Notes on sourdough

2020/04/12

And now for something completely different… sourdough! I first began baking as an escape from grad school ennui. Since then, and especially in last couple months, it’s been fun to share a few of the tips and tricks I’ve picked up along the way with friends who are just getting into baking.

The notes that follow document some of what I’ve learned. Of course, they’re a work in progress and I’m learning more every time I bake. But maybe you’ll find them useful. I’ve split this post up into two sections: “TL;DR” walks you through the essential steps to making sourdough. If you want more, “More detail, please” delivers with some extra flavor, so to speak.

TL;DR

  1. Get some starter and the rest of the ingredients. The easy way to get sourdough starter is to borrow from someone who already has a healthy one. The less easy (but not that difficult) way is to make your own. See the “starting a starter” in the detail section if you want to try.

Once you get some starter, you’ll need the following ingredients (makes one loaf):

Ingredient Amount
Water 350 + 25 grams
Starter 100 grams
Unbleached flour 450 grams
Whole wheat flour 50 grams
Salt 10 grams
  1. Mix your ingredients (except 25g of water and the salt) until fully combined in a large bowl that you can cover with plastic wrap or a lid. Cover and wait 30 minutes. Mix in the 25g of water and salt.

  2. Fold / Bulk Fermentation. For the next 4 hours, you’ll “turn” the dough every 30 minutes. To turn the dough, reach underneath, pull it up (stretching it out), fold it over itself, rotate, and repeat (example video here). Do this a few times (covering the dough in between). During this process, the dough will become smoother and begin to expand, which is why this step is also the bulk fermentation.
  3. Shaping. After the bulk fermentation is complete, you’ll shape the dough. This means you’ll form it into a ball shape and pull it across your tabletop to create tension in the dough (example video here). Wait 30 minutes (cover the dough), and do it again.

  4. Second rise. Put the shaped dough into some kind of bowl lined with a floured linen cloth. Wrap it with a towel or two to limit dehydration, and put it into your refrigerator for 12-18 hours. This is the second rise.

  5. Bake. Put your cast-iron dutch oven (or whatever you’re using to bake — it should have a top) into the oven and let it heat up with the oven at 500 degrees. Then, pull the dough from the fridge, remove the bottom of the dutch oven from the oven and carefully roll the dough into it. Slice the top of the dough with a razor to let steam escape, and put it back into the oven with the top on. Lower the oven temperature to 450 degrees, and bake for 15 minutes. Open the oven, remove the top, and bake for another 20 minutes. Turn off the heat, crack the oven about 6 inches, and wait 30 minutes to set the crust. Then pull it out and FEAST.

How’d it go? If you found these notes useful, send me a picture of your bread! I’d love to see it. Want more details? Read on!

Gimme allll the details

I love the process of working with a live yeast culture to produce something edible. And bread is one of those rare items that defies typical economies of scale: with a little work you can produce a better, cheaper product than you can buy at almost any grocery store. But, as a home baker you have to approach many of the challenges of bread-making differently than someone with a commercial oven would. Figuring out how to get an open, moist crumb, a strong crust, and that delightful sourdough flavor out of conventional tools is a neverending journey. These tips document that journey.

Timing

Making bread timing work for you is one of the key aspects to ensuring that this becomes a sustainable habit.

  • I’ve found that starting around 5pm lets me get to bed on time and allows me to bake either the next morning (for a less sour loaf) or the next afternoon (for a more sour loaf).
  • Alternatively, if you want to have a sour loaf in the morning, I would consider starting the morning before and letting it set from noon until 8am the next day.
  • Once you get used to the pattern of the bread, you can play with the timing to get it to fit your schedule. For instance, you can accelerate the process by letting the dough spend more time outside of the refrigerator, and vice versa.

Starting a starter

  • To start a starter, mix 50/50 whole wheat and white flour together. You’re going to use a bunch of this mixture, so you might as well put together a lot of it. Tartine suggests five pounds.
  • Mix a handful of flour blend with water with your hands in a clear bowl (plastic or glass). It should have the thickness of a thick batter – no lumps. Leave it for 2-3 days.
  • If you have bubbles, you’re ready for the next stage. If you don’t have bubbles, wait another day or two. It’s fine if there’s a crust – just remove it.
  • Now you’re going to start feeding it. Discard most of the culture, and add the flour mix and water in about equal weights (50 grams each or so). You want a thick batter still. You’ll do this for a couple weeks or so. Initially the starter will be fairly stinky. That should get better and it should smell more sweet/ripe later on. You want to feed it every 24 hours or so.
  • You’ll know the starter is ready when the smell is more yeast-like and when it ferments predictably. This means that it should rise 6-8 hours after you feed it and be larger in size. Then, you’re ready to mix.
  • Whole grain or rye flours are better for getting started. This is because they have more enzymes available for helping the yeast to break down the carbohydrates. As the starter becomes healthier I move toward more AP flour. More whole grain or rye in the mix leads to a richer sour flavor.
  • Thin (more watery) starters work faster. This is because the water helps the yeast and bacteria break down the flour more quickly. They tend to have slightly less sour flavor.
  • Thick (more floury) starters work more slowly and seem to demonstrate their rise better. They tend to create a slightly more sour flavor. I almost always prefer to have a thick starter.
  • Both bacteria and yeast create CO2. Bacteria is responsible for the lactic and acetic acids that give sourdough it’s distinctive flavor.

Mixing

  • You usually want to use a starter that you fed 6-8 hours ago, where it’s still gassy and has doubled in size. To get this, discard most of it (down to 20-30 grams, or about a tablespoon) and add 100 or 200 grams each of flour and water (100 if you’re making one loaf, 200 if two). After about 10ish hours it should be ready to bake. It will smell sweet like an overripe fruit — this is what the Tartine guy calls a young leaven, before it has become vinegary. This should pass the “float test” — if you stick a bit in a bowl of water, it will float to the top.
  • Using your chosen recipe (see bottom for mine), put in the (warm) water first. Then add the starter. It should float. Finally, add the flour and anything else except the salt. Mix it all together (I like to use a long-handled spatula but your hands are fine).
  • Next you’ll cover it for the autolyse period. The autolyse is the 30-60 minute period after mixing the starter, flour, and water but before including the salt. It lets the yeast get started. The salt slows down fermentation (by dehydrating the dough) but has important qualities in gluten formation. I make this easy on myself by putting the salt in at the beginning (with a little more water) but not mixing it together right away.
  • After the autolyse is over, scrunch the dough through your hands to mix the salt all the way in. Now wait 30 minutes and begin the folding process.

Folding (and bulk fermentation / first rise)

  • Folding is the equivalent of kneading for sourdough. Both accomplish the same goal: encouraging the development of a strong, flexible gluten structure in the dough. But kneading is more appropriate with artificial yeasts, since they ferment so aggressively. For natural yeasts, folding is gentler and still allows for proper structure formation.
  • There are people who think that folding is not necessary, or at least has minimal impacts on the dough. They may be right.
  • Gluten and starch are the main parts of flour.
  • Gluten, which is basically chains of proteins + water, forms when flour and water mix.
  • Folding helps the dough develop strong, flexible gluten chains.
  • Relaxing allows the tightest chains to break
  • Gluten (along with a little natural fat/lipids in the flour) capture CO2 from fermentation.
  • More gluten means higher volume. But too much gluten will taste gross.
  • You are done folding/kneading when the dough is strong but flexible. This takes a bit of practice to judge.
  • The dough tends to go from lumpy and shaggy to smooth and almost shiny. It should stretch but not rip.
  • It is possible to overmix: this can lead to a sudden, total breakdown of the gluten.
  • In the process I use, the dough is effectively conducting its first rise during this time. For other types of bread, the folding and first rise are separate steps.
  • Stretch and fold demonstration I
  • Stretch and fold demonstration II
  • After folding, I let the dough finish rising for an hour at least, and maybe a few hours more, to get more fermentation going.
  • This video has a good description of the whole sourdough process, including how to know when to finish the first rise.

Shaping

  • Shaping is the process of giving shape to the dough.
  • In the shaping process, I first fold the dough over itself (four corners technique), and then drag or push it along the table surface I’m using to help develop strength and tautness in the surface. This is far easier to see through video than it is to learn through text.
  • Lots of ways to shape
  • Goals of shaping
    • Remove excess gas.
    • Spread gas throughout the dough.
    • Create an even loaf.
    • Create a strong, tight surface to capture more gas as the dough continues to rise and to encourage more lift in the dough during the oven spring (see Baking section).
  • Guidelines for shaping
    • Touch the dough as little as possible. When touching the dough, keep hands floured.
    • Use only a little flour on the table. Important to maintain some friction between the dough and the table to encourage tautness in the surface.
  • I shape twice, with a 30 minute rest (covered) in between.

Proofing

  • After shaping the dough a second time, I put it into a banneton that’s been amply floured with a mix of wheat and rice flour (these seem to be better at releasing the dough later).
  • I usually put a linen cloth in the banneton before putting the dough in it. This isn’t required (and means that I don’t get the nice banneton lines that you’ll see on some breads), but it’s much more difficult for even the wettest doughs to stick to linen.
  • I cover the dough, usually with another linen cloth, maybe a layer of saran wrap (to keep moisture in) and then a kitchen town, wrap a rubber band or two around it, and put it into the fridge.
  • I let the dough proof in the fridge for at least 12 hours before baking. Sometimes, if I want an especially sour flavor, I let it proof for 18 or 24 hours. This overproofs the dough a bit and it doesn’t rise as well, but I slightly prefer the more-sour flavor.
  • Alternatively, I’ve also experimented with moving shaping later in the process. In this case, I finish mixing and then put the dough (in its container) into the fridge for about 12 hours (usually overnight). I think pull it out, let it warm up a bit, and then shape. It goes back into the fridge again for about an hour while the oven pre-heats and then I bake. This seems to give me more tension in the dough as it bakes, and a better rise than shaping before it goes in the fridge. However, I haven’t been able to get quite the same sour taste. A work in progress!

Baking

  • I bake the dough in a cast iron dutch oven, using the smaller part of the dutch oven (what would normally be the lid) as the base. The larger part of the dutch oven (what would normally be the base) is the top. The purpose of this is to preserve moisture for the first part of the bake. There are other techniques one could use, such as including a pan of water for the first part of the bake. But this is the easiest for me.
  • I preheat the oven to 500 with the dutch oven inside.
  • I remove the dough from the fridge and score (slice) it with a razor blade to give the gas a path to escape. Otherwise the dough explodes in an unsightly way.
  • Turning the banneton upside, I drop the dough gently into the smaller part of the dutch oven, just removed from the oven. I put the larger part of the dutch oven on top of it and put it into the oven, turning the temperature down to 450.
  • I bake it for about 15 minutes covered, remove the cover, and bake it for another 15-20 minutes until there is a nice browning on the crust.
  • Finally, I pull it from the oven and let it cool on a rack.
  • I don’t generally cut into the bread until about an hour from when it’s left the oven.

Tartine Country Loaf Recipe (makes 2 loaves)

Ingredient Amount
Water 700 + 50 grams (covering the salt)
Starter 200 grams
White flour 900 grams
Whole wheat flour 100 grams
Salt 20 grams
  • You can find the NYT version of this recipe here.

Modifications

  • I currently make a whole wheat country loaf. This has 600 grams of whole wheat and 400 grams of white. It doesn’t rise quite as well but the flavor is better and it’s better for you.
  • I usually only make one loaf at a time. So I halve everything above.
  • I don’t do a preferment or a poolish (yet), but am planning to try it soon.

My favorite bread books

  • Flour, Water, Salt, Yeast, Ken Forkish
    • Forkish’s treatise covers all kinds of bread, both naturally leavened and non. If I had to recommend a single book, it would be this one for both its variety and accessibility.
  • Tartine Bread, by Chad Robertson
    • I learned to bake sourdough from this book. Their starter method and their country loaf recipe are still my rough templates. The book is definitely verbose and, let’s be real, a bit pretentious, but there’s no arguing with the quality of their product (if you’re ever in San Francisco, stopping by the Tartine bakery or manufactory is a must). They’ve written at least two more books since
  • bread science: the chemistry and craft of making bread, by Emily Buehler
    • Very useful to get down to the basic chemistry of bread-baking. The later chapters are more generally accessible and provide useful guidance on almost all stages of the baking process. Not specifically focused on sourdough, though.