How to Feed Your Sourdough Starter
One of the biggest misconceptions about sourdough is that keeping a starter alive is difficult. Once you understand what your starter actually needs, feeding it becomes a simple part of your baking routine instead of something you have to overthink.
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At its core, feeding a sourdough starter simply means giving the wild yeast and beneficial bacteria fresh flour and water so they can continue growing. The exact feeding ratio you choose depends on how often you bake, how warm your kitchen is, and when you need your starter to be ready, but the process itself is always the same.
If you're just getting started, don't worry about finding the “perfect” feeding schedule. Learning how your own starter behaves is far more important than following someone else's routine.
Why Does a Sourdough Starter Need to Be Fed?
A sourdough starter is a living culture made from flour and water. Inside that mixture are wild yeasts and beneficial bacteria that feed on the carbohydrates in the flour.
As they consume that food, they produce carbon dioxide, which helps your bread rise, along with the acids that give sourdough its signature flavor. Eventually the available food is used up, which is why the starter needs to be refreshed with more flour and water.
A healthy starter will rise after feeding, become full of bubbles, and eventually fall back down as it finishes fermenting. That cycle repeats every time it is fed.
Understanding Sourdough Feeding Ratios
If you've spent any time reading sourdough recipes, you've probably seen ratios like 1:1:1, 1:2:2, 1:3:3, or 1:5:5. These numbers simply tell you how much starter, flour, and water to use.
The ratio is always written in this order:
Starter : Flour : Water
For example:
| Ratio | Example Feeding |
|---|---|
| 1:1:1 | 25g starter, 25g flour, 25g water |
| 1:2:2 | 25g starter, 50g flour, 50g water |
| 1:3:3 | 20g starter, 60g flour, 60g water |
| 1:5:5 | 10g starter, 50g flour, 50g water |
One thing that often confuses beginners is seeing ratios like 2:2:2 or 3:3:3. These aren't actually different feeding ratios because they still use equal parts of everything. A 2:2:2 feeding is mathematically the same as a 1:1:1 feeding. The only difference is the total amount of starter you're making.
When Should You Use Each Ratio?
Each feeding ratio simply changes how much fresh food your starter receives.
A 1:1:1 feeding contains the least amount of fresh flour and water, so your starter will usually become active the fastest. This is a great everyday feeding if you plan to bake within a few hours or your kitchen stays fairly cool.
A 1:2:2 feeding gives your starter more food, making it one of the most versatile options for daily maintenance. Many bakers find it provides a good balance between predictable timing and healthy growth.
A 1:3:3 feeding works well when you need your starter to last longer before reaching its peak. It's a popular choice for overnight feedings because it gives the yeast more food to work through.
A 1:5:5 feeding provides the largest amount of fresh flour and water and generally takes the longest to peak. This can be helpful in very warm kitchens or anytime you need your starter to stay active for a longer period without collapsing.
There isn't one “best” ratio. The right choice depends entirely on your schedule.
How Temperature Affects Your Starter
Temperature has just as much impact on your starter as the feeding ratio itself.
A warm kitchen speeds up fermentation, which means your starter will rise and use up its food much more quickly. A cool kitchen slows everything down.
That's why the exact same starter fed the exact same ratio may peak in four hours during the summer but take eight hours during the winter.
If your starter keeps peaking long before you're ready to bake, try increasing your feeding ratio rather than feeding it more often.
What Flour Should You Use?
Most healthy sourdough starters do perfectly well with unbleached all-purpose flour or bread flour.
Whole wheat and rye flour contain more nutrients and naturally occurring microorganisms, which is why they often make a sluggish starter more active. Many bakers like to include a small amount of whole wheat or rye during feedings, although it certainly isn't required.
I cover the pros and cons of each type of flour in much more detail in the best flour for sourdough starter.
How Often Should You Feed a Sourdough Starter?
The answer depends on where you keep it.
A starter stored at room temperature generally needs to be fed about once every 24 hours. In a very warm kitchen it may need feeding every 12 hours because fermentation happens more quickly.
If you store your starter in the refrigerator, weekly feedings are usually enough for maintenance. Before baking, simply bring it back to room temperature and give it one or two feedings until it becomes active again.
The nice thing about refrigeration is that you don't have to feed your starter every day if you only bake occasionally.
Should You Discard Starter Before Feeding It?
Yes, in most cases you'll remove part of your starter before adding fresh flour and water.
This isn't because the discarded portion is bad. It's simply a way to keep your starter from growing into a gallon-sized bucket that requires pounds of flour every week.
Many bakers keep only 10 to 30 grams of starter for regular maintenance, then build a larger amount whenever they're preparing to bake.
If you don't want to throw the discard away, save it for pancakes, crackers, muffins, cookies, and countless other sourdough discard recipes.
How Can You Tell When Your Starter Is Hungry?
A hungry starter will usually tell you.
It may have risen and completely fallen, developed a layer of liquid called hooch, or smell much more acidic than usual. You might notice aromas similar to vinegar, yogurt, or even nail polish remover if it has gone quite a while without food.
These are usually signs that your starter has simply used up its available food and is ready for another feeding.
When Is a Starter Ready to Bake With?
A sourdough starter is usually strongest when it has reached its peak.
At that point it should have risen significantly, contain bubbles throughout the jar, and still have a rounded or slightly domed top. Once it begins collapsing, the yeast is still alive, but it has already consumed much of its available food.
Learning to recognize your starter's peak is much more reliable than using tricks like the float test, which doesn't always give accurate results.
Common Feeding Mistakes
Most sourdough problems come down to just a few simple mistakes.
Using measuring cups instead of a kitchen scale can throw off your feeding ratios because flour is much lighter than water by volume. Feeding a starter before it has had time to become active can also weaken it by continually diluting the yeast population.
Another common mistake is chasing someone else's schedule instead of watching your own starter. Every kitchen is different, and factors like temperature, humidity, flour type, and even the season can affect how quickly your starter ferments.
The best habit you can develop is paying attention to how your starter behaves rather than watching the clock.
Final Thoughts
Keeping a sourdough starter healthy isn't about memorizing complicated formulas or following rigid schedules. It's simply about giving a living culture enough fresh flour and water to stay active.
Whether you choose a 1:1:1 feeding for a quick bake, a 1:3:3 feeding for an overnight rise, or a 1:5:5 feeding to stretch the fermentation a little longer, the goal is always the same: provide enough food for the yeast and bacteria to thrive.
Before long you'll stop worrying about the numbers and start recognizing exactly what your own starter needs. That's when sourdough really starts to become enjoyable.
