how to make a sourdough starter from scratch?

THE SOURDOUGH STARTER is the most important element when it comes to sourdough baking. Your sourdough starter is the one responsible for making your dough rise, but also playing a role in the final texture and flavour of your bakes.

For a more detailed step by step guide, including variations that might occur (as each starter will develop differently), I have written a complete guide on how to make your own starter and the maintenance after.

First of all, what is a sourdough starter?

A culture of ‘wild/natural’ yeast & bacteria, replacing the commercial yeast that helps your dough rise.

The sourdough starter is made of two very basic ingredients, water and flour. During fermentation the mixture becomes colonised by wild yeast and lactic acid bacteria. Some of these are coming from the flour, some from your environment and also your hands.

Yeast is that responsible for the bubbles, the released gas. This fills the gluten network and makes not only your starter to increase in volume, but also your bread rise. The yeast is also responsible for producing alcohol. It’s the dark watery layer you get on the surface when the starter is left for too long unfed.

Bacteria are those responsible for creating lactic acid during the fermentation. This will influence the acidity profile of your starter, and the sourness of your bread. This is what ultimately gives the unique aroma and texture of the sourdough.

The characteristics of your starter will be defined by couple of things. The flour you use, the temperature in your kitchen, how often your starter is refreshed. But also things like your environment, your hands & microbiome. That’s why no two starters are the same, even if most of the variables are similar.

What if I don’t have a starter?

You can go the easy way and ask a bakery to give you some. Or ask another baker living close-by to share some, or a friend who’s into baking. Or ask me to send you some dehydrated sourdough starter (subject to your location and postage costs). Getting a starter ready to use takes off the pressure of making it work and the frustration of failures. This way you can get straight into sourdough baking.

Or you can make your own sourdough starter from scratch. You just need 2 simple ingredients, flour and water and a lot of patience.

HOW TO MAKE A SOURDOUGH STARTER FROM SCRATCH?

Although at first it sounds like an easy task, it may not be as straightforward as other processes. You rely a lot on the flour you use, temperature in your kitchen and the wild yeasts and bacteria present in your home. You should not get frustrated if it doesn’t go well from the first attempt.

I have experimented with making a starter from scratch several times over the last years. Some were successful on day 3, some on day 10, some were abandoned. You may find it complicated at times, but when you nail it, you will be over the moon.

Happy to share with the steps to follow to make your own sourdough starter from scratch. As everything to do with sourdough, there will be variations and development may vary. That’s why the sourdough starter complete guide might be a more suitable to follow.

Temperature: you need a warm kitchen for the starter to take off, ideal temperature around 24°C / 75°F. In a cold environment (21°C / 70°F or below) it might take longer to take off, looking rather sluggish or not taking off at all. If much colder, it might not take off at all.

Water: bottled water, filtered tap water, any water is ok to use as long as you would normally consume it. In winter time best to use warm water, it can have up to 36°C / 96.8°F. In summer, when it’s hot, use cold water instead.

Flour: best to use a flour that’s rich in protein and has the ability to develop gluten.

Any bread flour / strong white flour with a protein level around 12-13% should work well. You can also use rye flour, and lastly you can also try a mix of white wheat and rye.

step by step instructions

Day 1.
Mix 30g water + 30g flour, stir well in a jar, place the lid loose and leave on the counter. It needs to be in a warm spot, move it in the warmest spot in your house. Do NOT overheat it though. Idea! you could place it in the oven with the light on, however don't place it very close to a heat source. You don't want to cook it.

Day 2. max 24h later
What to expect: 
a few bubbles, slight rise or even no rise in volume, texture changing to a rather gluey one when stirred in. These are all normal, so give it another feed when 24h have passed.

Do NOT discard, but ADD 30g water +30g flour, stir well, place the lid loose and leave on the counter.

Day 3. Max 24h later

What to expect:
more bubbles, DOUBLES IN VOLUME, very gluey when stirred in, smelling milky, but also sour. These are all your signs that your starter is doing well, you can now discard. Keep 40g starter and add 40g water and 40g flour. Stir well, loose lid, on the counter.

however, if there is not much activity vs previous day, do NOT discard, but ADD 60g water and 60g flour to help build the culture.

Day 4. Max 24h later

What to expect:
very bubbly, doubles in volume, very gluey when stirred in, smelling milky, but also sour. These are all your signs that your starter is doing well, you can now discard. Keep 40g starter and add 40g water and 40g flour. Stir well, loose lid, on the counter.

however, if there is not much activity vs previous day, do NOT discard, but ADD 40g water and 40g flour to help build the culture.

If you have not discarded until now and your starter still doesn't show any increase in volume, discard nevertheless, as you start building an enormous amount of starter. And it's not only the size of it, but also the fact that with size, it tends to become more acid/sour and the chances for it to take it off decrease. Keep 40g starter and feed with 40g water and 40g flour.

Day 5. Max 24h later

What to expect:
very bubbly, doubles in volume, very gluey when stirred in, smelling milky, but also sour. These are all your signs that your starter is doing well, you can now discard. Keep 40g starter and add 40g water and 40g flour. Stir well, loose lid, on the counter.

If there is still not much activity, my advice is to try and change the flour or if you think your kitchen is too cold, move your starter to the warmest spot in the house. Keep 40g starter and add 40g water and 40g flour. However if you have discarded the day before, do not discard again, just add 40g water and 40g flour.
Stir well, loose lid, on the counter.

Repeat the above until your starter shows clear signs of activity - ideally it would double in volume for at least 3-4 consecutive feedings before you start using it. Somewhere between days 5 - 10 you can have an active starter and ready to use

To help visualise it, check this video.

INFO to be used WITH the instructions above

🌾 The ‘DAYS’ in the schedule are to be used as guidance. Based on how your starter develops you might have to bring feedings forward (feed at 12 h instead of 24 h), very unlikely to have to delay it

🌾 If the starter stops growing in volume, and instead you see it collapsing, move to the next feed even if the 24h have not passed. It can also happen that it doubles in volume in 6-8h (happy days), just go ahead and feed it.

🌾 If within 24 h from feeding your starter shows a watery layer at the top (or even in the middle or bottom of the jar). OR you notice yellow patches and a cheesy smell, move to the next feed even if the 24h have not passed.

🌾 Say you’re trying to make a white wheat starter (bread flour in the US or strong white flour in the UK) and there’s not much activity after day 4, try to mix with rye flour the next feeding (go for 50% white flour – 50% rye)

🌾 There will have to be discard, because otherwise you will be building an enormous amount of starter, as you’ll be adding water and flour at every feeding. Not only this, but the culture will be more acid, very liquid and will not rise much in volume as the yeast won’t have enough food to feed on and release the gas.

🌾 In the first days of discard, the mixture won’t have enough strength to raise a dough. If not too sour (you could tell this either by its smell) or if no strong unpleasant odour, you could use the discard for something like pancakes, crackers, etc – any recipe which is not calling for yeast.

🌾 When your starter is ready, you can make your first bread (yaaaay), and then it goes into maintenance mode. You can now move it to the fridge, and fed before using it next time. For more guidance, check the Starter Maintenance section

most frequently asked questions

How do I know the starter is ready?

I advise you to wait for your starter to double in volume for at least 3-4 consecutive feedings. Only then you can make your first bread. You want to make sure it has enough strength to rise your dough and a healthy culture of wild yeasts & bacteria

Do not attempt to make your first bread if starter has doubled for the first time in volume, day 3 for example. While it's bubbly, it won't have the strength to leaven your dough and make it rise.

It might float or not, the float test should not be the only way to judge its readiness. You should also consider the other signs to assess your starter readiness: bubbles, increase in volume, sour smell and flavour, loose consistency

It's ready, I make my first bread, what next?

It can go in maintenance mode. Before moving it into the fridge, I would give it another couple of feeds to strengthen it.

Should the lid be loose?

Yes. During fermentation, yeast will produce gas which has to escape somehow. If you close the lid tightly, you might experience a burst when opening it.

My kitchen is very cold - below 20°C/68°F

Yeasts love warm environments to be active. Making a starter from scratch at low temperatures can be challenging, I am not saying impossible. Try and find a warmer spot in your house to store it after feeding. Definitely use warm water (36°C / 96.8°F) when feeding.

How to track changes in the volume of the starter?

You might want to use a rubber band  or an erasable pen (unless your jar is graded)

My starter has developed a strong unpleasant smell. Is this normal?

Yes, the starter may develop a strong unpleasant odour in days 3-4. There’s nothing to worry about, the odour tends to disappear after a couple of feedings.

My starter is particularly liquid. Is this ok?

If your starter seems particularly liquid at some point, increase slightly the quantity of flour (say 45g instead of 40g) at the next feeding.

I am following your instructions to make a starter from scratch, but nothing happens. What's wrong?

It could be a couple of things.

No 1 is the temperature. Ideal temperature is between 23° - 27°C / 74 - 80°F. In a cold environment (21°C / 70°F or below) it might take longer to take off, looking rather sluggish or not taking off at all. Try to find a warmer place in your house, use warm water at feeding (36°C / 96°F)

The other most common cause is the flour. Flours are all so different, and when building a starter we are relying on the wild yeasts and bacteria that comes with it. It comes all the way from the grains, and further from the soil where the grains have been grown

What flour should you be using? Ideally a flour that’s rich in protein - it can be anything like bread flour, strong white flour (and its equivalent in other countries). If you can use stoneground white, wholemeal flour or rye flour, even better. Those tend to be richer in enzymes and the good stuff for the culture of wild yeast & bacteria to take off

If you have tried with bread flour and it’s not taking off, try to mix it half/half with wholemeal or rye.

The process is NOT the same for all, as development can differ from starter to starter. It's never linear, and it comes with ups and downs.