What is sourdough starter and how do you make one? A sourdough starter is a natural leaven made from flour and water that ferments over time. Wild yeast and beneficial bacteria naturally present in flour and your environment colonize the mixture, producing the bubbles that make bread rise and the acids that give sourdough its signature tangy flavor. This is why we call it sourdough. It’s tangy and does amazing wonderful things to baked goods.
It’s extremely simple to make sourdough starter from scratch. All you need is flour, water and time. Follow the simple process in this recipe to create a healthy sourdough starter that will grow and bubble as it gets stronger. Soon you’ll be creating fantastic breads and an endless amount of recipes that use up sourdough starter in the most delicious ways.
What Is a Sourdough Starter?
A sourdough starter is a natural leaven made from flour + water that ferments over time. Wild yeast and beneficial bacteria naturally present in flour and in your home environment natural yeasts populate the mixture, creating the bubbles (carbon dioxide) that help bread rise and the acids that create sourdough’s signature flavor.
If you’ve been wondering “what is sourdough starter and how do you make one?”—you’re in the right place. This guide shows you how to make a wild sourdough starter from scratch, how to maintain it, and how to get it ready for baking.
Start here if you’re new: This is the foundational starter guide for our sourdough baking. You’ll find all our sourdough tips, recipes and trouble shooter post here in the Sourdough Hub when you need them.
What You Need to Make Sourdough Starter From Scratch
You only need a few basic things, but getting the basics right saves days of frustration.
Flour options (and when to use whole wheat/rye)
Most beginners do best starting with unbleached all-purpose flour because it’s affordable and consistent. Whole wheat or rye can speed activity in a sluggish starter because they contain more enzymes and nutrients, but they can also make the early days feel “messier” (more smell, faster fermentation swings).
Beginner tip: If your starter seems sleepy around Day 3–5, do one or two feedings with whole wheat or rye to boost activity, then return to all-purpose.
Water + temperature tips
Use non-chlorinated water, (filtered is fine). Starters are noticeably slower in cool kitchens. Aim for a “warmish” spot—around typical room temp.
Jar + scale tips (why grams matter)
A clear jar makes it easy to track rise and fall. A kitchen scale makes your starter much more consistent because flour measured in cups can vary a lot depending on how it’s scooped.
How to Make Sourdough Starter
This is a slow process. It needs to be. Be patient and you will be well rewarded. And don’t forget I’m right here if you need help. Just ask in the comment section and I’ll reply. For the details, jump down to our recipe card. here is the general process and some tips.
Day 1
Mix flour and water until smooth (thick batter). Cover loosely so gas can escape but the surface doesn’t dry out.
Days 2–4
Discarding and feeding feels wasteful, but it’s part of building a healthy culture. Discarding:
- reduces excess acidity
- keeps the yeast/bacteria balanced
- gives the fresh flour something to ferment
What you’re looking for: small bubbles, light expansion, and a shifting smell (from “wet flour” to slightly tangy).
Many starters show a burst of bubbling around days 2–3 and then suddenly appear to “die.” This is normal. Early bacterial activity creates temporary bubbles before the yeast population stabilizes. The starter may look quiet for a day or two while the microbial balance settles. Keep feeding it regularly and activity will return.
Days 5–7
This is where many beginners get confused because activity can look inconsistent. A starter may bubble vigorously one day and slow down the next. That’s normal while the culture stabilizes.
What you’re looking for by the end of this window:
- visible bubbles throughout the starter
- a noticeable rise after feeding
- a tangy aroma (not rotten)
Days 8–14 (and what “ready” really means)
On average it takes about two weeks to build a starter strong enough to bake with. That’s a decent estimate, but what matters most is behavior, not the calendar.
By this stage, a usable starter typically:
- rises to double its size and falls predictably
- shows strong bubbles
- doubles after feeding within a reasonable window at room temp
When Your Starter Is Ready to Bake
What “doubling” means
A starter is “ready” when it reliably rises after feeding and becomes airy enough to support dough fermentation. The simplest test is consistency. Feed it, mark the jar, and watch for a predictable rise and fall pattern. When you can feed your starter and it reliably doubles in size in 8 to 12 hours or less, it is strong enough to bake bread.
Why the float test is optional:
I use the float test as the final test for baking readiness. It almost never fails me. However, while
the float test is helpful, it’s not always reliable because texture and hydration affect buoyancy. This is especially true for young starters. They need to be doubling reliably.
A starter can sink and still be ready and it can float briefly and still be too weak to raise some breads well. The float test can be a helpful quick check, but it’s not foolproof.
Better readiness signal: Hydration and texture affect whether the starter floats. But floating is not as significant as the consistent rising and falling after feeding. That’s the signal to depend on.
Consistent rise after feedings + a lively, bubbly structure are your best indicator that your starter is ready to raise bread. Again even this is not fail safe. Watch your starter as it rises and falls after feeding. When the starter is at the top of its growth it is strongest and ready to use. These are your leading indicators for a healthy, strong starter.
Feed and Maintain a Sourdough Starter
Once the starter is active, maintenance becomes simple.
Counter vs fridge schedule
- If you bake often: keep it at room temp and feed regularly. But note; a warm young starter needs more feeding or it will quickly die. So keep an eye on it.
- If you bake occasionally: store in the fridge and feed weekly (then do 1–2 room-temp feedings before baking). This is what I do. My starter needs much less attention when I store it in the fridge and remember to feed it weekly. But watch your starter after re-feeding if it’s been stored in the fridge awhile. They can weaken and need more than one feeding to bake good bread. Make sure it is doubling reliably with lots of action before using for baking.
Feeding ratios For 100% hydration starter:
This starter is a 100% hydration starter, meaning equal weights of flour and water and starter when you feed it. This is pretty standard and most bread will rise well with it, so that is how we will maintain your starter. The next step is feeding and maintaining it.
- maintenance of this starter and preparing it for baking bread requires you keep it fed and strong.
- Before Baking with your starter feed it 1:1:1. This means equal parts flour, water and starter are mixed into a container and allowed to double in size before baking.
Read our complete post on How to properly feed and maintain your starter here.
How to prep starter for baking
Before mixing dough, feed your starter so it’s active and ready. Many bakers do this the night before a bake. Your “prepare starter for baking” section is useful; it simply needs to live under this heading so it’s not buried in Notes.
Our Long Cold-Rise, No-Knead Artisan Sourdough Method is very simple and achievable one you get your starter strong and keep it well maintained.
Troubleshooting: Slow Starter, No Bubbles, Bad Smells
Starters behave differently depending on flour type, temperature, and feeding schedule. Small adjustments usually solve most problems.
If your starter isn’t bubbling or rising as expected, don’t panic. The usual causes are:
- Temperature: cool kitchens slow fermentation dramatically
- Flour: bleached/low-protein flours can be sluggish
- Water: heavily chlorinated water can inhibit activity
- Feeding pattern: inconsistent feeding or ratios
Quick fixes:
- move starter to a warmer spot
- do 1–2 feedings with whole wheat or rye
- feed at the same time daily for a few days
What to Do With Sourdough Discard
Discard is simply the portion you remove during feedings. In the early days, discard is usually not strong enough to raise bread, but it is excellent for no-rise discard recipes like waffles, pancakes, crackers, and more.
As you feed your sourdough starter, you’ll naturally create discard. Discard is simply unfed starter and does not need to be wasted.
While discard is usually not strong enough to raise bread, it works beautifully in recipes like those listed below. But be sure to search this blog for more discard recipes. We have many ways to use sourdough discard up.
Here are a few easy ways to use sourdough discard to get you started:
- Discard Sourdough pancakes
- Sourdough waffles
- Discard Sourdough crackers
- sourdough pizza crust
- Sourdough Discard Donuts
Search our sourdough section to find recipes you’ll enjoy that make use of the weak, discarded starter.
As you get further into the process your starter will strengthen and so will the discard. This gives you even more sourdough recipe options for sourdough discard.
A whole host of other baked good are in your future. It all begins here with a good sourdough starter. Here is your printable recipe card.
Sourdough Starter Recipe
A wild yeast sourdough starter collects the wild local yeast always found in your environment and flour and makes your own unique and flavorful starter. Once it gets bubbly you're all set to make the best sourdough recipes!
Ingredients
- 100 grams flour (1 cup of flour-4 ounces of flour)* see notes
- 100 grams lukewarm water, (1/2 Cup or 4 ounces of water)- avoid chlorinated tap water (Use chemical free bottled water if necessary)
Instructions
Tips for making a sourdough starter:
- Use a quart glass jar or a large plastic container. You will need a jar lid or Saran Wrap with a rubber band to tighten it over a jar. The plastic container should have a good air tight lid. You can also cover the container with a dampened tea towel.
- During the process of making the starter gases will expel from the container. Keep the lids loose enough to vent the gases but you need to cover the container or the starter will dry out too much.
- This is a 100% hydration starter.. By weight, you add equal amounts of water and flour. For best results please use a kitchen scale to weigh your ingredients for your starter. This is not strictly necessary for success, but most exact. You need to use the same ratio of flour to water for best results.
Day One:
- Combine the Flour and water in the container and mix well.
- Cover the container and allow to sit in a warm place (around 70 degrees F).
Day Two:
- Discard one half of your starter (about a 1/2 Cup).
- Feed your starter 100 grams of flour to 100 grams of warm water.
- Mix it together, cover and let sit 24 hours.
Day Three:
- You should see small bubbles appearing by now and the concoction will smell aromatic with a slight fruity aroma. This means wild yeast have found your mixture and are already working their magic.
- Feed your starter twice -12 hours apart- (or close as you can)
For EACH feeding: - Stir down the starter.
- Remove all but 100 grams of starter and discard it.
- Feed your starter 100 grams of flour and 100 grams of water.
- Cover loosely and let sit until next feeding.
Day Four:
- Discard all but 100 grams of starter and repeat your feeding of 100 grams each of flour and water.
- Stir, cover and let sit in a warm place.
Day Five to Seven:
By now you should see a bubbly starter with some action. The fermentation process is getting a good start.
Repeat feeding and discarding like day four.
- You should see the starter rising and falling about an inch on the jar as the day progresses.
- This means you have enough yeast they are visibly going through their lifecycle of eating and digesting the flour and water you feed them.
Day Eight to Fourteen:
- Do a dailly (or twice daily if your starter is not bubbling) feeding this way.
- Discard all but 100 grams of starter and repeat your feeding of 100 grams each of flour and water.
- Cover and let it sit.
- By day 14 your starter should double in size 8 to 12 hours after feeding at room temperature.
Tips to help Activate a Slow Starter:
If you do NOT see this rising and falling and bubbling action as expected. Try these tips:
- Repeat feeding every twelve hours as instructed in step four until your starter gets active.
- Try a warmer room and leave the container uncovered a bit to capture more yeasts.
- If you get to day seven and see no small bubbles forming in your jar try using whole wheat or rye flour for a few feedings. High enzyme content in these whole grain flours will help boost the starter and get it going.
Notes
*The ingredients listed are for one feeding. Repeat this process daily or twice daily as instructed. A ten pound bag of flour will get you through the process with flour to spare.
Day 5-7 look for these things:
The starter should be bubbled and webbed all the way through. It should have a distinct smell. Sort of sour and vinegary with a bit of alcohol headiness. It will get looser as it matures and the yeast eats the flour faster.
Continue to feed the starter daily to keep strengthening it. somewhere between day 7 and day 14 it should be getting strong enough to raise bread. The bread will not raise as well as it will after 30 days of strengthening but you are at the gates of success.
The final test of a starter: Does it double after feeding?
Once your started is strong it should reliably double in height in a straight sided container 8 to 12 hours after feeding. Once it has risen to it height its ready to bake.
The Float Test:
While not as reliable as the doubling I use it before I bake and always have good results. Put a teaspoon of starter into a glass of room temperature water. If it floats, it's ready to use. If it sinks or almost floats; Feed it again and give it another few hours and retest. It may take up to a day.
Maintain your starter:
Discard half of the starter everyday now and continue feeding it for 30 days. This will strengthen it and help you maintain an active starter. After the starter is reliably rising your breads well, you can reduce feedings to weekly. Just be sure to feed it 1:1:1 proportions before baking. We cover prepping your starter for baking in this post.
TO PREPARE A STARTER FOR BAKING:
- Once the starter is active and bubbling feed it this way to ready a starter for baking bread.
- You need EQUAL parts starter, High protein bread flour and water. Here's how I prep my starter.
- You can use smaller or larger amounts but keep the proportions 1:1:1.
- 8 to 12 hours before baking:
- In a quart sized bowl Mix together 100 grams starter (room temperature), 100 grams flour, 100 grams water (lukewarm)
- Loosely cover the bowl and set it in a warm place (70 degrees F).
- In 4 to 8 hours the starter should double in size and float in water at least 15 to 20 seconds without starting to dissolve.
Nutrition Information
Yield
16Serving Size
1Amount Per Serving Calories 23Total Fat 0gSaturated Fat 0gTrans Fat 0gUnsaturated Fat 0gCholesterol 0mgSodium 1mgCarbohydrates 5gFiber 0gSugar 0gProtein 1g
Next Step: Bake!
Once your starter is active, you’re ready to bake. If you’re new, start with one dependable loaf that teaches the method clearly. Our Beginner Artisan Sourdough bread Recipe / Tartine-style artisan loaf is a complete run through, step by step, of how to make a delicious, crusty loaf of sourdough with a creamy open crumb. It’s one of our most popular posts with hundreds of satisfied bakers who come back to make it time after time.
Here are some of our simple sourdough bread recipes. This is just a taste of what you can do with your fully active sourdough starter.
Most of the sourdough breads on this blog use this same long cold rise, no knead method. So once you have it mastered, you can literally bake SO many different bread recipes. Our Sourdough Soft Sandwich Bread is also highly acclaimed by hundreds of bakers. Sasha, our master baker offered this recipe years ago along with her Milk and Honey Sourdough Sandwich Loaf and her Soft Cinnamon Raisin Bread.
Further Reading:
Note: Commercial yeast—often called baker’s yeast or domestic yeast—is the packaged yeast sold in grocery stores as active dry or instant yeast. It is a single cultivated strain of yeast, Saccharomyces cerevisiae, bred to produce fast, reliable rises in bread dough. While some sourdough recipes add a small amount of commercial yeast to speed up fermentation, I prefer not to use it in sourdough baking.
A traditional sourdough starter relies entirely on wild yeast and naturally occurring lactic acid bacteria living in the flour and environment. These microorganisms work together slowly to ferment the dough, creating the complex flavor, structure, and digestibility that make sourdough unique. For that reason, the starter method in this guide and our sourdough recipes use only flour and water to develop a true wild sourdough culture and fermentation process.
This simple wild yeast starter recipe gives you the basic starter you need to bake elegant sourdough loaves at home with the complex flavors that natural fermentation creates.
Flours Best For Sourdough Starter?
Any flour with a gluten content will ferment and make a sourdough starter. Unbleached All purpose flours work fine for building a new starter. They provide consistent results and are cheaper. However, You can also build entire starters on rye, einkorn, or whole wheat flours.
If your starter is weak and needs a boost, use a whole grain flour or rye flour for a feeding or two.
You can change the flour you use to feed your starter. As we discussed above this is often desirable when your starter is weak and needs a boost of enzyme action from whole wheat or rye to wake it up.
Can You make Sourdough Starter With a Gluten Free Flour?
Sourdough starters can be made gluten free. You will need a proper gluten free flour for this purpose. King Arthur Flours has the flour and the recipe for gluten free sourdough starter. If you want more information on sourdough flours and their properties read our sourdough flour types guide.
Any good quality flour with a protein content of 12 % or better will work well in most sourdough bread recipes with a strong starter.
Sourdough bread baking is very simple. But the subject of sourdough is deeply complex due to the science and history of this ancient method of bread baking.
Do Sourdough Starters Get Better with Age?
Sourdough starters do get better with age. If they are well maintained starters get stronger and provide your baked goods with better structure and flavor as they age.
Heirloom sourdough starters are passed down through the generations in some families. Some starters are hundreds of years old and still baking good bread today.
You are creating a live growing, long term kitchen companion when you make a sourdough starter. Some people name their starters and enjoy playing around with adding different ingredients to ferment in with them. Apples and potato water are both popular.
Can you Dry Out Sourdough Starter?
Yes! Sourdough starter dries out in the air quickly. You can spread the starter in a thin layer on parchment paper and let it dry. You won’t need much. Even a couple of tablespoons of dried starter can be revived into useable starter. Read Our Complete guide to drying, storing and reviving your starter in this post.
Can you Buy Ready Made Sourdough Starters?
You can buy ready made dried starters online from Etsy shops or Our baker friend Sasha linked below. These are fun to explore since they can be made in so many ways with ingredients like potato water and apple peelings.
If you are really lucky, someone will give you a piece of their starter to get you started. If it is already strong and active you just feed it and bake. Ask around your friend groups. You may be surprised who has a sourdough starter they will share or sell cheap.
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Recent Posts:
- Autolyse vs Fermentolyse vs Saltolyse: Which Sourdough Mixing Method Should You Use?
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If you are looking to buy sourdough starter rather than build your own CONTACT SASHA HUNTER. She sells her well established Apple Jack starter all over the U.S. It makes great bread.
If you are looking for bread info and inspiration check out Karen Kers Bread Bakers and Artisan Bakers FB group
King Arthur website is full of AMAZING information and tips on all kinds of baking, including sourdough
Further Reading:
- The Bread Baker’s Apprentice by Peter Reinhart
- The NEW Healthy Bread in five minutes a day by Jeff Hertzberg & Zoe Francois
- Artisan Pizza and Flatbread in Five minutes a day By J Hertzberg & Zoe Francois
- Tartine Bread by Chad Robertson
- Tartine Book 3 By Chad Robertson
RESOURCES:
Lynn
Wednesday 24th of April 2024
I cannot eat wheat but can eat spelt. Can I use spelt or other flours in a sandwich loaf? And if so what flours would you recommend?
Diane
Wednesday 24th of April 2024
Hi Lynn,Yes, you can definitely use spelt or other alternative flours in a sandwich loaf if you cannot eat wheat. You can experiment with rice flour, almond flour, oat flour, chickpea flour, or a gluten-free flour blend. You might try blending some spelt into our sourdough Oat loaf recipe. If you enjoy almond flour start with that in this recipe. Ive had good luck with almond flour in baking but I'm not sure it will give you a good rise.
When substituting alternative flours in a sandwich loaf recipe, keep in mind you may need to adjust the quantities and other ingredients accordingly. For example, some gluten-free flours require binders like xanthan gum or guar gum to help the bread rise and hold together.
Im not a gluten free bread baker so I hope you have the experience to play around with these ideas. If you do develop a good loaf please let us know. Have a great day!
Vickie
Wednesday 7th of December 2022
Where should the starter be kept? In the fridge or counter? I live in a hot/humid climate (I never bake at all in the summer) and I have been keeping it in the fridge, but it’s not bubbling like it was in the beginning. I’m feeding it 1:1 (1/4cup) usually everyday right now and haven’t been discarding anything. When it gets to be to much starter, I make waffles and freeze. Also, I don’t want to have to bake bread too often, so what would be the best amounts to feed it? Discard how often? The maintenance of the starter is confusing to me.
Diane
Wednesday 7th of December 2022
Hi Vickie, If your starter floats in water after feeding it in 1:1:1 proportions, it should be strong enough to bake bread even if the bubbles are small. I keep my starter in the fridge unless I'm getting it ready for bread baking.if you put starter on the counter all the time, it will need a LOT of feedings to keep it from getting too hungry in a warm climate so fridge is best. I also do not bake weekly. I do try to feed my starter every week and use the discard for a recipe of some kind. Lately sourdough pizza is my 'go to' way to use up sourdough discard. Once your starter gets strong enough to bake bread with a decent amount of rise you don't need to be feeding it daily. If you want to hold your starter in the fridge without baking for a while try feeding it with 2 times the amount of flour to starter and water. This will give you a very thick batch with plenty of food to hold it for awhile. It will eventually lose strength if left unfed for several weeks to a month. Then you will feed it 1:1:1 again and let it sit on the counter 8 to 12 hours to strengthen it. You may have to repeat this again the next day if your starter is very weak. I hope this helps! Happy Holidays!
Sue
Monday 2nd of May 2022
Hello! I must be doing something wrong or misunderstanding something! I am in the process of making my first batch right now. So far, so good, except after I measured out the 200 grams of starter, I only had 60 grams left. Does this sound right? If so, do I feed it 60 grams of flour and water to maintain it? In that case, how do I grow it so that I have a larger amount of starter?
Sue
Wednesday 4th of May 2022
@Diane, I’ve read all of the above (and the bread I made yesterday came out wonderfully!) but let me rephrase my question if you don’t mind answering me again! If my starter doubles after following the instructions to balance it with 100 grams of each, and I then use it for my recipe, I have very little left. When I balance the starter in the last feeding before baking, can I use 200 grams of each instead of 100 so that I have more left to maintain my starter after I remove the amount needed for my recipe? Hope that makes sense…I don’t want to run out!
Diane
Monday 2nd of May 2022
Hi Sue, What you are telling me is perfectly correct. No worries. Yes, do feed and stir the remaining starter. Watch the video on the process too for further help with growing your own starter. I don't know which day of the process you are on. Let me say if you follow the recipe exactly it will normally work as stated. I'm sorry if it is confusing you. Your kitchen temperatures, the amount of yeasts in the flour (completely unpredictable) and your kitchen will all come into play on how this works out for you. But it will work. Wild yeast is everywhere. Your starter may not grow as fast initially and that is probably throwing you off. Just keep feeding and discarding until it gets stronger and begins to grow during feedings. All the best! PS: For more on feeding and maintaining a starter this post will help you</a
Pat Martin
Wednesday 3rd of March 2021
Hi Diane, I had a sourdough starter years ago that I got from I don’t know where. I was brand new to bread baking even, but adventurous. I had it literally for years but it finally passed away from months of neglect. I had tried again but with limited success. I even ordered one from King Arthur. Now that I’m retired with more time, I’m trying again. This time I decided to some of the kombucha tea I’m experimenting with. It took right off as you can imagine. I’ve been playing with it and feeding it daily, all be it not the same time everyday for about 2 weeks now. It’s bubbly, smells great but does not float, and doesn’t seem to double in volume. I Made a test loaf that was pretty good, I’ve made delicious English muffins and pancakes with the discard but I tried your raisin cinnamon bread with freshly fed starter, after about 3-4 hours and it doesn’t rise well and has no oven rise. 😩. Any suggestions?
Diane
Wednesday 3rd of March 2021
Hi Pat, How Interesting that you tried it with kombucha! I think you're halfway there. Try feeding the starter 1:1:1 (equal amounts of flour, starter and water)the night before you try to bake bread with it next time.
I just wrote a whole post on how to maintain, feed and balance your starter for bread baking. This is a common problem. Once we get a lively starter it is important to feed it for the intended purpose. Starters tend to go out of balance so this is how I always feed when I'm getting ready for bread baking.
Let me know how it goes for you! All the best.
Monica
Sunday 26th of July 2020
I think a common theme with people asking about the float test, and people saying theirs doesn't float is that it should be mentioned that the float test should be done when the starter is at it's "peak" after feeding. I didn't realize that when I first started and kept testing mine just before I'd feed it, I went nearly 2 weeks of feeding and testing at the wrong time. It matters a lot that it's at its highest and not just any old time. Just the same as when it's used, it needs to have been fed recently for most recipes.
Diane
Sunday 26th of July 2020
Hi Monica, Thanks for adding this tips for our bakers. Have a great weekend!