want your starter to always be ready for a recipe, feed it daily its 1-2-2 ratio and leave at room temperature, and make sure it doubles or triple in size within 12 hours after feeding: that means your starter is healthy enough for making a recipe!
If you want to see this tutorial in image, check out my Instagram story highlight: Starter Tutorial
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