If you’re new to sourdough baking, figuring out when your starter is actually ready to use can be one of the most confusing parts. You feed it, wait, and wonder: Is this it? Can I bake now? I remember being in that exact spot, excited, uncertain, and checking my jar every 30 minutes.
In this post, I’ll walk you through the clear signs that your sourdough starter is active and ready to bake with, plus share what this looks like in real life (not just in theory). Whether you’re troubleshooting a sluggish starter or just need reassurance that you’re on the right track, this guide will help you bake with confidence.
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- What Is a Sourdough Starter?
- How Long Does It Take for a Starter to Be Ready?
- Key Signs Your Sourdough Starter Is Ready
- The Float Test: Is It Reliable?
- Timing Your Starter for Baking
- Using a Levain
- Troubleshooting: Not Sure If It’s Ready?
- Final Checklist: Is Your Starter Ready?
- Final Thoughts on When Your Sourdough Starter Is Ready.
- Other Sourdough Resources You May Find Helpful
What Is a Sourdough Starter?
A sourdough starter is a colony of wild yeast and bacteria used to leaven bread. It also adds that delicious, tangy flavor to the final product.
How Long Does It Take for a Starter to Be Ready?
Generally, it takes about a week for a sourdough starter to become established. The temperature of your home plays a big role in how quickly this happens. The ideal temperature range is around 70–75°F.
If your house runs cold (like mine because my husband runs hot), I recommend using a coffee warmer to keep your starter warm. Some people put their starter in the oven with the light on. I don’t do that anymore because, well, I’ve baked a jar or two (or three…).
On the flip side, if your home is too warm, the starter can eat through all its nutrients too quickly, leaving it hungry and “hoochy.” In that case, feed it more flour than water to keep it happy. You can check out my How to Feed a Sourdough Starter post for more on my feeding method.
The type of flour you use also matters. I recommend starting with rye flour as it has more enzymes for the yeast to feed on. Once your starter is established, you can switch to all-purpose flour. If you’re struggling to get your starter going, check out my No-Fail Sourdough Starter Recipe.
Key Signs Your Sourdough Starter Is Ready
1. It Doubles in Size
This is the number one indicator. If your starter doubles in size within 6–12 hours after feeding, the wild yeast is active and producing carbon dioxide. That’s what creates the bubbles and rise.
2. It’s Bubbly and Active
Look for bubbles on the surface and along the sides of the container. In my experience, larger bubbles are a great sign. Once you start seeing tiny bubbles, the starter is likely past its peak, but that’s okay! I regularly use my starter past its peak or even when it’s technically considered “discard.”
Want to learn more about discard? Check out my What Is Sourdough Discard post.
3. Pleasant, Slightly Tangy Smell
A ready starter will smell yeasty and mildly tangy. If it still smells like raw flour, it’s not ready. If it smells like acetone or alcohol, it’s likely past its peak and just needs to be fed.
4. It Holds Its Rise Before Falling
In the beginning, your starter might rise a little and then fall before doubling. This is common, especially with all-purpose flour. It means the wild yeast ran out of food before reaching full strength. Try feeding it more flour than water.
The Float Test: Is It Reliable?
The float test involves dropping a tablespoon of your starter into a glass of water to see if it floats. If it floats, it’s supposed to be ready.
Personally, I’ve found this test unreliable. Factors like the texture of your starter, how you handled it, or even the type of flour used can affect the results. The signs I mentioned above are a much better way to tell when your starter is ready.
Timing Your Starter for Baking
Feed your starter 4–12 hours before baking for best results. I know that’s a wide range, but every starter is different. You’ll need to experiment a bit to find the right window for yours. I recommend taking notes as you test out different times to keep track of when it peaks.
That said, if I’ve fed my starter at some point the day before, I’ll still use it in recipes that call for an active starter, even if it’s technically “discard.” Don’t stress about using your starter at its peak. If you miss the window, just go ahead and make the recipe anyway!
Using a Levain
A levain is a portion of your starter that you feed separately for a specific recipe. People often do this to adjust the hydration ratio for that bake.
If you’ve read any of my sourdough content, you know I like to keep things simple. I’ve never used a levain. When a recipe called for a specific hydration starter, I just used what I had, and it always turned out fine.
Troubleshooting: Not Sure If It’s Ready?
- Starter didn’t double:
Give it more time (up to 12 hours). Try adding a heat source.
If it rises and falls without doubling, it has run out of food; feed it more flour than water. - Has bubbles but didn’t double:
Likely too runny. Add more flour than water. - Hooch on top (a layer of liquid):
Your starter is hungry. Try using whole wheat or rye, or feed more all-purpose flour than water. - Floats but loaves don’t rise well:
If your starter shows all other signs of readiness and passed the float test, this is likely a bulk fermentation issue. Check out my Bulk Fermentation Guide for help.
In my experience (and from others I’ve talked to), increasing the flour ratio fixes most starter issues.
Final Checklist: Is Your Starter Ready?
- Rising:
Doubles in size within 4–12 hours of feeding - Consistency:
Has done this for 2–3 feedings in a row - Bubbly:
Bubbles on top and along the container sides - Smell:
Pleasant, yeasty, slightly tangy, not overly sour or foul - Age:
At least a week old and consistently fed
(Note: The worst thing you can do early on is neglect it. Be diligent with feedings until it’s fridge-ready!)
Final Thoughts on When Your Sourdough Starter Is Ready.
I remember how excited I was the first time my starter finally rose after many failed attempts. Learning to recognize when your sourdough starter is ready boosts your confidence and makes baking much more enjoyable.
Just remember, it takes time and practice. Leave a comment below with how you know when your starter is ready!
