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. Claude guermont

    Why through away so much of the levain ,never I dump any of my starter.i have been baking French levain bread for 30 years and it come out great ,only in America I have seen so much waste.i ll give you my recipe if want it,no waste and delicious!claude

    1. Susan Reid, post author

      Claude, we’d be happy to get your recipe. We’re also willing to bet your levain gets regular exercise, and doesn’t get to the sad, separated state you see in the first photograph.
      When that happens, it’s important to rebalance the acid level of the levain’s mixture. Susan

    2. Janet

      I would like to have your recipe for your levain, Bread is my favorite thing to bake, and am always looking for new way to make bread

    3. Susan Reid, post author

      Janet, check out any of our sourdough recipes. I’m quite fond of this one for an everyday loaf. If your starter is in good shape, you can make it without the added yeast. Susan

    4. The Baker's Hotline

      Hi D. Smith, we’re not quite sure if you’re asking us for a recipe or Claude, but if we can help please feel free to give our Baker’s Hotline a call at 855-371-BAKE(2253) so we can get you the information you’re looking for. Kye@KAF

  2. Sally Tebbet

    What is the reason for discarding part of the sourdough starter? I never do that and I never have any trouble with my breads. I use only starter as leavener, no commercial yeast.

    1. Susan Reid, post author

      Hi, Sally. The reason for discarding half the starter is to keep the level of lactic and acetic acid from skewing the PH of the overall mixture. This isn’t as critical if you’re baking with your starter regularly; it’s more important for a starter that’s been laying fallow for an extended period of time. Susan

  3. Tom

    If you take the sourdough discard, add an equal volume (not weight) of King Arthur flour (I like to use 1 1/2 cups flour – 1 1/4 c KA AP and 1/4c KA Whole Wheat) to 1 1/2 cups stirred starter for 3 thin crust 12″ pizzas) and 3/4 TBSP of salt, knead for about 5-7 minutes and then add 2 TBSP olive oil and knead that in until the dough is smooth and supple and divide into 3 equal balls and let them sit out, covered, for a couple of hours, you’ll have the best thin crust pizza dough ever. If you freeze it, just remove it from the freezer about 3 hours before you want to use it.

    Not sure if I’m allowed to link to a picture but if I am here it is…if not…sorry!

    1. Susan Reid, post author

      Hi, Tom. I’m with you; I will very often use my discard as the beginning of amazing pizza dough. Thanks for the amounts; that will be helpful to a lot of people. Susan

  4. Jeannine

    thank you! I’m a “visual learner” and this sure helped me along with the explanations. My starter is in my fridge “as we speak” awaiting a re-birth!

  5. Mary

    I seem to be mentally blocked when it comes to the “starter”.
    I have a lot of recipes that I’d love to try. Do I have to make a starter for each recipe, or do I just keep the original and keep feeding it and how long can I keep it going and how?

    1. Susan Reid, post author

      Hi, Mary. Once you have a starter established, it becomes your baking buddy. All you have to do is feed it once or twice a week, and rev it up a day or so before you plan to use it, following the information here. It’s just flour and water, don’t be scared. We know bakers who have had starters (with pet names) for decades. Susan

  6. NancyC

    Excellent post. Thanks for the explanation and visuals. Next time I do gf sourdough the odds are better it will turn out. GF dough does not behave as wheat dough so I would probably leave the dough on the counter to rise and see if the starter has enough oomph to raise the dough. Once I am confident my dough will rise I could try a refrigerated overnight rise. Gluten free dough can be so fussy. Thanks!

    1. Susan Reid, post author

      Most welcome, Nancy. GF starters tend to move faster, we find. The combination of starches gives the yeast a lot of food to eat. Susan

  7. George A Tattersfield

    I am so happy to read this article. My basic go to recipe is a modified version of your “Clay’s sourdough/ with grains and seeds “. I have always wondered if my starter has the horse power to get the job done. I use additional yeast in my recipe. I make six pounds of dough for three large loaves. Both the initial rise and the second take less than 45 minutes so something must be going on. It makes wonderful bread but I am considering using only whole wheat flour instead of 50% white flour in order to make it more wholesome. Btw I also add extra gluten to help with the rise.

    I use the starter about 8 hours after refreshing it and it is not bubbling or doubled. Should I give it some extra refreshing?

    1. The Baker's Hotline

      Consider a couple days of feeding the starter twice a day before you bake. Surely, you’ll see the increased activity of the starter and it will be evidenced in your baked breads. Happy Baking! Irene@KAF

    2. Peter Cartella

      I feel the ambient temperature has a big effect on the lift of my sourdough starter.

      I place a cup of water in the microwave and heat it up for 2 or 3 minutes.

      I then remove the cup and place a thermometer along side my covered bowl of mixed dough.

      i maintain 78°F to 80°F the whole time by monitoring the temperature, removing the dough and thermometer then reheating the cup of water as needed.

  8. Teresa Sutton

    I am only able to use your Gluten Free products. Is the sourdough starter gluten free? Or is there a way to make one that is gluten free?

    Thank you,

    1. Adrienne P.

      From my understanding, and looking at many articles on the gluten present in regular sourdough. It is gluten free (100% I am not sure) but I have found I am able to consume sourdough breads without the GI problems I get when I eat reg wheat breads. Of course we are talking real.sourdough, not sour tasting breads made by adding flavorings or vinegars. These KA tutorials are wonderful, I am exploring sourdough now.and this is giving me much more freedom to enjoy real bread.

    2. Susan Reid, post author

      Adrienne, Sourdough loaves are NOT gluten free, but there is growing evidence that the long-fermentation times that sourdough breads go through before baking make the finished breads easier for gluten-sensitive folk to tolerate. Susan

  9. Thom B

    Hey .. a little flour and water down the drain is not a terrible thing, but I’ve made some dang good pizza dough from my ‘discards’ and it freezes quite well.

    Just add KA bread flour/spring water to discard starter for proper consistency, let stand for 4 hours, then freeze or make a great pizza !!

    Maybe not ‘picky’ enough for some, but sure works for me …. 🙂

    1. Charles Nuttall

      I agree. I don’t throw anything away. I’ve neglected sourdough starter for months before successfully reviving it. I pour off the liquid on top and reserve it for pancake batter, then add one part flour and two parts warm, filtered water and a teaspoon of sugar and mix. I let it sit on the counter overnight, then dump it into the pan of my bread baker. For approximately 2 cups of starter I add 3 cups of flour: one each of bread, all-purpose, and whole wheat. A teaspoon of salt and sugar and a tablespoon of oil. I set the machine to bread only and let it rip. If I’m awake, I’ll check it after 4 hours. If the dough has doubled in volume, I set the machine to bake and let it go. Last night I mixed the dough then went to bed. In the morning, the dough was overflowing the pan, so I removed it and scraped the excess off the sides. I cooked it in the microwave for breakfast, then set the remainder in the pan to bake. Perfect whole wheat bread! I recycle what’s left in my sourdough container by adding a cup of filtered water and a cup of oil and a teaspoon of sugar and let it sit until it’s bubbly and foamy, then I stick it back in the fridge.

    2. Susan Reid, post author

      Hi, Charles. It’s great that you’re at such a comfortable place using your starter! Only thing I’m a little puzzled by is the oil you put in when you’re feeding it. It’s not really necessary, but if it’s useful to you for jump starting your next loaf of bread, then go to it! Susan

    1. CrudeCo

      I keep my SD starter in a sealed crock on the counter. I use oat flour and distilled water. Rotate flours each time with anient GF grain flour, then oat flour.
      Good Luck

Post a comment

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