WHAT IS SOURDOUGH STARTER made of? I’m interested in growing all manner of things, so one photo in a new cookbook on sourdough baking that showed a glass jar of bubbling-over starter caught my attention. It’s alive, I thought–full of multiplying microbes that do good work in behalf of the baker, and also for those who then eat the goods baked with it.
Those of you who are regular listeners know I have a similar fascination with other forms of fermentation and culturing–making homemade yogurt, or lacto-fermented concoctions from fruits and garden vegetables, for instance.
Along those lines today we’re going to learn about sourdough, and specifically about how to grow your own homemade sourdough starter from a few humble ingredients.
No, no mail-order packets of the stuff are used by Sarah Owens, author of “Sourdough: Rustic Recipes for Fermented Breads, Sweets, Savories, and More.” Originally a professional ceramic artist, Sarah trained as a horticulturist at New York Botanical Garden’s School of Professional Horticulture.
After graduation in 2009, she spent the next six years specializing in the organic care of roses at Brooklyn Botanic Garden, as the BBG rosarian. In 2013, Sarah founded BK17 Bakery as a way to bring real bread back to Brooklyn.
Sarah visited my public-radio show and podcast to talk sourdough 101.Read along as you listen to the Feb. 22, 2106 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
my sourdough q&a with sarah owens
Q. You came to sourdough baking because of your own food intolerances, I read in your bio in the book—but I didn’t know that, because the book doesn’t look like it’s for anyone who’s skipping anything. It’s all so fabulous looking.
A. Thank you. It’s true; I definitely at one time had some major intolerances to a lot of different things, and a lot of different grains besides just wheat. The lacto-fermentation of sourdough really helps to mitigate those intolerances, as well as some other lifestyle changes I had to make at the time.
Q. In the same way I think for some people who can’t digest dairy so well, sometimes yogurt that’s been cultured for a long, slow period can be digestible. It’s interesting.
A. Exactly. The big difference between something like sourdough and the yogurt is that the wonderful microbes do all the work for us before we bake the bread, and sort of make it more digestible for us. It’s almost like thinking of the culture or starter as an extra stomach. [Laughter.]
Q. The pre-digester.
It’s very obvious in this new book that you are a gardener—not just a baker—and I would say from the photographs that it’s obvious that you have a background in ceramics, too. I can see your three-dimensional design sense, too.
But you can tell you’re a gardener from many things—some of the ingredients you choose to incorporate into your recipes, but also there’s even a page about making compost tea. Tell us how that connects to sourdough—because obviously we’re not putting it in our bread.
A. Oh gosh, I hope not. If anybody does, let me know. That would be fascinating. [Laughter.]
Q. But it’s all about the food web.
A. Correct. It’s really important to remember that a sourdough culture is something that’s alive, and we’re sort of nurturing these different microbes. The bacteria and other little critters are running around in our culture of flour and water. We’re nurturing thee things in order to be able to produce something beautiful and tasty. In the world of gardening, we have to remember that we aren’t just growing plants, but we’re nurturing a microbiome in the soil that allows us to grow really beautiful, wonderful, tasty plants. So the concepts are very similar.
Q. Your appreciation for that almost-invisible end of the food chain really comes through. Speaking of recipes for cultivating that near-invisible end of the food web: If we want to make sourdough starter, first what is it and what purpose does it serve?
A. Starter is really a very simple formula. It’s flour and water that is combined to create a medium for microbes to thrive. Those microbes are a combination of bacteria, Lactobacillus bacteria, but also different strains of wild yeasts. Those two things live together in symbiosis. The bacteria create a very acidic environment, where a lot of the bad guys or bacteria that spoil our food cannot thrive. But the yeast that we cultivate to leaven our bread can.
So it’s a really fascinating mix. Really by simply activating the starches in flour using water, and helping that process of converting them into sugars, allows the microbes to be able to feed. So they give off carbon dioxide—and that leavens our bread.
However, the bacteria also do this wonderful thing for us—the pre-digestion component, that you don’t get with something like commercial yeast.
So that’s what really differentiates sourdough in terms of the digestive component, but also in terms of the flavor component. Those lactic-acid bacteria put off these sorts of ethyl alcohols that are absolutely delicious.
Q. Interesting. So it starts there. I was interested to see that you make your own starter. People I know order packets of starter by mail, but you have what I think is a European-inspired, oldtime recipe that involves raisins and flour and so on, and I think you call it the Mother.
A. Yes, I call it the Mother because it gives birth to so many different recipes in the book.
There are so many different ways that you can approach creating a sourdough culture, but I found for myself way back when I first started creating and working with sourdough that it is much easier to create what is referred to as a yeast water first. That yeast water is composed of dried raisins, some honey, water, and some sugar. It creates a bubbling fermentation liquid that is then used to inoculate the flour and the water that we mix it up with.
Q. Shall we go through the steps? Dare we try to do that? [Laughter.] I have these simple ingredients, and some glass or ceramic jars, I assume…
A. Glass or ceramic is best; you have to remember that acidic cultures light eat away at anything that might be reactive, like copper or plastic.
Q. I have water, sugar, honey, raisins, flour…where does the process begin?
A. Depending on the season and the ambient temperature in your kitchen, that’s going to influence how long it takes to create the starter. So for a warmer kitchen, it may take five to seven days; for a colder kitchen it may take a bit longer. Those are some things to remember, especially in the beginning when you’re not used to dealing with a culture. You sort of stare at the mixture, like, “Is it actually going to work?” [Laughter.]
I always tell people to find a warm spot in your kitchen. For some people that can be the top of the refrigerator. Some people like to switch on the light in their oven , which creates some warmth, and store it there.
The key is to remember not to forget it. [Laughter.]
Q. There you go: Like much of life, Sarah, the key is to remember not to forget.
A. Yes, be mindful. So the first step is really to mix up or dissolve the honey and sugar in water, and combine that with the raisins. I like to put that in a container where you can allow some air exchange.
You have to remember that these microbes are living and breathing things, and need to be able to take in oxygen and give off carbon dioxide to thrive. Being able to either pop the lid and leave it loose, or remove the rubber gasket and lightly screw on the top—that kind of container is what you are looking for.
Q. No hermetically sealed containers. [Laughter.]
A. You’re going to give that a nice shake at least once a day, to incorporate more air into the mixture. Hopefully, if you’re lucky, after about three to four days—maybe five to six—you’ll see some air bubble rising to the surface, and that’s your first indication that you have signs of fermentation going on. That’s a really good thing.
You’ll smell the difference; you’ll smell a sort of alcoholic presence. It’s almost like making homemade hootch. [Laughter.] Although this is a really sweet hootch.
Once that gets bubbling, that’s when it’s ready to inoculate your flour and water. You use it first to mix with your flour, and let that sit overnight or about eight hours.
You should see after about eight hours some bubbles in your mixture. And then you have to feed it again. You have to remember that these microbes are hungry; they have to be tended to or fed to keep them happy.
Q. So interesting. I’ll give all the exact measurements [see the box at the bottom of the page, below this transcript], but people should understand that when we say flour, we’re not talking the flour, like X number of cups to make a loaf of bread, but we’re talking about the flour needed to make this starter.
A. Correct. Once you get your flour and hootch concoction going and bubbling [laughter], all you need to do to maintain it is give it equal amounts of water and more flour by weight of the starter.
So if you end up with 100 grams of starter mixture, then you always want to feed it with 100 grams of water and 100 grams of flour. That provides the culture enough food to feed and grow and stay active and happy.
Q. I always hear with bakers—and it doesn’t take long—but expert bakers always start talking in grams. And that makes me want to say we can’t think about cups. Many of us who cook at home, amateurish, don’t even know the difference between liquid and dry measure, let alone grams. But using a gram scale is a really great thing and they’re not expensive. It’s important.
A. It’s so wonderful. A lot of people think, “Oh, do I have to be that exact?” But it’s more than just the science of baking. It actually cuts down on the mess in the kitchen.
Q. It does. I’ve watched expert bakers who have their mixing bowl on top of their scale, and they’re just measuring right into that bowl, one ingredient after another.
A. You don’t have to clean as many dishes, and it makes life so much easier. It also for beginning bakers when you need a baseline to hone your skills, it takes a lot of the guesswork out of baking.
Everyone I’ve ever met doesn’t measure the same cup of flour; it’s always a little different. Especially when you’re working with flours other than commercially prepared ones, like stone-ground local flours, it really helps to take the guesswork out of the weight of a cup.
Q. I didn’t mean to interrupt—but now this thing is bubbling over and hungry, and you’ve been feeding it…and I think one starter you called Jabba the Hutt, which made me laugh.
A. [Laughter.] Depending what flour you use to feed your starter, they take on vastly different personality characteristics. I always tell people it’s really great if you can give your starter a name, because you will tend to be more attentive to it, and think of it as something you have to keep alive.
Q. You don’t leave it in the oven with the light on and forget about it for fours weeks.
A. [Laughter.] Oh gosh no, I hope not.
Q. So we have this bubbling, live thing and we’ve been feeding it and measuring carefully, and at what point is it ready to do service as a starter?
A. A wonderful test to see if it’s ready is to take a big, heaping spoonful and drop it into a glass of water. If that spoonful floats, you know that there is enough carbon dioxide trapped in the starter to be able to leaven your bread.
Q. Oh. Interesting.
A. It’s a really wonderful test. And it goes for a new starter as well as a starter you’ve maintained for awhile. I always tell people that it sounds like a lot of work, but once you get a starter going, you can keep it in the refrigerator and feed it a minimum of once a week. Then when you get ready to bake, you can pull it out, feed it a couple of times and get it going and then perform that test again to make sure it is ready to leaven your weekend loaf of bread that you want to bake.
Q. Is this a forever thing, or does eventually the starter wear out even with feeding and watering and TLC (and being named and patted on the head)? [Laughter.] Even with all that, does it finally go kaput?
A. People have maintained starter cultures for over 100 years. It’s really amazing. As long as you are consistently feeding it with flour and water, and keeping those microbial populations high, you should be able to maintain your starter infinitely.
You will notice that its behavior will change, considering the season and how hot or cold it is in your kitchen, and also the different types of flour you feed it.
If you feed it a stone-ground flour that’s been freshly milled, that flour is going to have a lot more available foods to the microbes in your starter, so it’s going to ferment a lot faster. It’s also going to have a very different smell. I always tell people to really engage all of your senses when maintaining a starter. The smell will change, not just appearance.
Q. So we have this forever friend that we feed and care for. I think you say in the book that you like to keep from 150 to 300 grams on hand at all times. Those of us who bake mess might only need half of that, but we need to keep refreshing and feeding it no matter the amount.
A. A lot of people are what I would call a weekend baker, and they only need to keep about 50 to 75 grams in a small jar in the refrigerator at any one time. That allows them to feed it or refresh it without having a lot of extra starter on hand.
If you do end up with a lot of extra starter, there are a lot of recipes in “Sourdough”—in the book—that you can incorporate it into. Not as a leavening agent, but just as another ingredient.
Q. Owing to your botanical passions, a lot of your recipes have plant flavors. For instance, there’s not just a chocolate cake, but a Chocolate Chipotle Kumquat Cake, which sounds incredibly extravagant and complex-flavored. Or a Pear and Buckwheat Cake. There is a Sun Dried Tomato Shortbread, and a beetroot chocolate cake. [Shown above: Fiddlehead pizza.] I know that some of those ingredients aren’t in season right now, but what flavors are you incorporating at the moment in your kitchen?
A. A lot of the ingredients I use now are either things I have preserved earlier in the season, like dried rose petals, or dried fennel seeds, or lilac sugar—which I have a wonderful recipe for.
Q. Lilac sugar!
A. It’s wonderful with fresh fruits like blueberries. I also look to ingredients that are always in season, like dried nuts and fruits, chocolate—those sorts of things.
Q. There was a recipe for a seeded turmeric and leek bread that was beautiful, with a gorgeous golden color. There is so much to try in the book, and I’m appreciative of your taking me through how to create my own personal Jabba the Hutt, Sarah, over here in my kitchen.
win a copy of ‘sourdough’ by sarah owens
I’VE BOUGHT an extra copy of “Sourdough: Rustic Recipes for Fermented Breads, Sweets, Savories, and More” for one lucky winner. All you have to do to enter to win is answer this question, entering your reply into the comment box at the very bottom of the page, scrolling down beneath the last reader comment:
Do you bake…and if so, any experience with sourdough as a baker (or an eater)?
Feeling shy, or have nothing to share? Just say “count me in” and I will include your entry–again, put it in the box-like form at the bottom of the page! Good luck to all. I’ll choose a winner at random after entries close at midnight Sunday, February 28, 2016.
prefer the podcast version of the show?
MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its seventh year in March 2016. In 2016, the show won three silver medals for excellence from the Garden Writers Association. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the Feb. 22, 2016 show right here. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
sarah owens’s sourdough starter
(Excerpted from “Sourdough,” by permission of Roost Books.)
AN INTERESTING way to create a starter from scratch involves using raisins to create yeast water. I call the resulting starter the Mother because it will give birth to many different recipes. The following measurements require a kitchen scale that will ensure you are able to create and also feed your starter with ample amounts of flour and water.
Two 1-liter lidded glass or ceramic containers
685 g filtered water
150 g granulated sugar
65 g raw honey
225 g organic raisins (not treated with preservatives)
175 g bread flour
In a saucepan combine 570 g of the water and the sugar over low heat just until dissolved. Once cool, stir in the honey and add to one of your containers along with the raisins. I prefer to use glass containers with a latch top. Seal and place in a warmish location (70 degrees or warmer) of your kitchen. On top of the refrigerator is often a nice spot—just don’t forget about it!
Give the mixture a thorough shake several times a day and pop the top to allow for adequate air exchange over the next 5 to 7 days. After day 3 or 4 (depending on the ambient temperature of your kitchen) you’ll begin to smell the presence of alcohol. The lid will pop when you open it, releasing carbon dioxide as a by-product of fermentation. This means fermentation is moving along as it should and you are on your way to a happy Mother! Leave the jar loosely covered with a lid at this point, allowing the mixture to “breathe.”
After day 6 or 7, you should observe bubbles actively rising to the surface. This is an indication that your yeast water is ready. Add 60 g of this yeast water to 60 g of the bread flour in the other container (this is the jar that will house your starter). Stir until thoroughly mixed, and leave covered with a loose lid at room temperature for 8 hours or overnight. After this initial mixing, small bubbles will indicate signs of life. Add the remaining 115 g water and the remaining 115 g flour, position the lid, and allow to ferment at room temperature for another 8 hours.
You now have your own Mother, kept alive by feedings of equal parts flour and water by weight. After several more feedings, when you drop a tablespoon of starter in a glass of water and it floats instead of sinks, your starter will be ready to leaven bread. Remember, once fed, your starter will double in size. Keep it in a container that will accommodate this expansion.
I like to keep about 150 g to 300 g of starter on hand at all times. If you bake less, you may only need half of that. Always refresh (feed) your remaining starter after using it in a recipe with an equal weight each of water and flour. If you are only an occasional or weekend baker, the refrigerator is the best home for your starter but will need to be refreshed (fed) twice before it will be strong enough to leaven bread dough. If you need to discard some of the starter to make room for a feeding, consider using it in one of the many recipes from my book Sourdough that uses starter as an ingredient rather than a leavening agent.–Sarah Owens
(Photographs courtesy of Roost Books, from “Sourdough;” used with permission. Disclosure: Purchases from Amazon affiliate links yield a small commission.)