Commercial "baking" yeast is a single kind of organism that belches a lot of gas really fast. Sourdough is two organisms, wild yeast and bacteria, in symbiosis. Together they transform the grain to make it more healthful, more digestible, and also resistant to getting moldy or stale. Many people with wheat allergies or yeast allergies have no problem eating real sourdough.
How Does It Work?
With sourdough, you are keeping and feeding a population of friendly yeast and bacteria, called a "culture", or a "starter". The population rises and falls, depending on where you keep it and what you feed it. When you make a loaf of bread, you are carefully managing a population explosion. The sour flavor comes from acids made by the yeast and bacteria, and when it gets really strong, that does not mean the sourdough is strongly active, but that it is depleted, that the population has already eaten its food and collapsed.
What You Need
. Most grains will work, though only wheat has enough gluten to hold together big air bubbles and make a fluffy loaf. I use a mix of whole wheat or whole rye flour and white flour.
. It will work better if the chlorine is taken out, either with a carbon filter, or just by setting it in an open container for a day or so.
to keep your sourdough in. The wider the mouth, the better. Glass is ideal for sourdough. Pottery is good too, and probably wood. Metal is not good because it reacts with the acids. Stainless steel is okay for mixing bowls for utensils.
Bowls and Pans
, depending on what you're making.
or at least a stove.
Some people have sourdough cultures that are more than 100 years old. I wonder how the yeast and bacteria have changed in that time, whether they're getting domesticated, losing their edge. So I like to catch a fresh culture now and then. Catching sourdough is easy! Books make it sound like it's difficult and complicated and takes a long time. Using the following system, I have never once failed, and it usually takes less than three days.
Mix equal volumes of good flour and good water, and set it in a glass jar in a warm place. Some people say to keep the lid off so yeast falls into it from the air, but evidence suggests that the yeast is already in the flour, so I just put the lid on loosely so it can breathe. A loose lid is easier than cheesecloth and works just as well. If you do keep the lid off, put it on a high shelf where less bad stuff will fall into it.
What you've got now is a race between good and bad microcritters to take over your jar of food. If the sourdough wins, it will smell sour, probably with a layer of brown liquid on top, but not moldy or rotten. If it gets moldy or rotten, it's almost certainly because you're using low quality flour or water. If it doesn't do anything, it's probably because of irradiated flour, chlorinated water, or a location that's too cold. Rye flour is said to work better for starting the yeast, and then you can switch to a different flour if you want. Another trick is to put it in a warm place, but not above body temperature. Another trick (don't tell anyone) is to add a tiny bit of your saliva.
I've heard that you can catch different strains of wild yeast and bacteria that behave differently, but I've done it many times and never noticed a difference. If you add commercial yeast, you'll just get a culture that's dominated by commercial yeast and not sourdough yeast. I've heard that you get something good if you use the white mold that grows on grapes.
So: flour, water, jar, wait a couple days, it turns sour. By the time you're sure that your jar has been taken over by the good stuff, it will be much too depleted to use. So you need to dump out almost all of it, and add fresh flour and water, again in roughly equal amounts, and stir it well. Then it will rise, and be good enough to use, but still not as good as it will be after one or two more cycles (see below).
After you've caught the right yeast and bacteria, you want your jar of flour/water to get bubbly and increase at least 50% in volume. If it doesn't bubble, smell it. If it smells like nothing, or like flour, it needs more time and warmth. If it smells really sour, but isn't bubbling well, refresh it again: throw out all but a little bit and add more flour and water.
What you're aiming for is a jar of what I call peak
sourdough. It's also called levain, or a sponge. The purpose of the sponge is not to make air, but to grow a higher yeast population, and also to give it more time to transform the flour. When it's at its peak, it has risen to maximum volume, it's full of living yeast, it's thick enough to hold air bubbles, and it's not yet very sour. That's when it's perfect for eating, or for going to the next step if you're making bread. When it passes its peak, it falls in volume, the bubbles go out, the yeast population crashes, and it gets too sour -- too much acid and not enough sugar.
Past-peak sourdough is great in a pie crust or anything leavened with baking powder, but it's difficult to use it for bread. You have to add a lot of flour and water (compared to the quantity of sourdough) to dilute the acid, and then wait longer for the next rise. Do not mistake sourness for rising power! The surest way to get your bread to rise is to build up to it, with good bubbly rising at every step.
Taking Care of Sourdough
It's not as hard as a baby, or even a dog, but it requires more attention than a plant. It's a bunch of tiny living animals that need frequent food. If you neglect them, they'll eat up all the food and die down to almost nothing, and possibly other organisms will take over. But the nice thing is, they do everything slower at lower temperatures. Unless you're eating sourdough at every meal, or your kitchen is cold, you'll need to keep it in a refrigerator.
To feed it, remove almost all your sourdough (ideally you will eat it) and add more flour and water to what's left in the jar. Some people say to remove only half but this not only gives you less sourdough to eat, it leaves an overly sour acid bath for the next batch. You can remove 99.99% and your sourdough will still be alive -- it will just take a long time to build its population back. I remove about 90% -- I just dump it out and leave in whatever clings to the sides of the jar.
When you add the flour and water, you'll have to learn through practice how thick to make it, depending on your flour. Some flour gets thicker after it soaks in water, so you have to start it runnier, and some flour gets runnier so you start it thicker. When it's done, if you need a spoon to get it out, it's too thick. If you're getting a layer of water, it's too thin. Also, as you'll quickly find out, you should only fill the jar about two thirds full, to give it room so it doesn't explode or run out everywhere. I always add the water first, and shake up the jar to evenly distribute the dregs of living sourdough, and then add the flour. And if I'm making bread that's part whole wheat and part white, I add the whole wheat now, because whole wheat contains stuff that's easier to digest if it's been soaked.
It will often happen that you don't use your sourdough in time and it gets flat. The only thing to do is "reset" it: save a little bit, feed it fresh flour and water, and throw the rest out, or use it in something other than bread. You can save sourdough that has been neglected for a long
time. Even if it's turned black on top and smells totally nasty, there's probably still some living yeast in there. Take a bit out and feed it fresh flour and water, and see what you get. And if it's dead, just catch a new one.
Zen And The Art Of Sourdough
Sourdough exercises your foresight and awareness. For example, at noon, I anticipate that I will make a waffle at 10PM, and I know that I used and fed the sourdough last night and put it straight in the fridge, so it's nowhere near ready. If it's a hot summer day, I should wait until about 6PM to take it out, but if it's cold I need to take it out now to give it all day to get to its peak. If I need it fast, I'll put the jar in some warm water. Another trick is to leave it out, bring it mostly to its peak, and then (if you remember) put it back in the fridge, where it will remain ready to use for maybe a day. The point is, you have to devote a permanent bit of attention to where your sourdough is in its life cycle.
Sourdough Pancakes and Waffles.
I just take sourdough that's right at its peak, and pour it straight on a hot oiled pan or waffle iron. That's it! If you want to mix in other ingredients, or if you stir it at all, you will pop the bubbles and you'll have to stir in some baking powder to get it to rise enough. A waffle, because of the greater surface area, is more forgiving than a pancake. Even when I do it perfectly, my pancakes are a little gummy, but imperfect sourdough can still make excellent waffles. You'll be surprised how good it tastes with nothing but flour, water, and friendly microbes. Put on some pasture-raised butter and real maple syrup, and you've still spent less money than with white-flour white-sugar aluminum-baking-powder hydrogenated-oil restaurant pancakes. Almost any kind of flour will work.
These are the next easiest thing. You still don't even need a bowl. Clear a space on the countertop or a big cutting board, pour some flour down, pour some sourdough on top of it, mix it with your fingers, fold it over a few times, add some more flour, and roll it out with a rolling pin or wine bottle. It will take some practice to get the proportions right and keep it from sticking. The more gluten is in your flour, the easier it is. With anything but wheat, you'll have to settle for very small tortillas.
Sourdough Pie Crusts.
If you want a light, flaky crust, forget sourdough, and see my recipes here
. A whole grain sourdough crust will not have light texture, but it will have more interesting flavor and be better for you. I recommend a mix of white flour and whole wheat pastry flour. Whole wheat bread flour is slightly easier to work with but the crust will be brick-like, and non-wheat is so fragile and sticky that I wouldn't even try to roll it out, but just press it into the pan.
In a bowl, cut some butter into some flour. You can use your fingers, a pastry blender tool, or my new favorite method is to use frozen butter and a cheese grater. Most recipes call for a whole stick or more, but if I'm eating lots of pie, I might use as little as half a stick. For vegans, I recommend palm or coconut oil, or no-trans-fat margarine, which is common now. Liquid oil works too, but you'll probably have to roll the crust out between sheets of waxed paper. Just dump the oil in at the same time as the sourdough.
Now add the sourdough. Two cups (16oz, half a liter) of bubbly sourdough should be enough for a two-crust pie, or more than enough for a single crust. Mix it in with the flour, don't work the dough too much, get it firm but pliable, and roll it out with more flour. Pie crust is not easy! For a lot more info, check out my pie crust
In a bowl, cut butter or other solid oil into flour, then mix in one or two teaspoons of baking powder, maybe a half teaspoon of baking soda, and dump in the sourdough. It's basically like a pie crust, except you need baking powder/soda to make the biscuits rise. Have your oven already heated and your pan already oiled, and when you add the liquid stuff to the dry stuff, mix it quickly and gently, fold it over a couple times, and form the biscuits. I either make a fat disc and cut it into six wedges, or if the dough is too sticky, I just drop six gobs of it in the pan. Bake it at 350-375 F for 20-30 minutes.
Other Soda Breads
can be made by varying the biscuit recipe. For example, to make scones, add sweetener. For blueberry muffins, add sweetener and blueberries and cook them in a muffin pan. For banana bread, add some mashed up bananas and maybe walnuts, and make one big thing instead of several little ones. For most of this stuff I'd increase the baking powder to a tablespoon -- it's full of sodium but it's your insurance against the bread coming out wet and gummy.
I now use a method based on the one at The Perfect Loaf
. That site has some helpful photos, but the excruciating instructions make me want to have nothing to do with bread. My goal is to keep it as simple as I can get away with. I don't measure, I don't use a thermometer, and I still get nice loaves.
First, you need a good quantity of good sponge. If I'm going to make bread the next day, in the evening I'll take my jar of dregs out of the fridge, add some filtered water and some flour, stir it well, and set it in a cool place all night. It will take some practice to get the time and temperature right, so that when you're ready to make the dough, the sponge is bubbly and only slightly sour.
I like to add all the water that I'm going to add, in the sponge, so that when I make the loaf I just add more flour, plus salt and other stuff.
There are all kinds of options for flour. The easiest is just regular white flour, a.k.a. all purpose flour. It kneads smoothly and holds lots of air, but it also has the least flavor and nutrition. The next easiest is whole wheat bread flour, and then wheat ancestors and other grains. As you go down that road, the dough becomes stickier and harder to work, and the bread becomes denser, but better tasting.
I like to use a blend of difficult flour and white flour. If you're going to use any white flour, it's better to put it in closer to the end of the process, because whole grain flour benefits more from fermentation. So for the sponge, I might use whole wheat bread flour, or rye, or spelt, or einkorn, a nutty and sticky ancient wheat. Then for the loaf, I'll add more of that plus some white flour.
I just pour the flour on the countertop, pour the sponge over it, throw on some salt, and start kneading. There are different kneading techniques, but the important thing is that you repeatedly fold the dough over on itself.
It's better to start too wet, and gradually add flour, than have the dough get too dry and have to add water. There's no easy way to know when to stop adding flour, or when to stop kneading. Some recipes say it's when the dough feels silky, or when it cleans your hands, but unless you're using a lot of white flour, you'll never get to that stage, or you'll get there by making the dough too dry.
I like to knead for about five minutes, and have the dough be somewhat sticky and somewhat firm, maybe halfway from a gooey mess to a rubbery ball.
The next stage, which I got from my sister, who got it from the perfect loaf guy, is delayed stretch-and-fold. This is basically very slow kneading. The point is to get more air in the loaf, and more stretching of the gluten, in a gentle way that gives you bigger and lighter dough before the final shaping.
Put the dough in a lightly oiled bowl, and let it sit for maybe half an hour. If you're doing it right, it will rise, not double, but enough that you'll notice. If it doesn't rise, try waiting longer.
Now, rather than using more flour to keep it from sticking, wet your hands, and very gently take it out. Let it stretch, fold it over, then let it stretch another way and fold it over, three or four folds total, then put it back in the bowl. Wait about half an hour, and do it again. After you've done this about three times, put the dough in whatever pan you're going to bake it in.
First, rub the pan with oil and then dust it with flour. I use coconut oil and white flour. A rectangular loaf pan is good for sandwich bread, but a round pan, like a pie pan, will give the dough more room to rise.
The final rise is also called the proof. How long it takes depends on a lot of things, including the temperature, the vigor of your yeast, the density of the loaf, and the amount of salt. As with the sponge, what you're aiming for is the point where the yeast has eaten its food and transformed the dough and made lots of bubbles, but it hasn't started declining, which will make the loaf collapse because the air bubbles are no longer being filled. White bread might double in volume but whole grain probably won't increase more than 50 percent.
Now you put it in a hot oven, where ideally the warmth will give the yeast one final push of growth, and then the heat will expand the air bubbles and fix them in place in a not-too-dense loaf. I like to start at 425F, then turn it down to 400 and bake 30-40 minutes. Professional bakers go much hotter and also use steam. A trick for making a regular oven steamy is to put a pan with a little water on the lower rack, while it's preheating.
The test for doneness is to take the loaf out and tap the bottom. It should sound hollow.
The nice thing about pizza dough is it's so flat that there's no danger of it collapsing, so you can get away with a wetter dough. Otherwise it's just like regular bread. I put some olive oil and dry oregano in the mix, and shape it and raise it in the pizza pan I'm going to cook it in. When it's ready, I pre-bake it for about five minutes, then add the toppings and bake it the rest of the way.
Make a large batch of bread dough (as above, wet dough is OK), and then instead of shaping it into a loaf, roll it out in a big square, maybe 8 inches by 24 inches (20x60 cm). A great trick is to use cinnamon instead of flour to roll it out. Then spread sweetener, nuts, raisins, whatever, making sure to go all the way to the edges, and roll it up from short edge to short edge, so you get a short thick cylinder. Cut it into about six pieces, and arrange them in a pan with high edges and just a little extra room, so when they rise they will fill the pan. Rise and bake.
You can also form bread dough into round flat shapes and fry them! So if you're squatting, camping, or living in your car, and you have a stove but no oven, you can still have homemade bread.
An extensive Sourdough FAQ
Naturally Leavened Sourdough Bread
and Naturally Leavened Bread
cover the health benefits of sourdough over commercially yeasted bread.
Against the Grain
is about all the ways that wheat has been corrupted in the industrial age, and how it can be made more healthful through sprouting or souring.
A page on the advantages of fresh stone-ground flour
, with a small section on sourdough.
(last updated August 2020)