One of the great things about baking real bread at home is that it requires so few ingredients – flour, water, salt and leaven. That’s it!
The addition of baker’s yeast is the most common way to leaven a loaf of bread, with the loaf being made to rise through the power of fermentation.
Soda bread, on the other hand, uses baking soda to create volume, reacting with an acid to form carbon dioxide and breathe life into the loaf.
Yet baker’s yeast and chemical leavening agents such as baking powder or baking soda are not the only ways to bake bread, and in fact are relatively recent developments in the world of baking.
For thousands of years before this, bakers harnessed the power of naturally occurring micro-organisms – wild yeasts and bacteria – to ferment their loaves. They used, in other words, a sourdough.
The Wild Ones
There are many reasons why you might want to bake bread without yeast or chemical leavening agents. Perhaps you or someone you are baking for is allergic to baker’s yeast (speaking of food allergies, did you know you can make macarons without using almond flour?), or you might want to skip unnecessary chemical additives.
There are however many other advantages to baking sourdough bread, as you will soon find out.
A sourdough is created by simply mixing together flour and water, and allowing the wild strains of yeast and lactic acid bacteria present on the flour to form a stable culture within the mixture.
By feeding the sourdough regularly these micro-organisms are kept active and can reproduce indefinitely, providing a little powerhouse of activity to kick-start your baking.
The wild yeast will give the bread volume, much like baker’s yeast, while the bacteria help to build additional flavor in the loaf. They produce lactic acid, which lowers the pH of the sourdough and protects it from attack from other, undesirable micro-organisms.
This is what gives it the name sour-dough. But do not fear, a sourdough loaf does not have to end up tasting sour – it just gives it an extra dimension of flavor!
Working with Sourdough

Once you have an active sourdough starter up-and-running, baking with it requires only a few adjustments to your usual baking practices and a little planning ahead.
You can make your own sourdough from scratch, as detailed below, purchase a dehydrated sourdough online, or try to acquire one from a bakery.
Most small bakeries baking sourdough bread will be happy to give you a little bit of their starter which you can then keep fed at home – just remember to bring along a small container to make it easier for them!
Caring for your sourdough is simple, but bear in mind that you want it to be active when you plan to use it for baking (here’s how to tell if your starter is bad). If you are baking bread more than once a week, you can leave your sourdough at room temperature and feed it daily.
If you bake less often, then keep it in the refrigerator and feed it once a week, taking it out and giving it a couple of extra daily feeds before you will bake to “freshen it up.”
To feed it, discard most of the starter, leaving about 10-30%, and add an equal amount of flour and water by weight, or a little extra water if using wholemeal flour.
These ratios are guidelines, and a sourdough can be controlled by adjusting them – a wetter sourdough will ferment more quickly, while a stiffer one will give you more time to catch it at its peak. Experiment, and you’ll soon find a rhythm that suits you.
If you are used to baking bread with baker’s yeast, you will probably find that a sourdough takes a little longer to rise. This can be used to your advantage however, as you can steer the various stages of the bake according to your lifestyle.
A sourdough can be refreshed in the evening for example, mixed into a dough and shaped the next morning, left to prove during the day and then baked in the oven when you come home in the late afternoon.
Alternatively, you could take advantage of a “cold proof” by retarding the shaped dough in the refrigerator overnight and baking it first thing in the morning. Great if you want freshly baked bread for breakfast!
Finally, sourdough will not be as vigorous as dough made with baker’s yeast, so you will need to be a bit more careful while handling the dough.
It may not tolerate being knocked back as vigorously as a conventional dough, so a gentle folding of the dough is a great alternative. This can produce loaves with a fantastic open crumb in the French or Italian style.
Added Benefits
The slower fermentation of sourdough bread brings many additional benefits.
The added time gives both enzymes present in the flour and the micro-organisms in the sourdough more opportunity to build up flavor in the dough and release valuable nutrients locked up in the flour.
The lactic acid improves the keeping qualities of the bread, while the long fermentation makes the bread more easily digestible.
Many people who have struggled with store-bought bread are turning to home-made sourdough after discovering how much better they tolerate it, and how great it tastes.
How to Make a Sourdough Starter

Making your own sourdough starter from scratch is extremely rewarding. It is amazing to think that you have raised and nurtured your own colony of wild yeast and bacteria from just flour and water, and that all the tasty loaves you will bake from it derive from this initial starter.
Creating a starter is no exact science, so the quantities suggested are approximations. It does require a little time and patience, but so long as you keep your sourdough fed regularly this is a process you will have to do only once. Your starter could be with you for life!
General Notes
Many “recipes” for creating a sourdough starter call for all manner of exotic ingredients such as raisins, grated apple, dried apricot, etc.
The idea here is that these fruits provide their own populations of micro-organisms, helping to kick-start the starter and provide unique flavor combinations.
While there is nothing wrong with this, so long as you use fresh, preferably organic flour to create your starter, there should be plenty of wild yeast and bacteria present to get it started. Any flavors provided by the fruits are also likely to be diluted after a couple of feedings anyway.
Wholemeal flour, and especially wholemeal rye, will give a very fast and vigorous fermentation, due to there being higher quantities of micro-organisms on the flour bran. You can use whichever flour you like however for your starter, but bear in mind that timings may vary.
Learn more about the purpose of ingredients in baking.
Day 1
Mix 150g flour and 250g water at about 35°C (95°F) in a container with a lid. Plastic or earthenware are ideal, but if you use glass be sure not to close the lid tight, as the pressure will build up when the starter begins to ferment.
Avoid metal containers as the acid produced could react with these. The container should be about four times the volume of your initial mixture, to allow for later feedings and expansion.
Whisk the mixture thoroughly to get plenty of oxygen into the batter, loosely close the lid and let it stand in a warm place (around 30-35°C or 86-95°F is ideal).
Days 2-3
Check the starter once or twice a day, and whisk it a little to get in more oxygen. Repeat this mixing until small bubbles start to appear on the surface of the starter, the first signs of fermentation. You will also notice that the aroma will start to change.
Day 4 (or as soon as fermentation has begun)
Once the starter has started to ferment you can give it its first feeding. Mix in the same amount of flour and warm water as on Day 1, and let it stand for another 24 hours.
Day 5
Discard half of the mixture and add in the same amount of flour and water, but cold this time.
Day 6
At this point your starter should be fermenting vigorously, with large bubbles forming and the mixture swelling up in size. The aroma should also have matured somewhat, becoming less harsh and more pleasant.
At this stage your starter is ready to use, but a week of additional daily feedings (removing half and replacing with new flour and water) will make sure that it is very active before its first use.
Basic Sourdough Bread Recipe

Like all bread baking, so much is dependent upon your particular circumstances, ingredients and equipment, with infinite room for experimentation.
Nonetheless, an example recipe can help to point the way on your journey into sourdough bread baking. The following gives an idea of the rhythm of baking with sourdough – feel free to adapt it to your preferred style of baking.
While this recipe doesn’t require a bread maker, you might be interested to learn when to use one.
Ingredients (makes 2 loaves)
- 200g sourdough starter
- 300g wholemeal flour
- 700g strong white bread flour
- 650g water
- 20g salt
Day 1
Refresh your sourdough starter in the evening. 120g flour and 120g water will give you enough for the next day’s bake while leaving some over for the next refresh.
Day 2
Mix all of the ingredients together into a dough, and knead until it starts to feel elastic. You can add more flour if the dough is too sticky, but a wetter dough with give a softer and airier crumb. Cover with a plastic bag or a damp cloth and allow to rest for about an hour.
Fold the dough every 30 minutes, gently lifting the edge up from the bowl and folding it over towards the top, rotating the bowl in quarter turns and repeating so that you have folded it four times.
Alternatively, you could place the dough on your work surface, and gently stretch and fold in the same way, before returning the dough to the bowl.
Continue to fold the dough until it has become light and airy – this could take several hours depending upon the temperature in your kitchen and the activity of your starter. Once it is ready, divide the dough into two and form each into a round.
Place in a floured banneton (or an alternative), cover with plastic and allow to prove until the dough has increased about 50% in size. You can either allow the loaves to prove until they feel airy and delicate before baking, or put them in the refrigerator and cold prove them overnight, baking the next morning.
Set your oven to 220°C (428°F) and put in a baking stone or baking tray. Once the oven is hot, remove the loaves from the banneton and transfer them to the stone with a peel, or remove the tray and place the loaves on it directly.
The loaves can be slashed with a knife or ‘lame’ to help them rise in the oven. Reduce the temperature to 200°C (392°F) after 15 minutes, and bake the loaves for about 30-40 minutes in total, or until they are baked to your taste.
Allow the loaves to cool completely before slicing and enjoy!
Sarah is the founder of Baking Kneads, LLC, a blog sharing guides, tips, and recipes for those learning how to bake. Growing up as the daughter of a baker, she spent much of her childhood learning the basics in a local bakery.