Delicious Sourdough Facts

If you enjoy this post and want to learn more about sourdough you can subscribe to my newsletter and get my ‘Getting Started With Sourdough’ ebook for free.

After sharing how I get my sourdough starter ripe and bubbly ready for baking and then how I bake my sourdough loaves last week, so I thought it was only fitting so share some fabulous facts and information about sourdough.

This is a long one, so bookmark it for later or settle in with a cuppa, you’re in for a wild factual ride.

sourdough loaves

The Starter

  • Simply put sourdough starter is made from flour and water
  • Wild yeast is the key to sourdough starter – wild yeast lives everywhere, in the bag of flour, in the air, etc. Commercial yeast has replaced wild yeast in baking because it’s easier to control, it’s easier for bakers to store and it’s easier to mass produce.
  • Wild yeast (saccharomyces exiguus) is a different strain of yeast than commercial, packaged yeast.
  • Wild yeast can be fuss and finicky, and needs a vessel, the sourdough starter, to be useful to bakers. This vessel needs to be constantly monitored and maintained.
  • Since wild yeasts are already present in all flours, the simplest way to create your very own sourdough starter is to combine flour and water and wait patiently.
  • Wild yeasts also like cooler temperatures, acidic environments and works much more slowly to proof breads.
  • How ever you can buy a dried starter to give you a head start.
  • Yeasts adapt to what ever environment it is in. So if you were to buy some starter, it would quickly adapt to you location, picking up wild yeasts in your area and develop your very own local sourdough.
  • To get your starter ready for baking, follow this tutorial
  • Once you have your sourdough starter up and running and it gets nestled safely into the fridge and then forgotten about. When you next get your starter out to bake you may see a dark liquid, it’s called ‘hooch’. You can either simple pour if off, or stir it in.
  • Hooch is evidence that your starter has exhausted itself and needs to be refreshed. It needs a 1:1 feed of flour and water.
  • You must feed the starter periodically to prevent the organisms from exhausting the sugar supply in the starter, this is called ‘refreshing’.
  • Along with the wild yeasts there is also a friendly and non-harmful bacteria called lactobacillus.
  • Lactobacillus feed on sugar and produce two kinds of acid as a by-product: lactic acid that gives the sourdough its mellow rich flavor and acetic acid that gives its tang and punch.
  • Depending on the conditions of your starter, one or the other of these acids is produced in greater abundance. Liquidy starter (near equal balance of flour and water) makes more acetic acid and your bread will have a more distinct sour flavor. A stiff starter (higher percentage of flour to water, about 2:1) makes more lactic acid, giving your final bread a more mellow, rather sweet taste.
  • Wild yeasts are crucial in this environment because commercial yeast would never survive in such an acidic environment.


  • Levain is French term for a mixture of flour and water that has been colonised by yeasts and bacteria and leaven is English and acts as both a verb and a noun
    • verb Bread can be leavened
    • noun Sourdough starter can also be known as leaven
  • Levain is an offshoot of your original starter, when you take some from your original starter and feed it up to get ready to bake.


The big question when it comes to bread making seems to be do you use bread/bakers flour or plain/all purpose flour for sourdough bread?

  • Plain flour/All purpose flour is a blend of hard and soft wheats and is wonderful for making airier breads, like baguettes.
  • Bread flour/Bakers flour has more protein than all-purpose flour, so it’s sturdier and a good candidate for rustic loaves with a good chew.

I’ve always used bakers flour, I like the sourdough chew.


The purpose of baker’s percentage is to put the weight of all ingredients in relation to the flour used in the recipe. The reason to do this, is that with just a few simple calculations you can have a greater understanding of how much of which ingredients you’d like to use, but also to predict the outcome of the bread.

The Total Flour Weight (TFW) is always expressed as 100%, from this the other values are calculated.

Using the recipe from this post and the sourdough feed up in this post:

  • 300 gm sourdough starter at 66% hydration (1 cup : 1 cup) = 187 gm water + 112.5 gm flour
  • 600 gm water
  • 1000 gm flour
  • 18 gm salt

From this, the rest of the ingredients can be converted by dividing the individual ingredient weights (I) by the total flour weight (TFW), and multiplying by 100.

Calculation: (I/TFW)x100 = %

So, for the water: (I/TFW)x100 = ((600+187) / 1112.5)x100 = 70.7%.

This not only gives the percentage of water, but also the hydration of the final dough.

You can also work out the percentage of salt in the dough: (I/TFW)x100 = (18 / 1112.5)x100 = 1.6%.

I think that for the home baker it isn’t crucial to understand how to both figure out the hydration, or bake to certain hydrations. It’s interesting but not important. To the commercial baker it has a little more value, loaves need to be consistent, and even the slightest hiccup can effect the production and profit.

I recommend when you feel comfortable with your regular baking, give it a go, it’s fun to be able to say ‘this is a 70.7% hydration loaf’, if not a little wanky.

The Dough

  • You can find my standard loaf recipe here.
  • For best results use an electric scale and bread flour for better gluten development and overall texture.


  • Awe-tow-lees is the fancy term for “mix only your flour and water together, and let it sit for twenty minutes before adding salt and kneading”
  • This stage was first introduced by Professor Raymond Calvel, who noticed that when the dough was given a chance to hydrate without the addition of salt, it produced a superior outcome in the end.
  • Autolyse refers to the destruction of a cell by its own enzymes, of ‘self-spliting’. In baking, this means that enzymes in flour (amylase and protease, if you really want to know) begin to break down the starch and protein in the flour.  The starch gets converted to sugar, and the protein gets reformed as gluten.
  • Why would you want to do this?  When you knead the dough, aren’t you just trying to do the same thing – form gluten?  Well, yes, ultimately; but when you knead dough, you also oxidize it (expose it to oxygen).  Over-oxidized (or, over-kneaded) dough results in colour and flavor loss in a finished bread, which means it’s pale and tasteless.  By giving the mixed flour and water time to go through autolysis on their own, you achieve the same result, but without any of the unpleasant effects of oxidation.
  • By giving the four and water time to autolyse you are providing the dough the opportunity to form gluten without the unpleasant results.
  • Personally, I don’t do this. Just what works for me.

Bulk Fermentation

  • Bulk fermentation is the initial long resting period when you wait for the dough to 1 1/2 to double in size.
  • Cover your bowl with glad wrap, a wet tea towel or shower cap and set aside until risen.
  • This rest is very important to the development and strength of the dough.
  • Your dough is ready when it no longer looks dense, has increased in size to roughly 1 and a half to double, and when pulled away from the bowl there is lots of action and evidence of bubbles with the ‘stringy cheese’ effect. This ‘stringy cheese’ effect is the important part.
  • This rise can take any where from 4 hours to 24 hours due to the nature of the wild yeasts. It’s very important to watch your dough not the clock.


  • Slashing is a crucial aspect of the final stages of sourdough baking.
  • Originally used as a way to distinguish bread loaves in a communal oven.
  • The three main reasons for slashing your loaves are:
    • control how the dough expands during “oven spring”
      • Oven spring is the final burst of rising after the bread goes into the hot oven before the crust hardens.
    • prevent the dough from bursting where the seams are weak during baking
    • enhance the final appearance of the bread
  • Use a sharp blade
  • When scoring a wet and sticky dough, wet or oil your scoring utensil and slash a more shallow cut, and you can wet or oil your blade between cuts.
  • Gently hold onto the end of your dough for stability during scoring.
  • Dry out the skin of your dough with a fan or breeze before scoring.
  • Do not press down onto your dough with your scoring utensil, let the blade do the work.

The Bake

  • I bake in an a 30 cm enamel roster with lid.
  • Baking in a pot traps moisture and provides the dough the opportunity to have a good oven spring before the crust starts to harden too much.
  • These elements play a key role into controlling how the slashes open up or ‘bloom’.
  • If you don’t have a pot appropriate to bake in you can bake on a tray. Treat the dough the same, shape, slash then spray well with water. Bake for 20 mins at 220℃, then reduce heat to 175℃ for a further 30 mins.
  • Make sure you allow your bread to cool. DO NOT give in to the temptation to cut into a hot loaf! The insides have not finished cooking yet, and the bread is not fully digestible when it is still hot from the oven. It also stales much quicker.

This has been a long one, thank you for sticking with it but I really loved learning more about sourdough and being able to share these facts with you.

I think this post will be a great one to bookmark as a reference for future baking experiences.

Have you started baking sourdough yet?

If not:

  • Buy your starter and ebook pack here
  • Check out how I get my starter ready to bake here
  • Have a look at how I bake my bread here

If you enjoyed this post and want to learn more about sourdough you can subscribe to my newsletter and get my ‘Getting Started With Sourdough’ ebook for free.


To thank you for all of your support throughout my sourdough journey I’ve got two packs to give away that’ll help you begin your very own soughdough journey.

Each pack contains an enamel pot, 2 dough scrapers, a copy of my ebook and your very own sourdough starter, every thing you need (except the flour) to bake your first loaf.

There are two opportunities to win:

  1. Sign up to my newsletter HERE (if you already have, then you’re already in the running)
  2. Find this photo on Instagram, follow me if you haven’t already, like the picture and tag 3 friends in the comments – you can enter on Instagram as many times as you’d like.


 Terms and conditions:

The winning entries will be chosen at random. Multiple entries on Instagram are welcome as long as different users are tagged each time. The giveaway will commence Friday May 6th and the winner will be announced Tuesday May 17th.

4 thoughts on “Delicious Sourdough Facts

  1. Thanks so much, Clare. Every bit of information is a help in achieving that perfect loaf. I have printed this out (together with the recipes from the links) and will attempt a loaf this coming weekend (I haven’t had time over the past few weeks!). I have a large ham hock which I am going to make pea and ham soup with so will need some bread for sopping- oh yum!

    Cheers – Joolz xx

  2. Thanks for the awesome post, the whole hydration thing confuses the hell out of me! So many recipes call for a 100% hydration starter…..I am sitting here thinking, like, what the hell does that mean? I have my starter, can i just bake now?? 🙂 I will start slow and experiment, will print and keep this page on my favourites for future clarification. Thanks for taking the time to put all of that down Clare. Another question i have is, how much starter do we keep aside in the fridge? For all purposes i would bake two loaves a week. If i need 300gm of starter should i keep that amount aside? or extra and then feed it to refresh it? So confused.

    1. I still don’t get the hydration stuff, but the bread works and it’s yummy! I just keep my container about half full in the fridge, no measurement, sorry. Just keep any you don’t use until your container gets too full. I try to keep it as easy as possible.

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