Sourdough Basic Principles and Terminology

Sourdough Basic Principles and Terminology

Sourdough seems complicated but it is unbelievably forgiving.  It would have to be because even I can manage it.  People have been making it for thousands of years. There are hundreds of ways to make sourdough with different techniques and varying percentages but it really helps to know some basic terms. When there are literally only 4 ingredients: flour, water, starter, and salt – we would be totally confused if we didn’t have different names for different parts of the process.

A quick note on what makes sourdough ‘sourdough’:  it should be flour + water + starter + salt.  That’s it.  No conditioners, artificial leaveners, preservatives, or any funny fake stuff. It should be eaten within a day or two before it goes stale.  Take comfort in knowing there’s nothing artificial in there keeping it fresh. (and it also gives you another perspective of what they must put in store-bought bread).  If by the 2nd day we haven’t eaten it up, I slice it into pieces that will fit in the toaster then freeze. Then toast it straight from the freezer and it’s like ‘just baked’.


Starter or Sourdough Starter (Culture, Mother Starter)

  • A starter is a mix of flour and water that naturally ferments due to wild yeast organisms in the flour itself and also in the environment which drop into the jar.  The wild yeast feeds on the flour (with the presence of water), and creates fermentation.  A by-product of fermentation are acids and alcohols, and carbon dioxide.  The acids and alcohols give the starter that twang taste, and the C02 gives it the air bubbles.  This science thing is what we call ‘natural leaveners’.  When the wild yeast is feeding, it doubles, triples, quadruples in size which makes your bread rise. It releases C02 which makes a light and airy interior, and the acids and alcohols give it that signature twang taste.
  • You’ll need to feed your starter to keep it alive – and it can survive for decades with minimal attention.  But because a starter doubles every time you feed it, over time you’ll end up with a boat full of starter.  Unless you’re running a professional bakery, you’ll want to find other uses for your starter:  making other things, composting it, or giving it away.
  • To bake a loaf of sourdough – you’ll use some of this starter (surprisingly little), and mix it separately with flour & water.  That separate mix will go directly into your bread dough.  It’s called a Leaven.  You’ll set aside your main starter to use another time.
  • A brief word about yeast & salt. We’re all taught salt will kill yeast so never allow them to touch and add them separately. Some bakers will tell you this is a beginner’s mistake. Hmm..maybe not so fast. While pouring a pile of salt on the yeast and letting it sit will probably hurt the yeast – there really isn’t much damage done to add salt and yeast together, then quickly mix into the dough. Why do I say that? Because there’s research. Interesting baker’s research comparing loaves with salt & yeast separately, and loaves with salt & yeast together. Almost no difference. Nada. So while I don’t think the salt/yeast controversy is really myth busted – I also don’t purposely dump the salt on top of the yeast and walk away – I just mix it in and it’s fine!  For more advanced loaves – I usually do mix separately – only because the dough is already tricky to work with and I want to give the yeast the best possible shot at performing well.

Levain (or leaven)

  • Made with an amount taken from the starter, and adding flour and water.  This little mix is called the leaven and will go directly into your dough at the proper time.  It will be what makes the dough rise.  It’s ‘naturally leavened’ or ‘wild yeast-leavened’ because it’s all-natural and doesn’t use any commercial yeast. Before you add the leaven to the dough mix, it must be given time to ‘build’.  Building is allowing that starter to feed on the flour & water you gave it, as the wild yeast feeds, it will ferment, create C02, acids, and alcohols, and will double in size (just like your original starter when you feed it). But the leaven is destined for the loaf of bread you’re making – that’s it’s purpose.
  • The leaven will tell you when it’s nicely built and ready for your dough mix. It will have changed from a dense, pasty mix (when you first mixed the starter with flour & water), and transform into a pillowy and light mixture, with some bubbles around the sides and the top, and has doubled in size. Again, that’s the fermentation & the Co2.
  • The ‘build’ takes anywhere between 2 to 4 hours, maybe 5 hours. It all depends on the temperature of your kitchen. Cooler temps (below 70F) will take longer. Warmer temps (above 78F) will be faster.  A sweet spot is around 75-78F.
  • The strength of your build also depends on the ‘strength’ of your original starter. If you use a starter that was originally underfed or neglected (it happens to all of us), then the leaven will do more poorly.  If your starter is well-fed, as in the night before, your leaven will be strong. Like a marathon runner that bulks up the night before…they’ll perform better the next day.
  • The last (probably not least) thing that affects your build is the type of flour(s) you’re using in the recipe.  Finely milled flours like bread flour are pretty quick to react and build and there’s plenty of protein in the flour to give it strength.  Whole grain flours (wheat, rye, spelt, etc) might take a bit longer.


  • Autolyse (“auto-lease”) is one of the first steps in the baking process where only flour and water are mixed together, that is the dough mix flour and water (not the leaven).  By mixing the flour + water early on in this autolyse phase, it immediately starts enzymatic activity (the water draws out sugars in the flour) and with hydration, the cell structure of the flour relaxes and becomes more absorbent.  As simple as this is – these 2 things create a successful path forward by increasing the extensibility and strength of your dough.  Both very good things.  Extensibility allows the dough to expand and fill with gasses (air pockets) that result in a springy, light, and airy middle. An autolyse generally takes roughly 30 minutes and longer, usually in the hour to 2 – or even 3 hours in typical situations.
  • So you tell yourself: well, if autolyse builds extensibility and that creates a nice rise and light texture, then let’s just autolyse the heck out of it and start it way early or even the night before. Longer might be better, right? Hmmm… no, not necessarily. For some dough mixes that call for heavy flours (whole grain, stone ground, ryes, kinds of wheat, etc), then a bit longer autolyse could help because the dense flour’s cell structure could take longer to absorb the moisture.  But, there’s a risk here.  Allowing too much time for that flour & water mix to sit, could create too much acidic activity and too much absorption, which takes the flour too far.  The acids degrade the strength of the cell structure and the mix loses it’s structure entirely. It poops out, becomes flaccid, runny, it pours on the counter – it’s what we call ‘dead dough’. There’s no getting it back – but it makes great pizza dough!
  • In certain situations, I will do a longer autolyse because I’m using denser flours – usually mixing it at the same time I put together the leaven. Two birds, one stone & convenient.  (I don’t mix ALL of them together in one bowl). The leaven is building in its jar, and the autolyse in its bowl, both happy campers and I’m free for about 4 hours (again, depending on the temp of the kitchen).

Bulk Fermentation

  • This is an essential step (they all are, really) that allows the dough time to transform from a tight gloopy mess into a lovely silky, airy dough. Depending on the temp of the kitchen, it will take anywhere between 4 -5 hours. You can think of this as a replacement for kneading. My beginner recipe, and most sourdough recipes, don’t really call for ‘kneading’.  Instead, we allow for fermentation and some working of the dough in very brief periods to build strength & elasticity.
  • The bulk fermentation is usually divided into 2 phases.  In the 1st phase where a series of short, brief manipulations are done, with time in-between to allow the dough to ‘relax’. And a 2nd phase that allows the dough sit undisturbed (covered) letting the C02 to build and create rise and air bubbles, and also the acids & alcohols to develop further to give it the twang and delicious taste.
  • Once you get your sea legs – you can fool around with this fermentation phase to tailor it to your personal schedule. You’ll discover certain steps don’t have to be exactly timed and you can get to it whenever or even stall out the whole process and put it in the frig if you have to bail on your dough because life gets in the way. For now, though, it’s important to learn the general process as simply as possible. I want you to get a great loaf of bread, so follow along with me as I’ve laid it out and down the road, we can make this your own.


  • A proof phase in sourdough isn’t the typical proof you think of with regular pan bread where you punch down the dough and let it ‘proof’ to double in size.  A sourdough proof happens after the dough is snuggly in its banneton (or linen-lined bowl).  You’ve already been through the bulk, then pre-shape, then shape – and now it’s time for the Proof.
  • Proofing is leaving your dough to rest for 30 minutes to an hour at room temperature, then finishing the proof in the refrigerator overnight – or up to 2 or even 3 days (3 days is pushing it).
  • Proofing on the counter at room temp is called ‘counter proof, or bench proof’.
  • Proofing in the refrigerator is called “Cold Retard”.  It’s still proofing, fermentation is definitely still happening, but it’s slowed down because of the cold temps. The result is a light but cohesive and strong dough that is easy to turn out and score. A cold retard is SO much easier to work with and it develops incredible flavor.  However, if you have to bake right away and can’t do the overnight thing – then you can counter proof for a few hours, then bake straight away.  Expect the dough to be more slack when handling it (getting it out of the proofing bowl or banneton) and it will probably spread out pretty quick before you get it into the dutch oven. Just work quickly and all will be well.  You’ll still get great spring and lovely bread.  For beginners though, I recommend a cold retard. It’s just easier to handle. Don’t expect a cold retard to double in size in the refrigerator. It might not look much different than when you put it in last night.  When you flip it out of the bowl you might think – huh, this thing is dense, cold, not sure about it. But it will work! That cold dough gets in the hot dutch oven and steam bursts out of the dough, making a great ‘spring’. It all works out in the end.

Baker’s Math – Baker’s Percentages

  • I was told there would not be math, and I still don’t do this math. Like most people, I use a calculator for math and when doing baker’s math I use Baker’s Math Calculator or a Hydration Calculator. They can be found online, simply plug in your numbers and it calculates the percentages and hydration. Thank god.
  • Baker’s math and percentages are important to understand though because with sourdough we often don’t refer to “recipes” but rather percentages we use to scale up and down depending on how much bread we want to make. We also want to know the hydration of the dough.  (To give you a reference – store-bought white or wheat bread is probably 65% range while homemade sourdough is usually 72% and up.  The higher the hydration the trickier it gets and it affects the structure and bake of your bread).
  • The flour is always expressed as 100% and all other ingredients are expressed as a percentage of the flour weight.  Those numbers always add up to 100%.
  • Hydration is simply the percentage of water to flour. An example below:

1000g flour = 100% .   Then, if you add 800g of water to the flour you get an 80% hydration rate.

  • This is how it works in my simple brain but there are many resources that will give you all the details on percentages and how to scale up and down. Check out my sourdough resources post for a list. I provide links to smart people’s websites and calculators. Many of them are on my Insta DM speed dial and they’re always available to help with my math questions.
  • An excellent baker’s percentage calculator can be found here:
  • A side word about hydration:  While it’s important some people make sourdough all about hydration. IMO it shouldn’t be that way.  Sourdough should be about a loaf of bread that tastes good to you.  That’s it.  Bottom line.  If you’re doing a 72% hydration loaf & you like it – but you see one out there that’s 92% hydration – that doesn’t make their loaf better than yours.  It might be interesting to experiment with higher hydrations and as you get more experienced you’ll probably do that, but just be comfortable with where you’re at enjoy the process and your loaf of bread.


  • Windowpane is a test to see how much extensibility you have in the dough and if the bulk fermentation phase is done and you’re ready to move on to the pre-shape.  It’s where you carefully pull up a segment of your dough and stretch it outward, stretching it thin, going slowly, and you’re looking for the section of dough to become thinner and thinner, being able to stretch enough to literally see through it a bit – without it breaking.
  • Windowpane isn’t a mandatory test, it’s just a guide or a sign. Most times with the bulk is done you will get a windowpane if you try one. Sometimes, you’ll get a windowpane just from the autolyse alone, and other times you’ll never get a windowpane at any point. It just depends on the flour(s), temperature, hydration. Generally speaking though, and for my Beginner Tartine recipe, you probably should achieve a windowpane at the end of Bulk.



Stretch & Folds, or Coil Folds, or other slap methods

  • The process of building extensibility into your dough. When the dough is in the bowl (or some methods call for it to be in a pan, or on the counter), it’s briefly manipulated by stretching it and pinning that stretched portion to the opposite side. Mentally dividing the bowl into quarters and doing a stretch and fold for each quarter.  Then let the dough rest at least 30 minutes before doing another series of stretch and folds. Usually, most methods call for a series of 3 stretch and folds but it can extend to up to 4 or 5, depending on the extensibility.


  • Is done after the bulk ferment is finished. Turning out the dough to a lightly floured counter (or some people use a counter spritzed with water), doing a letter fold, trying to keep in the air that’s developed from the fermentation, flipping the dough over, cupping and spinning in a circle to create a nice boule (round) shape…tucking it slightly into a batard (oblong) shape, then letting it rest.


  • Done after the pre-shape.  Flipping the dough back over so the smooth side is down and the seam side is up. Either doing another letter fold, or doing a circular pull and pin (your choice), but tightening up the dough ball and creating tension – while at the same time trying to be gentle with it and not totally de-gas it.  Then pulling the dough along the counter to create more tension, and manipulating into the shape you want – either a batard (oblong)  or a boule (round).

The Bake

  • This one’s obvious – but some people adjust their bakes. They’ll bake with the lid on at really high temp, then take the lid off just 20 minutes in and continue to bake with the lid off.  Other people bake with the lid on for the majority of the time, then take the lid off towards the end. For my Beginner Tartine recipe, I do the latter as it’s a bit easier to predict the bread won’t over-brown.  For my own bakes, I usually take the lid off after 20 min, will check the spring, maybe put the lid back on for a few more minutes. Then with the lid off, I’ll create some additional steam in the oven by pouring some hot water into a pan below the dutch oven to finish baking. The steam creates a thinner, more flaky crumb.


  • Whether you slash or score – totally up to you.  I do one or the other depending on my mood.  If I do a slash, I usually don’t apply much rice flour and just leave the loaf a’la natural with a single slash.  If I do a score pattern, I’ll use some white rice flour sprinkled on top to bring out that pattern of the score.


Bread Qualities – How to judge a good loaf of bread.

What makes a good loaf? The flavor and texture YOU like. That’s it. Bottom line. However, bread people out there have created a reference list and this is what I look for…some of my personal benchmarks.


  • A distinct tang, some nuttiness, a hint of fruit or maybe beer, an undertone of salt. The flavor will depend on your flour(s) and bulk ferment time.


  • Everything on the exterior. Crispy, crunchy, thin & not leathery. Flaky.


  • Personal preference from blond to a deep caramel. A variation in color is generally sought – with caramel color on the surface and blond dough peeking through the score or slash.


  • Everything inside the crust. Light, pillowy, with a presence of holes created by the fermentation process. Not gooey or gummy but a bit chewy and when pressed with a finger bounces back out.


  • The rise and lift. A sign of balanced percentages, a healthy sourdough starter (and leaven), properly worked, and fermented dough. And definitely a sign of properly built tension during the Shape phase.

Ear and Bloom

  • When scoring, a sign of a proper quick slash movement to slice the dough rather than ripping it – this, along with the correct depth and angle of the blade, will create an ear with a nice ledge.  The bloom is where the gluten strands have stretched during the quick rise & steam while baking. It’s in the interior part of the ear, baked crispy strands of dough.


  •  A sign of a well-hydrated and baked loaf at a proper oven temp.

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