How to Make Sourdough Starter From Scratch: Step-by-Step Guide

Learn how to make a sourdough starter from scratch with this easy, straightforward, step-by-step guide that’s perfect for beginners! With just flour, water, and some patience, you’ll have a bubbly, active sourdough starter as I show you the simple day by day breakdown of how to make one from scratch. By the end, you’ll be ready to bake rustic homemade sourdough bread, fruit and nut sourdough, pumpkin sourdough… everything sourdough!

If you’re new to the world of sourdough, it can be a bit intimidating! And there is so much information out there on sourdough.

But if you’ve been following along my blog, you’ll know that I’ve spent (at time of writing) 12 years studying and teaching philosophy, so I know a thing or two about making complex things simple! And that’s why this sourdough starter recipe is straightforward, easy, and foolproof. You’ll be baking your own fresh loaf of homemade sourdough bread in no time!

After all, people have been baking sourdough bread for literally thousands of years. And all without fancy equipment, a gazillion types of flour, or complicated processes. So it’s baffling that it’s seen as so complicated these days!

That’s why this recipe for how to make a sourdough starter from scratch gives you an easy, step-by-step guide, broken down into a daily sourdough starter schedule. Spoiler! You only need to spend about 2 minutes a day to get a sourdough starter going!

What is a Sourdough Starter?

A sourdough starter is a live, active, fermented culture of flour and water, which feeds off of wild yeast and natural lactic acid bacteria. Because of this lacto-fermentation, carbon dioxide is produced in a healthy starter, which creates little gas bubbles. A bubbly starter is an active, healthy starter! But these carbon dioxide bubbles are actually what leavens our sourdough bread (makes it rise), and gives it that lovely characteristic tangy flavour.

Why Make Sourdough Starter? (Health Benefits of Sourdough)

Commercial yeast was made available in the 1800s to leaven bread. But before this, people were baking sourdough bread for thousands of years using sourdough starter to leaven their bread. So it’s an ancient, traditional food, that’s actually more nutritious than bread made with yeast.

That’s because most grains and legumes, including wheat, contain compounds called anti-nutrients, like phytic acid (phytates). These compounds make it difficult for our bodies to absorb minerals. But by fermenting flour like we do in sourdough starter, this phytic acid is broken down, making the nutrients in sourdough bread more bioavailable. This means our bodies can more easily absorb the minerals!

Ingredients Needed for Sourdough Starter From Scratch

All you need is flour and water for a sourdough starter! And a jar of course.

Many recipes will tell you to use whole wheat flour, rye flour, or some kind of ancient grain. Some will tell you to buy a specific kind of bread flour, and some recipes call for pineapple juice! I am here to tell you that any plain flour from the supermarket will do. I use all-purpose, plain organic flour from either Coles or Woolies, so I have organic sourdough starter and can therefore make organic sourdough bread!

But I have had sourdough starters in the past with your everyday, basic, plain flour. I am certain that for the past few thousands years of baking sourdough bread, people have been using whatever flour was on hand. It doesn’t need to be complicated. Of course, you may choose different kinds of flours for different health benefits, and for different results for your starter, but for getting a basic starter going, any will work!

As for water, make sure you use filtered, non-chlorinated water as chlorine can hinder your sourdough starter.

How to Make a Sourdough Starter From Scratch

Here’s the short version. Mix equal parts (by weight) water and flour in a jar, and pop the lid on loosely. Leave it out on the counter in a warm spot. From day 3 onward, each day, discard half, and feed with equal parts (by weight) water and flour again and mix. Repeat everyday and from anywhere between day 14 to day 21 (sometimes longer!) you’ll have a starter that doubles in size within 4-8 hours of feeding. This means it bubbly, active, and ready to bake sourdough bread with!

But I promised you a step-by-step guide, so here is my daily schedule for a sourdough starter from scratch, with exactly what to do each day, and what you can expect to see in your starter jar each day.

Day 1

Day 1: mix 50g flour and 50g water. Total sourdough starter weight in jar: 100g.

Mix equal parts (by weight) flour and water in a jar. For this recipe, I use 50g of flour, and 50g water. This is the ratio of flour and water you will feed your starter with every day. Make sure to use lukewarm water (not cold, and not hot!).

Just make sure you mix well so there are no dry lumps of flour, and scrape down the edges so everything is level. It will just be a thick paste at this point, like this.

Place the lid on loosely, and leave out on your counter, in a warm spot of your kitchen for 24 hours. Alternatively, cover with a cheese cloth or tea towel.

Note: It’s important the lid is on loosely. You want some gas to escape without letting too much air into your sourdough starter jar. If using a screw-on lid like I do, just place the lid on, do a half-turn and leave it. If placing in the fridge for long-term storage or during maintenance, then it’s fine to screw it on completely!

Day 2

Day 2: Nothing, just stir well! Total sourdough starter weight in jar: 100g.

Nothing much will have happened on day 2! Just stir your sourdough starter to oxygenate the mixture and help fermenation begin. It might have a very faint yeast smell, or be slightly stretchy and elastic.

It also may have a couple of small bubbles here and there. And if not, this is totally fine. Any bubbles or odour will likely be caused by bad bacteria being killed off at this stage, not by yeast.

Day 3

Day 3: Discard 50g of starter (half the starter), keep 50g in jar. Then feed with 50g flour and 50g water. Total sourdough starter weight in jar: 150g.

On day 3, you will likely have a very bubbly, airy mixture! This is very common, and is called a ‘false rise’. It’s caused by a flurry of some yeast, but mostly bacteria multiplying and being killed off. This process produces gas, which give an aerated texture to your sourdough starter. It is not ready to bake with yet.

It might have a very faint yeast smell, or smell like dirty socks, or vinegar, or just generally unpleasant. All of these are normal!

On day 3 of your sourdough starter from scratch, start the daily discard and feed process! Pour out half (50g) of the starter (discard) into a jar.

Tip: Pour your sourdough discard into an airtight container to place into the fridge. Each day, you can keep adding to it. You absolutely do not have to throw sourdough discard away! It’s perfect for baking into sourdough flatbread, sourdough pancakes, or sourdough pizza – the list goes on!

Then feed the remaining 50g of your starter with 50g flour and 50g water. Mix the flour and water into your starter, and stir well. Make sure to scrape down the sides of the jar. Loosely cover, and leave out at room temperature.

This ratio of 1:1:1 (50g:50g:50g) starter to flour to water is the perfect ratio for building a basic sourdough starter.

What’s that Dark/Clear Liquid on Top of My Sourdough Starter?

By this point, you might have a clear, or dark liquid forming on top of your starter or halfway in the jar. This is called ‘hooch’ and it is simply a sign that your starter is hungry! It’s a completely harmless alcohol by-product of fermentation. I usually just stir it back in. But you can pour it out if you prefer.

The only time to be concerned is if you see pink or orange spots or streaks, or mold forming. In that case, throw the whole starter out and begin again with sterile equipment.

It’s always best to use clean equipment when making a sourdough starter from scratch, although sometimes the flour is contaminated, and sometimes it’s just bad luck!

This is an example of harmful pink and orange bacteria in a starter, which was thrown out.

Day 4

Day 4: Discard 100g starter, keep 50g in jar. Then feed with 50g flour and 50g water. Total sourdough starter weight in jar: 150g.

On day 4, your sourdough starter may have a few bubbles, and some hooch forming. You can stir it back in! It also might have a slight yeasty smell which is a good sign that fermentation is happening!

Discard 100g of your starter, leaving 50g behind in the jar.

This allows us to stick to the 1:1:1 (50g:50g:50g) ratio of starter to flour to water. And that’s why we discard more than we did on day 3! It makes sure the yeast have enough food to feed on, and prevents your sourdough starter from becoming acidic, and from the volume growing exponentially.

Then feed your sourdough starter with 50g flour, and 50g water.

Mix, making sure to scrape down the sides of the jar. Cover loosely and leave out. And from this point on, there’s no extra math involved! You just repeat the process of discarding 100g, (keeping 50g of starter) then feeding with 50g flour and 50g water each day.

Day 5

Day 5: Discard 100g starter, keep 50g in jar. Then feed with 50g flour and 50g water. Total sourdough starter weight in jar: 150g.

Day 5 will be more or less the same as Day 4. If there is any hooch, stir it back in, and any yeasty smell is a good sign! Slight bubbles are also a good sign, but don’t worry if you don’t see them. This is the phase where yeast and beneficial bacteria are still building up. Many people will see this is a sign that their sourdough starter is dead – it’s not! It’s just dormant.

Day 6

Day 6: Discard 100g starter, keep 50g in jar. Then feed with 50g flour and 50g water. Total sourdough starter weight in jar: 150g.

On day 6, you may or may not see your sourdough starter rise. It won’t necessarily double, (although it might!). But it can also grow up to 50% in volume, which is a good sign of activity. It all depends on a few factors, (temperature, flour type, environment). But you may see more bubbles forming on top, and notice a vinegar or yeasty smell as the yeast and good bacteria multiply.

Day 7

Day 7: Discard 100g starter, keep 50g in jar. Then feed with 50g flour and 50g water. Total sourdough starter weight in jar: 150g.

Much the same as day 6! Your sourdough starter will likely be growing anywhere from 50% of its volume to doubing in size. It may have a strong acidic, tangy, or even a yeasty smell and be quite bubbly at the 7 day mark. When you give it a stir, it should have a mousse-like, bubbly texture, which is a fantastic sign that the yeast and good bacteria have taken over and there’s plenty of activity going on in that jar.

Note: Growth at this stage is a good sign. But it doesn’t mean your starter is ready to bake with. It’s definitely not mature enough to make a whole loaf of sourdough bread rise. If you do bake with it, your sourdough loaves will likely turn out gummy and dense. (Not the end of the world – you can always turn them into sourdough croutons or sourdough breadcrumbs!). Making a sourdough starter from scratch requires patience, but it’s only ready to bake sourdough bread with when it reliably, consistently doubles within 4-8 hours of feeding for a few consecutive days.

Day 8

Day 8: Discard 100g starter, keep 50g in jar. Then feed with 50g flour and 50g water. Total sourdough starter weight in jar: 150g.

Pretty similar to day 7! On day 8, your sourdough will likely have risen by at least 50% (or perhaps even doubled), and will be very bubbly with a mousse-like texture.

It might even begin to smell like nail polish remover. This just means your starter is hungry for its next feed and the yeast has eaten all its food and has produced an acetone by-product. It’s actually pretty common with new starters. Nothing to worry about! It’s a sign to start considering increasing your feeding frequency.

Day 9

Day 9: Discard 100g starter, keep 50g in jar. Then feed with 50g flour and 50g water. Total sourdough starter weight in jar: 150g.

Your starter will likely be very bubbly by this point, have a mousse-like texture, and almost doubled in size. And if it didn’t smell like nail polish remover on day 8, then it likely will today (and will be quite noticeable!). This is your sign to start feeding twice a day (every 12 hours) instead of once every 24 hours. The nail polish remover smell indicates the yeast has eaten all its food, and is producing acetone by-products. In other words, your starter is hungry!

Day 10

Day 10: Feed twice daily! Discard 100g starter, keep 50g in jar. Then feed with 50g flour and 50g water. Wait 12 hours (not 24) and repeat. Total sourdough starter weight in jar: 150g.

At the start of day 10, your starter will still be very bubbly with a mousse-like texture. If your starter smells strongly of nail polish remover, it’s time to do twice daily feedings, so every 12 hours. The nail polish remover smell is an acetone by-product of the yeast in your sourdough starter eating through all is food. So it’s hungry!

Feed it as per normal, then wait roughly 12 hours for it to double in size, and repeat the exact same process, with the exact same ratios.

Tip: Place a rubber band on the outside of your sourdough starter jar to mark the level it’s at once you feed it. This way you’ll easily be able to tell when it has doubled!

By the 12 hour mark, once you do your second feed of the day, your sourdough starter will probably almost have doubled in size. This is a great sign the hungry yeast have gotten a lovely big meal and have eaten through their food!

Why Do Twice Daily Feedings for My Sourdough Starter?

Feeding your sourdough starter twice daily (once it begins to develop) helps the yeast population grow faster and helps strengthens your starter. It also creates a balanced, less acidic environment.

An overly acidic sourdough starter is thin, runny, smells of nail polish remover or strong vinegar, and will lead to flat, dense, gummy sourdough loaves. So by increasing the frequency of feeding, we avoid an acidic sourdough starter!

When Do I Start Feeding My Sourdough Starter Twice a Day?

You don’t necessarily have to start doing twice daily feeds on day 10. This is just what was appropriate for my starter. You might need to start doing twice daily feedings a few days earlier, or a few days later, and that’s totally okay!

So when do you actually know when it’s time to do twice daily feedings? When it doubles in size between daily feedings for a few days in a row, or when you notice a strong nail polish remover smell, that’s your sign to switch to twice daily feedings.

These are signs your yeast is hungry, and is munching through all the food you’re giving it. So look at your starter, not the calendar! If this happens on day 7, or 12 for you (or earlier, or later), don’t worry. Many things affect this, like temperature, flour type, and the environment.

Day 11

Day 11: Feed twice daily! Discard 100g starter, keep 50g in jar. Then feed with 50g flour and 50g water. Wait 12 hours (not 24) and repeat. Total sourdough starter weight in jar: 150g.

Much the same as the day before! Your starter should be very bubbly, with a mousse-like texture. By the second feed, (so 12 hours after the first feed), your starter should have doubled in size. And if it had a nail polish remover smell in the past few days, that should start to disappear as you balance out the acidity. Instead, your starter should start to smell yeasty and pleasant!

Day 12

Day 12: Feed twice daily! Discard 100g starter, keep 50g in jar. Then feed with 50g flour and 50g water. Wait 12 hours (not 24) and repeat. Total sourdough starter weight in jar: 150g.

Pretty much the same as the day before! Your starter should be bubbly, with a mousse-like texture, and doubled in size by the time you do your second feed on day 12.

Any nail polish remover smell should be almost gone, and instead your sourdough starter should smell yeasty and pleasant.

Day 13

Day 13: Feed twice daily! Discard 100g starter, keep 50g in jar. Then feed with 50g flour and 50g water. Wait 12 hours (not 24) and repeat. Total sourdough starter weight in jar: 150g.

This is when it is very tempting to bake with your sourdough starter. You’ve had a few days of consistent doubling in size, it’s beginning to smell lovely and yeasty, and it’s full of gorgeous bubbles. For safe measure, I like to do the twice daily feedings an extra day or two, just to be safe.

By this point, your sourdough starter should be doubling reliably in between your twice-daily feedings (perhaps more than doubling!). It should be very bubbly, with a mousse-like texture. It should also smell yeasty, or like a pleasant fruity yoghurt.

Day 14

Day 14: If your sourdough starter has been reliably doubling in size 4-8 hours after feeding for a few consecutive days, it’s ready to bake with!

On day 14, you may well be ready to start baking your first sourdough loaf! If your sourdough starter has been reliably doubling in size 4-8 hours after feeding for a few consecutive days, then you can bake your first loaf of sourdough!

How Do I Know If My Sourdough Starter Is Ready to Bake With?

If your sourdough starter is not reliably doubling 4-8 hours after feeding for a few consecutive days, (it barely doubles, or it takes much longer to double), it’s simply not strong enough yet. And this is totally okay. Continue feeding and discarding twice daily (or ‘peak-to-peak’) until it develops and matures. Sourdough starters are alive, and so many things affect them (temperature, flour type, environment).

Sometimes it’s simply too cold in your kitchen, and your starter rises very slowly! Sourdough starter (and sourdough bread) rises faster in warm environments, slower in cooler environments. If it’s very cold in my kitchen, I sometimes let my starter sit on outside balcony where it’s warmer, and I see faster growth.

And if I’m being honest, if you have a sourdough starter that’s ready to bake with on day 14, you’re probably one of the rare ones! It can take 3 or 4, sometimes even 6 weeks to build a strong starter. So don’t be disheartened if yours is ready to bake with a little later. Again, look at the starter, not the calendar!

If your starter isn’t quite ready, read below for tips on how to strengthen it. But at this point you’re probably wondering what to do with all the sourdough discard you’ve been collecting. Here are a few ideas!

What to do with Sourdough Starter Discard

You do not need to actually discard any sourdough starter. Especially when first making a sourdough starter from scratch, there’s going to be so much discard that it’s such a shame to throw it all out! But there is absolutely nothing wrong with it, and you can bake so many different things with sourdough discard. My absolute favourite thing to use it for is in sourdough pancakes (recipe coming soon!).

Plus, using sourdough discard in baking has so many benefits!

Benefits of Using Sourdough Discard in Baking

• Baking with sourdough discard avoids food waste!
• Sourdough discard enhances flavour. Using sourdough discard in baking enhances flavour by giving a complex, slightly tangy taste since the flour is fermented. This flavour is more pronounced if you do a long ferment (12-24 hours) in whatever sourdough recipe you are using.
• Using sourdough discard leads to softer, fluffier baked goods! Baking with sourdough discard give you a more tender, delicate, and softer crumb in cakes, pancakes, waffles, or any baked good. This is mainly because the flour is already fermented in sourdough discard, and the anti-nutrients have started to break down. So using sourdough discard in baked goods actually helps break down the gluten structure, leading to softer, fluffier cakes!

• Baking with sourdough discard improves digestibility. Because of the reduction in anti-nutrients in sourdough discard, minerals are more bioavailable, making your baked goods more nutritious and easier to digest! If you do a long ferment (12-24 hours) in your sourdough discard recipe, you further break down the anti-nutrients, and get maximum health benefits from using your sourdough discard. This is especially useful if you are following a low FODMAP way of eating since the long ferment helps make your baked goods low FODMAP!

How to Maintain Your Sourdough Starter

Keep an eye out for my upcoming, in-depth post on how to maintain a sourdough starter. But if you’ve baked your first loaf of homemade sourdough bread, you’ll be wondering what to do with your starter now!

One of the most common misconceptions is that sourdough bread or sourdough starter is high-maintenance. It’s simply not true. I have heard from so many people that it takes too much effort to feed their starter everyday, and that they don’t want to bake bread every day, or every other day.

I’m here to tell you, you don’t need to feed your starter everyday! As much as I love freshly baked homemade sourdough bread, I don’t bake or eat it very often. So my starter is in the fridge, until I need it. And I use what is called the ‘scrapings’ method. Here’s how it works!

Scrapings Method for Sourdough Starter

Leave all but a few scrapings of sourdough starter left in your jar. A tablespoon or less is fine, but there’s no need to measure.

Then store that (basically) empty jar in your fridge. When you plan on baking sourdough bread, pull it out of the fridge the night before, feed it with flour and water, and the next morning you’ll have a bubbly, active starter that’s ready to bake with! Once you use that starter in your sourdough recipe, place the almost empty jar of scrapings back in the fridge until you want to bake again. That’s it!

Tip: With the scrapings method, you only feed your sourdough starter scrapings with as much flour and water as the sourdough recipe needs. So, for my homemade sourdough bread recipe, you need 100g sourdough starter. This means you would feed your sourdough scrapings with 50g flour, 50g water for a total of 100g. Then you use that 100g in the sourdough bread, and the scrapings go back in the fridge. No waste, no fuss, no maintenance!

How Long Can Sourdough Starter Stay in the Fridge?

Short answer? A long, long, time. Longer than what you’ll read online.

Some people tell you to feed it once a week, or every other week. I have never once randomly fed my starter if I’m not baking bread! The only time this would make sense for me, personally, is if I want to create some sourdough discard to use in a baking recipe. But there’s no need to feed it for the sake of it. Sourdough starters are so resilient! I’ve sometimes kept mine in the fridge for 3 or 4 months (sometimes longer) and when I take it out to bake with, it wakes up with a good feed.

You may see a dark liquid in your jar if it’s been a while since you’ve fed it. This is just hooch, and I always stir it back into my sourdough starter once I feed it. No biggie! You can also pour it out if you like. The only time you should worry is if you see mold, or orange or pink streaks. If that’s the case, do not risk it. Sadly your sourdough starter’s life is over (but good thing you know how to create a sourdough starter from scratch!)

How to Strengthen a Weak, Runny, or Acidic Sourdough Starter

A healthy sourdough starter should be thick, fluffy, full of bubbles, with a mousse-like, airy consistency.

But let’s say your sourdough starter from scratch is runny, or smells like nail polish remover. Or maybe it’s not rising very much, or it’s rising very slowly. The most common cause of all this is a sourdough starter that is overly acidic. That means the lactic acid bacteria is thriving and is outperforming the yeast.

And when this happens, the yeast can be sluggish, leading to weak starters that are runny, and don’t rise very well. If you use a very acidic sourdough starter, your sourdough bread will turn out dense, gummy, and flat. Luckily it’s quite easy to fix a weak, acidic, runny sourdough starter!

If this happens, I like to do a thicker feed, with a 1:5:5 ratio. This just means 1 part starter is fed with 5 parts flour and 5 parts water. To do this, discard all but 10g of your sourdough starter (scrapings!). Then feed with 50g flour and 50g water.

The thicker feeding ratio reduces the concentration of acid, provides more food, and helps to boost yeast activity. Make sure to leave it in a warm spot, and once it doubles in size, discard and repeat the same process daily, sticking with the 1:5:5 ratio until your starter balances out (this is called ‘peak-to-peak’ feeding). It should be thicker, smell less like nail polish remover and more like yeast or fruity yoghurt, and have a mousse-like consistency.

Final Tips on Making Sourdough Starter From Scratch

You’ll notice I haven’t mentioned the float test yet. This is when you drop some starter into a glass of water, and if it floats (because of the carbon dioxide gas produced through fermentation), it’s ready to use.

Although it’s a helpful test when you’re first starting out, I think the best sign of whether your starter is active enough is by seeing whether it’s doubled or tripled in size. This visual cue is a clear sign of activity, and honestly, I rarely use the float test anymore.

Finally, making sourdough starter from scratch is a huge achievement! It teaches you one of the most important things about baking sourdough: patience. Sourdough bread is not something to be rushed. It’s a beautiful form of baking that forces you to slow down, enjoy the process, and learn to use your intuition when it comes to bread dough.

So don’t be overwhelmed or discouraged by all the information you read on making a sourdough starter from scratch. At the end of the day, it’s just flour, water, and a bit of time. We’ve been baking sourdough for thousands of years, so stick with it, and, like me, you’ll look back and wonder why you ever thought making sourdough starter from scratch was complicated!

I truly hope this guide for sourdough starter from scratch was helpful to you! If it was, I would be so grateful if you left a 5-star review and a comment to let me know how it went! xxx