How to Make Sourdough Starter
This guide shows exactly how to make a sourdough starter from scratch. Once you understand the process, it’s simple, and it just takes a little time and patience. If you’re troubleshooting, check out my Sourdough Bread Troubleshooting Guide or my post on maintaining a sourdough starter.
A sourdough starter
A sourdough starter is the foundation of homemade sourdough bread, English muffins, and rolls. It’s a living mixture of wild yeast and bacteria that feed on flour and water. Over time, they form a healthy colony that makes your bread rise without any commercial yeast.
When you first create a starter, you encourage these wild organisms to grow by giving them fresh flour and water every day. Once established, the wild yeast produces carbon dioxide that lifts your dough, while the natural bacteria add that signature tangy flavour.
The bacteria, mainly lactobacilli, produce lactic and acetic acids. This is what gives sourdough its sour flavour.
What you need
Every starter develops a little differently depending on your room temperature, humidity, and even the flour you use.
You’ll need:
- Flour
- Water
- A kitchen scale
It’s best to measure by weight for consistency.
Choosing the flour
Any grain-based flour can work, but unbleached all-purpose or bread flour gives the most consistent results. Rye and whole wheat can be used too, though rye tends to ferment faster because it contains more natural sugars and enzymes.
Rye flour often makes a starter look active early on, but that early bubbling can be misleading. It’s mostly bacterial activity before the yeast really establishes itself. Even if your starter looks bubbly after a day or two, it’s still too young to bake with. A white flour starter can later be used to bake whole grain or rye breads, so it’s a good all-purpose base.
Choosing the water
If your tap water is heavily chlorinated, it can slow fermentation. Filtered water, or tap water that has been boiled and cooled, works best.
Personally, I just use tap water. Mine doesn’t affect my starter or other ferments. If you’re unsure about yours, filtered water is a safe choice.
The best temperature for a sourdough starter
Yeast and bacteria grow best at around 21-26 °C (70-79 °F). If it’s too cold, the process slows right down. In very warm conditions, it will speed up, and your starter may need more frequent feeds.
Cooler temperature tip:
Pop your starter in a cooler bag with a jar of hot water beside it and close the bag to keep the warmth in. It’s a great little warm space for cold winter days. A yoghurt maker also works well. Fill it with a little bit of hot water (making sure it doesn’t touch the starter jar or it can get too hot) and set the starter jar inside so it stays gently warm.
Day-by-day sourdough starter guide
Day 1
- The following uses 30 g flour and 30 g water as a base.
Note: I always mix the flour, water, and starter in a separate bowl first, then scrape the smooth mixture into a clean jar. It keeps the jar tidy and makes level markers easy to see. Old starter sticks like glue, so this saves a lot of scrubbing.
- Mix flour and water in a bowl until combined.
- Put in a clean jar and cover with a balanced lid or cloth.
Day 2
- Tip the starter into a bowl, add 30 g flour and 30 g water, and mix until smooth. Then transfer it to a clean jar.
Day 3
- You might notice bubbles forming after day 2, but this early activity comes from bacteria, not yeast. It’s a good sign that fermentation has started, but your starter still needs more time before it’s ready to bake with.
- Pour 30 g of your starter mixture into a new bowl, feed it 30 g of flour and 30 g of water, mix well, then transfer it to a clean jar. Mark the level with a rubber band so you can see how much it rises. Discard the rest.
Days 4–10:
Repeat the same feeding each day: take 30 g of starter, feed it 30 g flour and 30 g water, and move it to a clean jar. Continue discarding the excess.
By day 4 or 5, you should see more bubbles or smell a mild tang. That’s a good sign, though it’s still not ready for bread. You can use some of the discard for recipes like pancakes or cookies.
Discarding is important. It keeps the yeast and bacteria balanced by giving them enough food each time you feed. If you keep feeding the entire jar, it compounds quickly and you’ll burn through a lot of flour.
Keep only a small portion (about 30 g) and feed that each day. Save the rest of your discard in a container for sourdough discard recipes.
Things to watch for
If your starter becomes runny, it’s usually because of the acid and alcohol produced by the bacteria and yeast. That’s normal. Just keep feeding it.
If liquid forms on top or underneath, it’s a sign your starter is hungry. Check the temperature. If it’s too hot, fermentation speeds up. Feed more often, every 12 hours if needed, until it settles.
Feeding ratio
While building your starter, use a 1:1:1 ratio which is equal parts starter, flour, and water by weight. Measuring by weight keeps your starter consistent, as water weighs more than flour.
If your starter is doubling within 6 hours by day 6 or 7, it’s nearly ready. Keep feeding 1:1:1 twice daily until it becomes strong and predictable.
Testing your starter’s strength
To check if your starter is ready to bake with, it should double after feeding it at 1:1:1 within about 4-5 hours at room temperature, 21-26 °C (70-79 °F).
You can also test it by feeding it a higher ratio, like 1:2:2 (one part starter, two parts flour, two parts water). If it can double or triple within 6 hours, it’s strong enough to raise a loaf.
If it’s still slow, keep feeding twice daily for a few more days and test again.
Maintaining your new starter
Once your starter is active and reliable, regular maintenance keeps it strong. Feed it often enough to avoid acid build-up. If you’re keeping it at room temperature, feed 2-3 times a day at 1:1:1, or twice a day at 1:2:2. In warmer weather, you may need to feed more frequently.
When it peaks (meaning it has doubled and just before it starts to fall) that’s when it’s best to use it for baking.
Once it’s well established, you can store it in the fridge. For more details, see my full guide on how to maintain a sourdough starter.
Sourdough starter troubleshooting FAQs
Chances are it was the lactobacillus bacteria in your starter forming those bubbles, and not the yeasts. Bacteria also create bubbles while they are converting sugars to lactic and acetic acid, but it’s the yeasts in the starter that will give rise to your bread. The yeast colony takes a little longer to establish itself. Be patient and keep feeding and refreshing your starter
Be patient and keep regularly feeding your starter and ensure it’s in a warm spot. If you’ve been feeding your starter for at least 6 days and it’s not bubbling you could experiment with an extra feeding, or check your water source and that it’s not hindering the starter.
This is a sign that your starter is hungry. Your starter might be fermenting a little too fast and the yeasts have run out of food. This can happen if the room your starter is in is too hot.
Check the temperature and fix it if it’s too hot before continuing. Then, carry on with the 1:1:1 feeds, but you can switch to 12 hourly feeds if it keeps splitting.
It is normal for a starter to rise, reach its peak, and collapse once it has run out of food. Once your starter can double within 5-6 hours after being fed 1:1:1, switch to 12 hourly feedings.
If it doubles within 4-5 hours with the increased feedings, try the starter activeness test.
Has the temperature changed? If it’s colder your starter will take longer to double. Have you increased the feedings? If you increase the feeds before the starter is ready, it will slow things down a bit.
If you keep up with regular discarding and feeding, in a fresh jar each time, your lactobacillus colony will thrive. As they do, the amount of lactic acid they produce will inhibit mould growth and harmful bacteria.
A contaminated sourdough starter is pretty rare. If you do see mould growing on your starter or it develops a pink, red, or orange tinge, discard it and start again.
Sourdough Starter Recipe
Ingredients
- Unbleached all-purpose flour
- Water*
Instructions
Day 1
- Combine 30 g flour and 30 g water in a bowl and mix very well until smooth. Transfer the mixture to a clean glass jar, cover it with a loose lid or cloth, and leave it in a warm spot around 21-26 °C (70-79 °F) out of direct sunlight.
Day 2
- Tip the starter into a bowl, add 30 g flour and 30 g water, and mix well until smooth. Scrape the mixture into a clean jar. Mixing in a bowl first keeps the jar tidy, since old starter sticks like glue.
Day 3
- Pour 30 g of your starter into a bowl, add 30 g of flour and 30 g of water (a 1:1:1 ratio), and mix well. Transfer it to a clean jar and discard the rest. You might notice some small bubbles by now but these come from bacteria starting to ferment, not yeast just yet.
Day 4
- Pour 30 g of the starter into a bowl, feed it 30 g of flour and 30 g of water, and mix until smooth. Transfer to a clean jar and discard the rest. By this stage, your starter might be bubbling more and smell slightly sour.
Days 5-10
- Each day, pour 30 g of the starter into a bowl, feed it 30 g of flour and 30 g of water, mix well, and transfer it to a clean jar. Discard the rest.
- If your starter is doubling easily within about 4-6 hours of feeding start feeding it 1:1:1 twice a day instead of once, or switch to a higher ratio like 1:2:2 or 1:3:3 once a day. If it’s runny each time you go to feed it, that means it’s getting too hungry between feeds. Increase the ratio or feed twice per day.
Ready for baking
- By around day 10, your starter might be ready to bake with, though sometimes it happens sooner. You’ll know it’s ready when it doubles within 4-6 hours at a 1:1:1 feeding, has a domed top, and is bubbly, spongy, and pleasantly yeasty.
- If you’re feeding it at a higher ratio, like 1:2:2 or 1:3:3, the rise will take longer, usually around 6-10 hours depending on your room temperature. That’s completely normal. The extra flour and water give the yeast more food, so the starter needs more time to ferment and reach its peak.
- If it’s still slow or inconsistent after that, keep feeding daily until it rises and falls predictably after each feed. A strong starter will show a clear rhythm and bounce back quickly after every feeding.
- If it’s still slow or inconsistent after that, keep feeding daily until it rises and falls predictably after each feed. A strong starter will show a clear rhythm and bounce back quickly after every feeding.
Notes
Troubleshooting tips
- No bubbles yet? Be patient. Early activity is usually from bacteria, not yeast. Keep feeding daily, and it will become active.
- Runny or watery starter, or grey liquid (hooch) on top: It’s hungry. Feed more often or increase the ratio (1:2:2 or 1:3:3) so it has more food.
- Strong, vinegary smell: Too much acid build-up. Give it a couple of good feeds at room temperature to rebalance it.
- Slow to rise: Check your room temperature. Starters like it warm (but not too hot), around 21–26 °C (70–79 °F).
I’ve been feeding my starter for 10 days & it has a few holes in top & smells sour but hasn’t increased in size at all in 8hrs after a 1:2:2 feed. I’m not sure what I’m doing wrong. It looks nothing like your picture on the tab for this post that has nice bubbles all the way through… should I discard & start again?
Hey, the 10 days is just a guide and some starters take longer than others.
I wouldn’t do the 1:2:2 test until my starter is doubling easily within 4-5 hours when being fed at 1:1:1.
I would wait 24 hours now and go back to discarding and feeding it 1:1:1 and wait for it to double. Once it doubles within 4-5 hours, you can switch to 12 hourly feeds of 1:1:1, and once that doubles within 4-5 hours it should be good to undergo the 1:2:2 test.
Do check that your temp for your starter is not too hot or too cold, between 21-25 degrees Celsius is good. Too hot will also slow a starter, as well as too cold.
But apart from that patience is key.
The pictured starter on my photo is what it will look like when properly active, when it can easily double, if not triple a 1:2:2 feed.
It’ll get there!
I love this article. I’ve been trying to find yeast in the shops but not having any luck. I’m definitely going to try this. You say when making your starter to use 50 g, can it be more? ie, 100g or one cup etc. Thanks Betina
It can be more but you’re doing to be discarding a fair bit so that’s why most people would prefer to keep the amount small.
If you do change the amounts, just keep the consistent with weight, 100g as opposed to 1 cup, because 1 cup flour is going to weight differently to 1 cup starter
Hi, on day 7 of the starter and it has not grew at all. It is bubbling though. Should I feed it more?
Thank you
Just continue with the 1:1:1 feeds 😊
I am curious if I absolutely have to discard of any starter? What if I just wanted to feed it again without discarding it?
Hey so if you don’t discard your starter you’re going to have to feed it a lot more to keep all those yeasts and bacteria happy. Every time you feed it more are created and the more there are the more they’ll eat.
It’s better to take a small amount each time and feed it fresh water and flour so that the organisms in there are happy and well fed.
If they go hungry they create a lot of acid and this makes a hard to work with starter.
However if you don’t want to discard it, once your starter is on day 3 or so you can use it in discard recipes.
Hope that makes sense!
I have started a white and a whole meal starter (day 3) my white is starting to bubble and rise up the jar, the brown isn’t, is that normal?
Heya yup that’s totally normal, at day 3 the bacteria and yeasts are slowly still working their way up to colonising the flour. The fact that one starter is showing activity just means more bacteria were present on that initial flour. Give it time and the wholemeal starter will catch up ☺️
Hello There,
FIRSTLY: Thank you for your wonderful recipe and instructions, like others I’ve recently been battling to find yeast (and flour), so thought now would be the perfect time to start that sourdough I’ve always wanted to try. Additionally I really appreciate a recipe from New Zealand!!!!!!
SECONDLY: Is discarding half the starter only for size and feeding purposes? In other words could I just keep feeding a compounding starter and end up with a huge starter without discarding? Or could I start small, or really small, and avoid discarding as I continue feeding? In short: to avoid discarding could I start a starter with say (for example) 12.5 g and then feed 25g, then feed 50g and so on and so on?
Thank you for your time, keep well and stay safe,
Kia Kaha.
Hey! That’s awesome you’re giving sourdough a go!
I wouldn’t start with compounding the starter as it will quickly become too big, even if starting really small.
However, you can absolutely start with really small amounts! Your suggested amounts would work very well, it’s just about staying consistent.:)
Good luck and have fun!
I put the discard in another jar and started a second jar and continue doing so, that way if one fails I have a backup , also can gift the extra to a friend
Hi, I’m about to make my starter and wanted to check that chlorinated tap water is OK (or do you use bottled water)? Also can you use a half white/half rye combination? I’ve seen this in other starter recipes.
Hey I use chlorinated tap water with no problems ☺️. You can also use half white half rye if you like. I personally like an all white flour starter because white is cheaper. Especially while it’s establishing and you’re discarding. But it’s totally a personal preference!
I have been making your sourdough for the last few months and love it…just one thing though, I had been feeding the leftover starter after the activation test with 1:2:2 and putting it in the fridge for the next loaf but it looks as though I should only be using 1:1:1…if this correct, would this be why my bread is quite holey…more like ciabatta than sourdough (but it’s still really nice, holes and all)
Thanks
Bron
Hey! The only difference the ratios make are the speed in which the starter doubles. Eg, if I feed mine 1:1:1 then it will double within 3-4 hours, whilst a 1:2:2 takes 6-8 hours.
If you feed your starter 1:1:1 and use it after 8 hours it will most likely have already peaked and fallen, and it’s passed it’s prime.
So yeah you can use whatever ratio works best with your schedule (I use a 1:3:3 when feeding my starter overnight as that takes about 10-12 hours to double).
I’m unsure that how much you’re feeding your starter has much to do with your holes bread. Big sporadic holes can be a sign of either not enough structure being built, or being underproofed. You can add a few extra folds in, or do a little slap and fold kneading before starting coil folds to add extra structure and make sure you let your bread bulk after all the folds for long enough, it needs to be 50% bigger and puffier before being shaped. A long bulk ferment will give a tighter crumb. 🙂
Thanks so much Elien… I am so grateful for your amazing explanation on this.
Do you use the ‘float test’ as well after your ‘activation test’ because mine actually tripled, but when I did the float test in water most of it stayed on top, but little strands fell to the bottom after 4 minutes so I took your suggestion to go back to steps 3 and 4… still in the process…😀Definately a challenge…
I don’t find the float test that reliable! I much rather judge it on when it doubles after a 1:2:2 feeding (it’s not enough for it to to double after a 1:1:1 feed though). If you try the 1:2:2 feed and it doubles in time it’s good to go!
About the activation test… Are you supposed to DISCARD ALL but 60-65 grams of the starter that has been fermenting for at least 5 days and add the 60 grams from that starter to a clean jar with 130 grams flour and 130 grams water?
In other words, does the “activation test starter” with 1:2:2 ratio become the new starter if it doubles within the 6-8 period of time? And if it does not double in size within the 6-8 hour period, do you then continue feeding the activation test jar the 1:1:1 ratio until it is ready, or do you discard that jar entirely and continue on with steps 3 & 4 from your sourdough starter recipe with the original?
This is the only point I am not exactly clear on, and would really appreciate your
advise.
Thank you in advance,
Melissa
Hey Melissa, you can actually do either but I find it easier to use the ‘activation starter test’ as the new starter and if it doesn’t double, go back to feeding that test 1:1:1 until it’s ready 😊
Excellent instructions but please tell me two things:
1. whilst maintaining the starter, when I feed it and put it in the fridge, do I first let it rise and then put it in the fridge or just feed it and immediately put it in fridge?
2. On your You Tube video for ‘Easy No Knead Sourdough’ you don’t cover the dough at all whilst doing the 30 minute interval folding? Is that correct?
Thank you
Hey you can feed it and pop it straight back in the fridge. On my video I don’t show it but I actually place a plate over that pie dish to cover the dough. If I see it drying out I’ll place a damp tea towel over instead.
Sometimes i forgot to cover it completely though and it’s still fine!
Thank you for the directions. I’ve watched several “Bake With Jack” video clips and he has one called “The Scrapings Method”
https://www.youtube.com/watch?v=Uj6YpNCUYYQ&t=8s
that sounds promising to avoid throwing any away.
Cool 🙂 I myself rarely throw starter away as we use the discard in so many recipes!
I am I the process of starting my starter. I have had lots of people ask for a starter when my starter is ready. Do I give the discard away as a new starter or is there another process for doing this?
Heya, I would wait to give it to others until it’s at least doubling within 5-6 hours. Otherwise they’ll have to also feed and discard for a few days until it’s ready.
Once it’s doubling easily, the next time you discard, you could take that discard and feed it and divide that up to give away 😊
Hello! Thank you for your directions! It’s about Day 10 for me and I just did the activeness test! It seemed like my starter barely grew, but when I removed the lid from my mason jar a bunch of gas released from the jar and my starter grew all the way up to the top of the jar right then and there in less than a second! Does that count as doubling in size? Also, I’m not sure why that happened. Maybe I’m closing the lid too tightly?
Heya the jar shouldn’t be sealed with a lid. Try the test again but cover it with a tea towel or cloth