Category Archives: culture this

Sourdough Diaries: The Beginning—Introducing Ezekiel and How and Why to Make a Sourdough Starter

This is Ezekiel:

a grainy, cameraphone picture that would totally be his f'book profile pic if i ever got crazy enough to make him one

In some ways, naming your starter seems completely natural—it bubbles and teems with life, eats and excretes, requires maintenance, and, if neglected, will die. It’s a little like a very quiet, low-maintenance pet. I named the other two starters I cultivated, too: Isaiah, who I converted from an Amish friendship bread starter which probably initially included sugar and milk to a far more Spartan diet of whole wheat flour and water and then killed because I suspected the friendship starter relied on active dry yeast and I wanted a “wild” starter (I’ll explain the scare quotes in a minute) and Esther, who I stopped baking with and eventually let suffocate and die in her own excrement.

It’s not just me. I also know of a Lisette, a Philemon, and a Mr. Googly (gluten free). And Amish friendship bread starters, which are a kind of sourdough starter, were so often called  “Herman starters” or simply “Hermans” that there are still dozens of recipes out there that call for “1/2 cup Herman.” I really tried to figure out why and for a minute, this wiki page made me think it was something German passed down through the Pennsylvania Dutch that just happened to be a common name…until I noticed that even “Herman-Teig” has only been well known since the “1980er.” Which is about when most people’s fond memories of their mothers or aunts caring for and baking with “Hermans” date from (likely influenced by the 1970s Earth Mother vogue and what Warren Belasco has called the “countercuisine”). Also challenging the Pennsylvania Dutch theory: the English-language wiki claims that Elizabeth Coblentz, author of “The Amish Cook” said the rich cinnamon coffeecake that people sometimes flavor with instant pudding mix was nothing like Old Amish “friendship bread.” So while I’m skeptical, I have nothing to definitively dispute stories like this one from Uncle Phaedrus, Finder of Lost Recipes:

"Herman is a name that was given to a sourdough starter many years ago when a young girl (probably in San Francisco) watched her mother making sourdough. The mother explained that the sponge was a living thing and needed to be feed and watered. The little girl, in the way of little girls everywhere and everywhen, decided that it needed a name like everything else that was alive, and some things that weren’t. After due consideration, she bestowed the name "Herman" upon it.

Like most good things the mother wanted to share the starter with her friends. Along with the starter went the anecdote of her daughter’s naming the sponge. As friends gave this starter to other people, they also received the story of the little girl. To this day "Hermans" seem to pop up among sourdough aficionados everywhere, all due to a little girl and her need for everything to have a name. "


But the sad stories of Isaiah and Esther start to suggest some of the ways the “pet” analogy breaks down: it’s a pet that you routinely kill and eat every week or so, but that nonetheless can live for centuries in the right conditions—something between Rose Nyland’s pet cow and octogenarian Penn State football coach Joe Paterno. There are websites that will sell you starters that supposedly have special historical/regional pedigrees, and even one with information on how to get a starter that was carried west on the Oregon Trail in 1847 for free (in memory of Carl T. Griffith who, as the site claims, “gave a sourdough starter to anyone who asked, or who sent him a self-addressed stamped envelope.”) [A minor aside to the two people who’ve landed on this site in a google search for “oldest verified sourdough starter,” if you didn’t leave in a huff at my blog’s irrelevance never to return: I’m sorry to say I have no idea.]

Furthermore, I’m not totally sure what I’m referring to when I talk about “Ezekiel.” Is he (or should that be “it” or “they”? Is it totally perverse to assign my starter a linguistic gender?) just the particular strain(s) of yeast I’ve cultivated or is/are he/it/they the fermenting flour and water paste? The problem with the former is that I can change the kind of yeast living in the culture by changing how I feed him/it/them or what temperature I store (oh hell with it, if it’s perverse, it’s perverse:) him at. The problem with the latter is that I add about 1 1/2 cups of fresh flour and water every week, and remove about the same amount. I could convert him almost entirely to a new kind of flour in about a week’s time, in which case almost none of the original Ezekiel would be left. The compulsion to assign your starter a unique name seems, instead, like a symptom of the being-a-foodie-makes-me-special nature of most contemporary sourdoughing. No offense meant—I’m clearly guilty of it, too.mid-refresh

Anyhow, I won’t deny that I’m fond of Ezekiel, and maybe sometimes even a little stupidly proud in what only a non-parent could call a “maternal” way: My yeast culture! He’s 19 months old! And already he’s leavened everything from naan to chocolate cake! So, below the jump, instructions for one way to make your own little mason jar full of joy and fermented flour paste…oh, and an explanation about what a sourdough starter is in the first place.

dry and cake yeast, from the excellent Cooking for Engineers: at its most broadly defined is some combination of powdered grains or legumes and moisture, usually water, heated (Harold McGee offers a much better explanation of what actually happens to the proteins and starch and gas cells in the dough if you’re into that sort of thing). There are two basic kinds of bread: unleavened and leavened, a distinction relevant mostly to observant Jews who don’t eat leavened, or risen, bread during Passover (“the festival of unleavened bread”) to commemorate the exodus of Israelites from slavery in Egypt, when supposedly they had to leave so quickly, they didn’t have time to let their bread rise. There are multiple ways of leavening bread, including mechanical leaveners, like egg whites that have air literally beaten into them, chemical leaveners like baking soda and baking powder, and yeast.

from When using yeast to leaven bread, most contemporary bakers use active dry yeast or yeast cake purchased separately from the other ingredients in the bread. However, yeast exists…everywhere. It’s in the air, it’s in the soil, and it’s definitely present in, around, and on everything that ferments. The white bloom on grapes: yeast. The specific restrictions on what counts as “leavened” bread for observant Jews are actually relevant to the explanation of what sourdough is and how you make it: in order to be kosher for passover, bread made from wheat, barley, spelt, rye and/or oat flour must be baked within 18 minutes of being moistened with water. The reason for that is that there is yeast in grain flours, and once moistened, it will start to eat the starches in the wheat and produce gas—leavening the dough.

Some people will claim that the yeast in sourdough starters made without commercial yeast is coming from the air—and while that’s theoretically possible, it’s sort of unlikely. That’s why sourdough doesn’t rely on “wild” yeast. Yeast were probably one of the first domesticated organisms. For humans relying on agriculture for food—so basically everyone since people settled in cities, the literal dawn of civilization—fermentation made long-term food storage possible and made many nutrients more available. So yeasts likely developed in symbiotic fashion along with many agricultural products like grapes and wheat.

But there’s not enough yeast in most flour or in the air to leaven bread much, at least not before other kinds of bacteria and mold begin to grow. So that’s where the sourdough starter comes in handy—it’s a yeast culture developed specifically for the kind of flour you use and the specific conditions of the kitchen where you bake. And once you get that much yeast going in a flour-water paste, they produce a lot of byproducts like ethanol and lactic acid, which prevent other things from growing.

There are lots of reasons besides foodie cred or lack of access to active dry yeast why you might want a sourdough starter—1) it’s cheaper, because yeast is basically the most expensive part, per weight, of bread baking (unless for some reason you’re baking with saffron or vanilla beans), 2) the byproducts are flavorful, so while you have to let it rise a long time to get something that will taste like a real sourdough, you’ll still get more-bready breads with a sourdough starter compared to packaged yeast, 3) it may be healthier? There have been at least a few studies suggesting that fermentation makes the nutrients in flours more available and moderates the effect carbohydrates have on your blood sugar—I’ll look into this more some other time, this entry has already gotten a little out of hand and I haven’t even started explaining the process yet and 4) it will compel you to bake weekly or at least semi-weekly, which I know has improved my quality of life.

Also, it’s really easy, or at least it was for me (a friend in Australia has had some issues, and I wonder if there are some more aggressive molds there…). Anyhow, theoretically, all you have to do is combine some flour and water and then let it ferment. It usually takes somewhere between three days and a week to be strong enough to leaven bread, which might happen naturally if you just leave it alone, but most methods I read about before I created Ezekiel suggested that you feed your proto-starter approximately every twenty-four hours. That said, my starters all seem to “die” after a couple of days, and I’ve only gotten them to dough-leavening strength by leaving them alone for a little while. So the whole process, which I learned here, goes something like this:

Day 1: Combine 1 cup flour and 1 cup water in a plastic or glass container and cover loosely (cloth or plastic wrap with 2-3 holes punched in it)

Day 2: Stir well, discard* half of the mixture, add ½ cup flour and ½ cup water, stir and cover

Day 3: Stir well, discard half of the mixture, add ½ cup flour and ½ cup water, stir and cover

Days 4-10: If it’s beginning to bubble and smell yeasty, continue the routine for days 2 & 3 until it will rise a small amount of test dough.

If it isn’t bubbling and instead just separating into liquid and paste, stop feeding it and just leave it alone for 3-4 days; eventually, you should begin to see bubbles forming in the bottom of the paste mixture. At that point, without stirring it, pour off all but ~1/4 cup—you want to get rid of the liquid on top which will probably be greyish or brown, and the paste closest to it, but keep a few tablespoons of the clean, bubbly stuff at the bottom. Then, add 1 cup flour and 1 cup water, stir and cover. Then return to the routine for days 2-4 until it reliably gets frothy after feedings and will rise a small amount of test dough.

*I’ll post recipes for the “discard” in another entry.

What to look for:shortly after refreshing, getting all bubbly

A starter that’s ready to bake with will become frothy on top after feeding, sometimes bubbling instantly and definitely within 8 hrs. It will stay frothy until about 18 hrs after a feeding, when the bubbles may subside as it separates into a thick layer of flour-water paste underneath a layer of clear or yellowish liquid (a combination of water, ethanol, and lactic acid called hooch).

To test a starter for rising power, combine 1 tsp. starter with 2 T. flour, a pinch of sugar, and enough water to make a little ball of dough. Cover that and let it sit—you can put it on parchment or wax paper and mark its dimensions if you’re not sure you’ll be able to tell whether or not it has grown. Within 4-8 hrs, your little ball should double in size. If it can do that, it’s ready to make bread.


Starters are resilient—the yeast tend to beat out other competitors because most bacteria aren’t very good at digesting starches and the acid and alcohol create an inhospitable environment. However, if your starter ever grows pink, purple, or dark brown things, throw it out and start over (the smell will also turn from pleasantly yeasty and beerish to rancid and foul).

If you leave it too long between feedings and aren’t sure if it’s alive, try pouring most of it out, leaving just a few tablespoons and feeding it with a whole new batch of flour and water (1 cup each).

at home in the refrigerator


If you keep it at room temperature, you’ll have to feed it almost every day, so I choose to keep it in the refrigerator. You can even freeze a starter for up to 3 months, or pour it onto parchment paper, let it air dry, and then crumble it into powder, which is a good method if you want to mail starter to someone, or if you’re moving and won’t have reliable refrigeration for a while. Once thawed or reconstituted in some water, a frozen/dried starter should work just like it did before.

Refreshing and maintaining:measuring out refreshed starter for baking

Basically all sourdough recipes call for “refreshed” starter, which means the yeast are good and active—to refresh, I usually pour my starter into a glass bowl, add 1 cup water and 1 cup flour, cover it with plastic wrap and let it sit overnight or for 6-8 hrs. When I’m ready to make the dough, I measure out as much starter as I need into a liquid measuring cup, add ½ cup water and ½ cup flour to what remains in the bowl, mix well, and then pour it all back into the quart-size canning jar I store the “mother” in (which I cover with plastic wrap secured with the canning jar ring, poke 2-3 holes in the plastic, and return to the refrigerator). For me, it works best if I’m using 2 cups of starter to bake with, because I’m basically adding 1 ½ cups water and 1 ½ cups flour to the starter every week, which creates about 2 new cups of starter

The more often you use it/feed it, the quicker your rising time will be. If you don’t feed it at least once every 2-3 weeks, it may produce too much ethanol or lactic acid and/or start to run out of food, and get sluggish or die. If you don’t have time to bake, you can just stir it well, pour half of it off, and feed it with ½ cup flour and ½ cup water to keep it going in the meanwhile. Again, I’ll post recipes soon for what to do with the “discard” if you don’t want to throw it out.

If I need ½ cup or less for something, instead of refreshing the whole jar, I’ll usually just stir the starter well and measure out half as much starter as I need. Then I feed both the jar and the small portion I’ve poured out—e.g. if I need 1/2 cup starter, I’ll take the jar out of the refrigerator and and mix it well, and then measure ¼ cup into a bowl. I’ll add ¼ c. flour and ¼ c. water to the jar, mix well, and return it to the refrigerator. Then, I’ll add ¼ c. flour and ¼ cup water to the starter in the bowl (to refresh it), cover it with plastic wrap and let it sit at room temperature for 6-8 hrs. There will be a little extra, but I’ll either put that in the dough anyway or just throw it out, or make a tiny griddle cake with the leftover.

Using starter in other recipes:

These instructions produce a 100% hydration starter—meaning it has equal parts flour and water. A 50% hydration starter would have twice as much flour as water, and be more like a dough than a batter. Most recipes I’ve come across call for 100% hydration starters, but if you’re handy with a calculator you can adjust the flour/water ratios in recipes for other % hydration starters as necessary.

To substitute for 1 package of yeast, you need to use about 1 cup of 100% hydration starter. 1 cup of starter = ¾ cup flour and ¾ cup liquid. So, for a typical 1 or 2 loaf yeast bread recipe, you would use 1 cup of starter and subtract ¾ cup flour and ¾ cup liquid. Unless your starter is very active, you should also assume it will take about twice as long as packaged yeast to rise. For chemically-leavened breads (quick breads like muffins, biscuits, sweet breads, cookies, etc.), you can use 1 cup of your starter to replace ¾ cup flour and ¾ cup liquid.

Choosing flour:

Use whatever flour you want to bake with. As far as I know, any kind will work, but wheat and rye are by far the most common. Starters will develop the kind of yeast that works best for the flour they’re fed and the temperature of your kitchen. However, you can convert any starter to another kind of flour by feeding it with the new kind of flour for about a week. Also, a starter made with any kind of flour can be used to raise bread made with other kinds of flour. I feed my starter with high-gluten white flour (regular “bread flour”) but often add whole wheat flour for flavor and fiber. You can always use rye, whole wheat, spelt, corn, oat, garbanzo or other flours for part or all of the flour in most bread recipes. Low or gluten-free flours may not perform as well for some breads—especially ones that rely on gluten for their light, airy textures (crusty boules, baguette, ciabatta).

Home-cultivated Yogurt: Part 1 in the “Culture This” Series

teeming with my little pets

If yeast strains had feelings, which are really easy to project onto them once you start giving them names, I suspect my 15-month-old sourdough starter "Ezekiel" would be seriously cheesed about losing out on the first "culture this" series to yogurt. But turning milk into yogurt is (very marginally) easier than turning flour and water into a starter, and life is busy in the fall when you work in education and watch an absurd amount of college football every weekend. Lame excuses, I know.

Why culture?

Lots of people will claim that home-cultured things taste better or are healthier for you, but those are either entirely subjective or up for serious debate. The main reasons I like culturing things are

  1. It’s cheaper. Milk is cheaper than yogurt, so even though you have to start with a little bit of yogurt the first time, even your first batch will cost less than it would to buy the same amount of yogurt someone else cultured. And it’s not like that’s a complicated or labor-intensive process. As Harold McGee noted in his recent NYTimes article on yogurt, the bacteria are doing all the work here. Why pay someone else premium for something that takes no effort or skill to do yourself?
  2. It gives you more control over the process, which is part of why people often end up thinking it tastes better. You get to decide how tart, how thick, how rich, and how voluminous you want your yogurt to be. You can start with soy milk if you prefer soy yogurt or skim milk if you want it to be fat-free. You can strain it if you want something closer to Greek-style yogurt at a tiny fraction of the cost. You are the master of your yogurt kingdom.
  3. It’s like having a science experiment/pet in your kitchen. With both yeast and yogurt cultures, you’re basically cyclically growing more by feeding them and putting them in a hospitable environment. They multiply like crazy, and when you have enough of them to suit your purposes, you crush their little yeasty or bacterial dreams of total world domination by putting them  back in a less hospitable environment. There’s a nurturing appeal, too, which probably seems to conflict with the idea of thwarting their imagined imperial ambitions, but it’s true: I like the sense of ritual and continuity. For yogurt, I like saving the last few tablespoons of every batch for the next one, swaddling the container in towels to keep it warm, and knowing when I eat it that it’s something I fed and grew

Sold? If so, I welcome you to "culture this" part 1:

How to make some milk and a little bit of yogurt into a lot of yogurt

I know it doesn’t sound super impressive when I put it that way, but it’s not super impressive once you’ve done it. If you’re looking to impress, you can call it "Homemade Yogurt" and not really be lying, but this not like a "wild" sourdough starter* where you’re cultivating yeasts in the flour or in the air that will thrive in precisely the conditions you set up in your personal kitchen. If that kind of sourdough is growing from seed, or raising volunteer plants, yogurt is planting a seedling you picked up at the local nursery. Basically every recipe I’ve seen for "homemade yogurt" involves a starter culture. This is also probably why I haven’t named mine—I sort of feel like its proper name is "Mountain High Yogurt," because that’s the brand I started with.

The whole process goes like this: you heat some milk until it steams, you let it cool back down until it’s warm but you can put your finger in it without too much discomfort, you stir in a few tablespoons of yogurt, and then you let it sit for 4-24 hours.

The specifics: eh, that looks like about how much yogurt I want

Step 1: Heat approximately the volume of milk you wish to culture to 180F

I use a ceramic crock I picked up for $2 at a re-use store, and generally just measure out the amount of milk I want by filling the crock up most of the way and then pouring that into a pan. Not super scientific, I know. If you want to make a specific amount of yogurt, measure out that much milk less 1 oz per cup for the yogurt you’ll stir in as a starter. If you’re planning on straining it, use approximately twice as much milk as you want to end up with in yogurt. 

Step 2: Let it cool to 110-120F (takes about 30 min for me, will vary based on the volume and vessel)featuring the waterproof thermometer I got after destroying three non-waterproof ones in about a year

Don’t skip this step, or you’ll kill all the bacteria. I did that the second time I tried this because I thought I remembered how to do it and didn’t need to look it up again and ended up throwing it out, although I probably could have just added more yogurt, but I didn’t have any at the time and this is all sort of contrary to the whole economical argument but the point is, don’t forget to let the milk cool back down. Just like yeast, temperatures over 120F will kill it. Apparently the reason for heating it to 180F  rather than just taking it up to 120F in the first place is that the higher heat changes the whey proteins and, McGee says, "helps create a finer, denser consistency."


Step 3: Whisk in approximately 1 oz. yogurt for every cup of milk you’re using

You can use any kind of yogurt with active cultures, and like McGee, I’ve found that the cheaper the yogurt I start with, the better my own stuff turns out. The more expensive unsweetened, organic, or Greek-style yogurts often only have one or two kinds of bacteria in them whereas the cheap stuff generally has a lot more and they’re apparently super active. Sure, those brands also tend to have sweeteners and additives, but all of that will get diluted so much in your end product that they won’t affect the taste much, if at all. Certainly not by batch #2.

McGee recommends 2 T. per quart, but I tend to use a little bit more. The amount of starter culture and length of time you let it sit are what will determine the tartness and consistency, so you can play around with both to figure out your own "perfect" yogurt.

Step 4: Put in an insulated airtight container and seal

This is where the crock with the airtight seal comes in handy, but I imagine plastic wrap and a rubber band would do just as well. Whatever your vessel, you’ll want to wrap it in a few towels. I secure mine with mega rubber bands like so: the kitchen towels du jour involve men in toques and a towel I suspect was "borrowed" from a gym at some point

Step 5: Taste every 4-hrs or so to see how it’s coming along

Try not to stir it, as you want to keep the milk still until it sets, but you can take just a little off the top to see how tart and creamy it is. McGee says four hours will do it, but I’ve had better luck letting it sit 12 or more hours, usually overnight. Earlier than that and I’ve gotten really mild, milky results.

What’s happening as it sits is that lactic acid produced by the bacteria causes the protein and fat in the milk to form a continuous network, which the water gets suspended in (well, except for the part that leaks out or pools on the top, which is whey). Those networks are what make yogurt thick and creamy.

Skim and soy milks will never set up as thick as whole milk, which is what I generally use. Commercial manufacturers often add gelatin or starch, which I imagine you could do at home. Using starch, I would probably start by making a paste of 1-2 T. corn starch or arrowroot powder and an equal amount of milk, and then I’d whisk that into the rest of the milk before heating. Using gelatin, I’d just sprinkle a package or two over the cold milk before heating and let it sit or "bloom" for 5-10 min and then heat as usual, stirring constantly and making sure the gelatin dissolves. I can’t say for sure that would turn out great, but if you’re a soy or non-fat yogurt eater and you want to try making your own at home for cheaper, it might be worth a try.

Step 6: Refrigerate and enjoy

The yogurt will continue to set once in cold storage and the lactic acid production will slow to a halt. Kept cold, it should last for weeks—the acid helps preserve it much longer than fresh milk.

I love it for breakfast sweetened with Grade B maple syrup (which is cheaper, more flavorful, and more nutrient-dense than Grade A) and topped with fruit and granola. I also love it salted and mixed with vegetables and/or herbs as a sauce with fish. And strained, sweetened, and frozen it makes a great dessert.

Optional Step 7: Strain

If you want a thicker, Greek-style yogurt, pour it into a cheesecloth-lined colander or a fine mesh strainer and suspend over a bowl for several hours. The yellowish liquid that drains out is whey, which contains protein and a number of vitamins and minerals. Some athletes drink whey, often sweetened or salted, as a workout-recovery drink (whey powder is also part of many supplements). If you’re not into drinking it straight, you can also use it as some or all of the liquid in most baking recipes. Processed foods sometimes contain whey, so I’m sure food product developers could tell you what difference it makes but so far, I haven’t been able to tell.

*Scare quotes for "wild" because I’ve been convinced by Aaron Bobrow-Strain that even sourdough starters cultivated without the use of packaged yeast or a pre-made starter aren’t really "wild." Much like corn and dogs and modern chickens, yeast and human civilization co-evolved, so even seemingly "wild" strains of s. cerevisiae yeast are the product of agriculture and human-yeast interaction. That said, there ought to be a way of distinguishing between starters that rely on booster yeast or heirloom yeasts and the ones that you grow in your own kitchen to fit your personal rhythms of baking. Apparently Bobrow-Strain has been working on something for publication about baking and yeast ecology with Melanie DuPuis so I’ll try to keep an eye out and post the reference for anyone interested in that sort of thing.