Now maybe some of you think you've made sourdough. "How hard is that?" you are thinking. "You just mix the packet with a little water, throw in some yeast, and bake it up. What's he going on about?" I'm not talking about that kind of sourdough. I mean first-principles, grow-your-own-starter-from-scratch, prairie style sourdough. The point was not so much to produce the bread, as to explore the process by which you can actually make good bread with nothing but flour, water, and time.2
A few of you may still be with me. If you've ever tried to grow your own starter, you have probably gone through much the same process, and it ain't easy.
The article that started me off was John Ross's Sourdough Baking: The Basics. I've read a lot more sourdough stuff since then, but that article pretty much covers it and has provided the most consistently accurate information I've been able to find anywhere. There's a lot of misinformation out there, so don't believe anything you haven't actually tried. Ross makes the starter process seem a little easier than it actually turns out to be, but otherwise, the instructions he gives are spot-on.
Sourdough is bread made without processed yeast. It's not without yeast, as there is yeast aplenty. But the yeast doesn't come from a jar or a cake or a packet. You grow your own yeast by mixing flour and water, and letting it sit around on a counter for a while. There's yeast in flour already, there just isn't much of it. So you have to provide an environment that's friendly to yeast growth, and you have to feed it to encourage the yeasties to multiply and thrive. Luckily yeast eats flour, so all you have to do to feed it is add more flour and water.
The other thing that grows in a sourdough starter is lactobacillus. The bacteria (which are similar to the bacteria that make yogurt and cheese) form a symbiotic relationship with the yeast, eating yeast digestion products, and making the batter very acidic, which kills all the other microorganisms that are floating around in the air and water and everything else. Yeast (at least the kinds you want) can live fine in this acid environment, but nothing much else can, so the bacteria act as a preservative for your starter. The acid produced by these bacteria are also what gives sourdough bread its distinctive yummy taste.
Growing the Starter
I began my starter with whole-grain flour, since that's reported to have more wild yeast mixed in with it than the more heavily processed white flour. Actually, most sourdough resources say that rye flour is best of all, since it has a lot of yeast, and also has a lot of the glucose that the yeast like to eat readily available. But you can get a starter going with any kind of flour at all.
The way you make a starter is to mix some flour and some water into a sticky paste. The proportions aren't too important -- you should aim for a ratio of around 1 to 1 flour to water by weight, or roughly 3 parts flour to 2 parts water if you're measuring by volume. The water has to be below 120 degrees (this and all temperatures in Fahrenheit). Higher than that will kill the yeast. Heat is basically the only thing that kills yeast, so a little cold is better than a little warm. Eighty degrees seems to be ideal, so the water should feel about the same temperature as your skin.
Mix the flour and water, put it in something with a lid that can allow pressure to vent (a Bell canning jar with a loosened top is ideal, the wide-mouthed kind is even more ideal since it's easier to clean) and plop it on your counter.
Now wait. A long time.
Feeding the Starter
What's going to happen is, the wild yeast that's already lurking dormant in your flour will wake up in this warm friendly water bath, and discover that it's surrounded by glorious food. It will immediately start to eat the flour, excrete yeast's traditional digestion products, alcohol and carbon dioxide, and make lots of babies.
After a while, the yeast will have eaten up all (or most) of the flour you started with. It will run out of food, and billions of yeasts will die. Buddhists halfway across the world will wince at the death cries of your yeast. You don't want that to happen. So you've got to feed it.
Feeding a starter just means you dump out half of it, replace that half with a fresh mixture of flour and water, and stir thoroughly. This gives your yeasts fresh food to eat, and prevents the horror of a yeast famine. You should do this at least every twenty four hours. At the start, it won't look like anything's happening. Feed it anyway. After a few days, you'll start to see bubbles in your starter, and it'll have a smell to it. Not a bad smell exactly -- mine smells kind of fruity and alcoholic. If it smells downright bad, then something might have gone wrong. But it probably won't.
Starter Lessons I Learned the Hard Way
Eventually, when you've got a good strong starter, you can store it in the fridge and feed it weekly. But don't rush to this point. I refrigerated mine way too soon, and had to de-refrigerate it and put more time into getting it growing properly.
In my opinion, you should leave your starter out at room temperature and feed it daily for at least a month, and probably much more. This will give it plenty of time to gain the rising power that you need from it, and will give you time to get to know your starter, and learn how long it takes to activate, and how long it will stay active for. These things are very important when the time comes to bake with it. So leave that fridge alone for a while.
Another key point that I didn't see emphasized enough elsewhere is that your starter will need to be able to at least double its own volume. This should be obvious, since it has to be powerful enough to make your bread rise. But it didn't occur to me for quite a while. So a few bubbles and a sour smell is not enough! That's a good beginning, but you've still got a long way to go. I found that the scientific approach worked well. I'd feed the starter, then mark on the side of the jar where it was when I had just fed it. Every hour or so thereafter, I would mark again at the level the contents of the jar had reached. This gives you a nice time-lapse view of how active your starter is, and when it's slow or fast.
My starter, for example, sits pretty still for an hour after feeding. Then it starts to lift, gaining a little in the second hour, a lot in the third hour, and a lot in the fourth hour. At about hour five, it slows down, and just maintains for a couple more hours. Altogether, it increases in volume about 150% by hour five. At about eight hours, it has exhausted the food supply, and starts to fall. This information lets me get a good idea how long I'll have to let the bread dough rise for it to be fully risen (which is about four or five hours, and no more than eight).
And a final starter lesson: I began with whole wheat flour, as mentioned above. For a while, I continued to feed it wheat flour. This led to abject bread failure number one (see below) and a starter that clearly had some life going on, but wasn't really jumping out of the jar. Eventually, I transitioned over to feeding it white flour, and this made a huge difference. While they may have come from wheat flour, my starter yeasties really like to eat white flour. Perhaps the finer milling makes more of the food available faster? I don't know, but I would recommend transitioning any starter to white flour feed after a week or so. Mixing flour types in your starter won't harm it. It's all just glucose to the yeast.
Attempts one and two to make actual bread from my starter were abject failures. I learned something from each though. Mainly, I learned that my starter wasn't ready yet, but that's not all.
Attempt number one was made far too early. My starter didn't have nearly the CO2 production power it needed to actually rise a dough. I ended up with a rock-hard lump of petrified flour. But I also learned that the traditional form of a sourdough loaf (a dome shape, basically) requires a pretty stiff dough to hold its shape for the long rising process. If you're accustomed to making yeast bread in a loaf pan, you'll want your dough to be a lot firmer than you're used to making. Of course, you can make sourdough in any shape you like. But I wanted the dome loaf, so that's something to note.
Attempt number two was made later on, when my starter had more power, but still not enough. I tried to make rolls, thinking the smaller pieces of dough would have an easier time rising, but no dice. Here too, I re-learned the stiff dough lesson. The rising process of sourdough also tends to make the dough progressively more wet, as gluten is consumed and alcohol excreted, so a very stiff dough will soften over time. If it starts out exactly as wet as you want it to finish up, it will end up far too soft, and will collapse. This is a totally unfamiliar experience in commercial-yeast baking, and very important to note.
Success at last!
After failures one and two, I decided to concentrate on the starter. So for a good month, I left it on the counter, fed it every day, and watched it pretty carefully. This was also the period when I transitioned to feeding it white flour.
A few days ago I gave it a feed in the mid afternoon. It rose pretty well, approximately doubling its volume. Before I went to bed that night, I didn't feed it again but I gave it a thorough stir. The next morning I looked at the jar and realized that my stir had prompted unknown heights of expansion. The high-tide line on the inside of the glass, where the starter had risen to before it fell back again, was almost three times the original level of the starter. This was something I hadn't ever seen.
I went through a few more feeding cycles to get a sense of how long everything took. I identified the timeline described earlier, and found that it was very consistent across feedings. Finally, it was ready.
My bread recipe was a slightly modified version of Ross's basic recipe in the article that started it all. It went as follows:
That's all there is to the dough. When I had a good elastic dough, I stretched and rolled it into a ball with a good tight skin on the outside, and placed it on the pan I intended to bake it on. I put a large glass bowl upside down over it, to keep the moisture in without actually touching the dough. I then put this whole thing in the oven, which was warmed slightly by its pilot light. You should be able to rise it wherever you normally rise bread.
- Add a cup of water and a cup of flour to the starter and let it go through about three-quarters of a cycle. This should be the point when the yeast is most awake and active.
- Mix two cups of the proofed starter (called "sponge") from step one with 2 tablespoons of olive oil, and 4 teaspoons of sugar.
- Add flour one half cup at a time, until the dough just holds together.
- Add 2 teaspoons of salt. You don't want to do this too early, because salt is bad for yeast, but you need salt in there for the bread to rise properly, so do it about halfway through adding flour.
- Add more flour until you have a stiff bread dough. Ross calls for three cups of flour. I found that after two cups, I had a dough so dry I had to put in a little more sponge to moisten it. So the amount of flour all depends on how wet your starter is (which will vary a lot) and what kind of flour you're using. This just has to be done by feel.
- Now knead for at least fifteen minutes. Like any bread, you need to develop the gluten to make little elastic pockets for the yeast to fill with CO2.
After you make the dough, make sure you've got some extra sponge left. Give this a feed and put it back in your jar, because it's your starter for next time.
Then you wait, much longer than you'd wait for processed-yeast dough. My bread took about four hours to rise all the way. You can tell if it's risen by poking it gently. When it's still rising, it will feel very tight, and the dent you make will spring right back from the gas pressure inside. When it's done rising your finger dent will stay poked-in.
When the rise is done, slit the top with a sharp serrated knife dipped in cold water, and bake! Ross calls for starting in a cold oven which you let heat up to 350 degrees with the bread in it. I simply popped it in a 500 degree oven, but honestly I'm not that happy with how the crust came out, so I might try his suggestion next time. You are free to choose your own baking method.
When it's golden brown and sounds hollow when thumped, it's done. Let it cool completely before you cut it. Then slice and enjoy some of the best goddamn toast you will ever have.
Only the Beginning
This article just touches on the bare bones of sourdough. You can make any kind of bread as a sourdough, you can use the stuff for rolls, pizza dough, or any other bread product you can imagine. There's a whole bunch of sites with much more info about sourdough out there. One of the best I've found is Sourdough Home, which is a little hard to navigate but has a lot of useful info. Caveat lector though, as I've found many sites perpetuating untrue sourdough myths and giving some really dumb advice.
The above is also by far not the easiest way to obtain good sourdough bread. In fact, it's probably the hardest way. Easier ways include going to your local grocery store or bakery and buying some, purchasing or getting a proven starter from a friend, or buying a sourdough mix. But if you're interested in the process of baking as much as the results, stubborn enough to want to make something that is wholly yours, and perhaps have a bit of a scientific turn of mind, you might find sourdough baking a fun and satisfying hobby.
1 Not really.
2 Technically, the actual bread as baked also contains salt, oil, and a little sugar, but those things are not necessary, merely desirable.