Ripe Sourdough Starter: What does "ready to use" look like?

Sift’s Spring issue goes into sourdough baking in depth, with articles on sourdough breads and the sweet side of sourdough. To complement those recipes, we’d like to share this Techniques column. How do you know when your sourdough starter is ready to bake with? Let’s take a look.
We’ve answered hundreds of questions on this topic, but in this case it seems some pictures could well be worth a few thousand words.
sourdough Starter

Wake up your sourdough starter

Your starter has been tucked safely in the refrigerator for… awhile. Ten days, maybe longer. It’s separated, with a few tiny bubbles in the bottom, and a layer of grayish-looking alcohol on top. This is the sight that generates a lot of phone calls to our hotline. Can this possibly be OK? Is it dead?

Despite its current uninspiring appearance, this starter is still capable of doing great things.

sourdough Starter

Your sourdough starter’s first meal

Stir everything back together (some people just pour off the top layer, which is OK, too), discard half, and feed the remainder with equal weights of flour (a scant 1 cup, 4 ounces) and water (1/2 cup, 4 ounces). Mix well, cover, and leave on the counter for 12 hours. Repeat the discard and feeding process every 12 hours, leaving the starter on the counter. After a few feedings, you’ll see the starter becoming more and more active, doubling in size in a shorter time.

Looking for ideas of what to do with that discarded starter? Visit this page to get a whole collection of recipe ideas.

sweet sourdough baking via@kingarthurflour

Get ready to bake

This is the same starter after a few days of the regular feedings described above. We stirred, discarded, and fed it with flour and water at 8 a.m. (2 hours ago). Now we’re going to watch its development. See the number and size of the bubbles increasing?sourdough starter via@kingarthurflour

Active, but not ripe, sourdough starter

The same starter at 1 p.m., 5 hours after feeding. It’s beginning to expand, and has many more bubbles. If you watch it for a minute, you can see the bubbles forming and coming to the surface in slow motion. This is an active starter, growing and expanding, producing bubbles of carbon dioxide. But it’s not yet ripe (at the top of its yeast and bacteria growth arc), nor at full strength for raising dough.sourdough starter via@kingarthurflour

Ripe and ready to go

The same starter at 4 p.m., 8 hours after feeding. It’s doubled in volume, and shows signs of just beginning to sag under its own weight. This is active starter that’s also ripe, ready to be added to bread dough to perform its sourdough magic. After mixing it into dough, then some rising and folding, the dough can be shaped and refrigerated overnight to be baked tomorrow.

sourdough Starter

The best way to measure sourdough starter

An important thing to note about measuring sourdough starter: The more bubbles in it, the less a cup of active, ripe starter weighs. Measuring by volume can mean you have more or less starter in your cup, depending on where it is on its growth curve. That’s not a deal breaker for your recipe, but having a different amount of starter than called for may change the rising times and finished size of your loaf. To be sure you have the lifting power you need, measuring ripe starter by weight is always a better choice.

Once you gain confidence that your starter is vigorous, you can move its “get ready” feeding to the evening, knowing your starter will be ripe next morning to mix into your dough.

Your sourdough baking adventures await. We have lots of ideas (more than 150 recipes) to help you navigate this tasty and rewarding style of baking. Be sure to visit our sourdough guide for more in-depth information about creating, maintaining, and baking with sourdough.

At Sift, we live and breathe baking, and hope you’ll join us. Baking together is always more fun.

Susan Reid

Chef Susan Reid grew up in New Jersey, graduated from Bates College and the Culinary Institute of America, and is presently the Food Editor of Sift magazine. She does demos, appearances, and answers food (and baking) questions from all quarters.


  1. Janella

    How long is too long before using starter? My daughter gave me some starter (the bit she took off hers, if that makes sense) in late October. I haven’t used it yet. Should I get rid of it or can I still use it?

  2. Karen Schupp

    Will feeding the starter more often make it more sour? I’m finding that I’m not getting as tangy taste as I like. I do add a bit of citric acid to boost but I’m wanting even more tang.

    1. The Baker's Hotline

      Hi Karen. The best way to have a stronger tangy flavor in your bread is to let the bread dough rise in the fridge overnight rather than on the counter for a few hours. Feeding your starter twice a day if you’re keeping it at room temperature is perfect for keeping it healthy and vital. The sourness will really come from the bread. Annabelle@KAF

  3. Laura Harvey

    When the starter is ready to use, do you stir it before measuring it out? I think you don’t need to if you are weighing it, but otherwise I’m unsure.

    1. The Baker's Hotline

      Hi Laura! You’re correct — if you’re weighing it, no need to stir, but if you’re measuring by volume, definitely stir it down first. Annabelle@KAF

  4. Marianna

    I am making sourdough starter first time ever. I used regular all purpose flour. It’s day 4. I fed my starter only after 48 hours first which I think was quite late. I might have used too much water as next day my starter separated. There were 3 layers in the jar. Not active layer flour at the bottom, liquid in the middle and active layer on the top. The smell become quite pungent. Almost vomit like. I drained the liquid, discarded 2/3 of the starter and fed it again. 12 hours later, the separation happened again, but not so visible and the smell was the same. I again drained the liquid, kept only 1/3 and fed it again. Why the separation keeps happening? Is it supposed to smell like that? Should I keep going or restart with rye flour?

    1. The Baker's Hotline

      Hi Marianna, it sounds like something might have gone amiss with your starter. The smell of sourdough starter can be strong and overpowering, but it should be tangy and fresh (not putrid). You might want to start again using whole rye or whole wheat flour initially, and then switch to all-purpose flour. If possible, use a scale to measure your ingredients by weight to ensure your starter has the right consistency. Mix the starter, flour, and water each time until it’s completely combined and homogenous. This thorough mixing and daily feedings should prevent separation. If a bit of liquid forms on top (know as “hooch,”) stir it back into the starter before discarding and feeding. Good luck and happy baking! Kye@KAF

  5. Lou Darland

    I’ve just purchased the starter and have fed it twice. How long does it take to be ripe and ready to use? I’m looking forward to making my own bread. Should I double my starter now if I want to make 2 loaves of bread when it eventually gets ripe


    1. The Baker's Hotline

      Hi Lou, we recently put together a full Sourdough Baking Guide that includes a helpful video demonstrating what your starter will look like when it’s ready to bake. (The amount of time it takes before it’s ready to bake will vary from starter to starter.) Here’s what we say in the guide: “Your new starter is ready to bake with when it’s reliably becoming very bubbly and doubling in size within 6 to 8 hours of feeding. (This is why it’s useful to feed your starter in a clear, straight-sided container, so it’s easy to track its upward progress.) Ripe starter will be viscous, not thin; and if you taste a tiny bit, it will be nicely balanced between rich flavor and acidity.”

      As for your question about doubling your starter, you can build the volume of your starter slowly once you’re close to getting ready to bake; increase the volume of flour and water that’s added in the last two or three feedings before you bake. Aim to use a ratio of equal parts starter-flour-water by weight for best results. Good luck! Kye@KAF

  6. Ginger

    Absolute beginner here. Day eight of trying to coax flour and water into a viable sourdough starter.

    I rigged a proofing box out of a styrofoam cooler and a light bulb, and it’s keeping the jars between 74-80 degrees.

    I started with a mix of 50/50 rye flour and AP flour, feeding twice daily with AP flour. Using a 1-1-1 starter, flour, and water ratio.

    There was a lot of rising activity on days two and five, hooch appeared on days three, four and five.

    Last few days no rise and fall and only small bubbles. A very thick skin forms on the top – like you get when you make pudding, only denser. Underneath that skin the slurry is puffy and light, though it does not rise.

    It smells like fresh flour with a whiff of ferment. It tastes very tangy/vinegary/sharp and feels almost fizzy on the tongue.

    Is that skin on the top a problem or a natural phase? What could be causing it? Any advice on how to manage it? Thanks very much.

    1. The Baker's Hotline

      Hi Ginger, it sounds like you might not be covering your starter sufficiently so it’s drying out and forming a skin. Try placing a lid slightly ajar even if the starter is kept in a proof box. Otherwise, it sounds like you’re right on track to building a beautiful and healthy starter. Check out our full Sourdough Baking Guide for visual examples (amazing videos!) of what your starter should look like when it’s ready to bake. Good luck! Kye@KAF

  7. Darlene

    Good morning!
    I use both the Cake enhancer and the Roll improver from time to time. Mostly when I make yeast dough products like cinnamon rolls. They both work well but it seems to me that the Roll improver makes for better Cinnamon rolls.

    I guess my question is basically what is the difference between the two products other than the Roll improver has a yellow cast to it and I think it browns faster in oven.

    Just something that boggles my mind and you can better inform on “why”! You are the experts and “me” just an old scratch cook.

    1. The Baker's Hotline

      We’re happy to help clarify the difference between these two products, Darlene. The description of Cake Enhancer on the product page is helpful in explaining what exactly this tenderizing ingredient is: “It’s rice starch, polyglycerol ester, and mono- and diglycerides of fatty acids – complicated looking words, but nothing to be afraid of. These fatty acids come from vegetable fats, and act as emulsifiers, allowing fats and liquids to combine more easily. They also serve as stabilizers and texture enhancers. Widely used in commercial baked products, they keep baked goods fresh and soft, and help cakes stay light and fluffy.” The Easy Roll Dough Improver is a combination of nonfat dry milk, unbleached enriched flour, rye sourdough (for flavor), and dough conditioner. This combination of ingredients allows the gluten in dough to relax so rolling out the dough is easier. As you noted, it also helps with browning and adds some depth of flavor. They’re both helpful products to have on hand in the kitchen; choose the one that makes the most sense for what you’re baking. Cake Enhancer for cakes, soft breads, muffins, and even scones; Easy Roll Dough Improver for cinnamon rolls, pizza crust, sticky buns, and any other sweet or enriched each dough that gets rolled out before being shaped. Kye@KAF

  8. Timea

    I’ve been feeding my starter since last weekend. Last night my starter had doubled in size but this morning it collapsed back. Do you think I can still use it today?
    I also feed it once every 24 hours? Is that bad practice?

    1. The Baker's Hotline

      Hi Timea,
      It’s normal for starters and rise and then fall in the way you’ve described. If your recipe called for fed starter, you’ll want to use your starter before it collapses. Take what you need for your recipe slightly before it reaches its peak volume; that way it’ll still have some rising energy left in it when you use it in your dough. If your recipe calls for unfed starter, it’s fine to go ahead and use the collapsed starter. Feeding your starter daily is fantastic practice! If you’re able to keep up with that schedule, then more power to you. You’ll be rewarded with a very healthy, active starter. Good luck and happy baking! Kye@KAF

  9. Julie

    I’ve been feeding my starter since last Thursday. It seems to double in size at each feeding, but I’m still not sure if it ready to give away and done.

    If so, are you saying person must feed it and wait before they use it. Then reserve at least a 1/2 cup to feed again on another 10 days?

    Also, each time you use it must you let it sit overnight?

    Had starter years ago, but put milk, sugar and flour in it.

    1. The Baker's Hotline

      Hi Julie, congratulations on beginning your very own sourdough starter! It sounds like your starter is on track to being healthy, mature, and ready to bake with! We’re wondering what’s keeping you from baking if it’s doubling in size after each feeding — we think you should give it a go! If you give some of your discard away to another baker, they can treat that as their very own starting culture. They can begin feeding it with equal amounts of flour and water by weight. They shouldn’t need to feed it for a full 10 days before using since you’ll already have done much of that maintenance for them. As soon as it doubles in size after each feeding, gets bubbly, and smells sour, you’re ready to bake! The starter should rest at room temperature for a few hours after each feeding to let it “digest;” it doesn’t need to sit out for a full 12 hours overnight. We hope this helps clarify some of your lingering questions, and we invite you to call the Baker’s Hotline if you’d like to talk about your starter in more detail. We’re here to help at 855-371-BAKE (2253). Kye@KAF

  10. Tara

    Hi! I was given a sourdough starter to care for while a friend is travelling. I’m wondering if I can freeze some as a backup in case I end up killing the starter. Can you freeze the starter and then bring it back to life?

    1. The Baker's Hotline

      We’ve found that freezing isn’t the best way to put a starter on hold, so to speak. It ends up killing most of the yeast and bacteria cultures, so essentially you just end up beginning a new starter from scratch when you try to revive the old culture. You might want to try drying your starter using this technique here. It tends to work better than freezing, so we encourage you to give it a try. Happy baking! Kye@KAF

Post a comment

Your email address will not be published. Required fields are marked *