Naturally Leavened Bread The french word levain is derived from the Latin levare: to rise. Pain au levain, levain bread, sourdough, naturally leveaned bread: same concept, endless interpretations, some good, some outstanding, some bad. The myths are plentiful, the methods endless. A number of bread books detail methods for starting a levain, or sourdough culture, from apples, organic grapes, honey, and other yeast-friendly hosts to inseminate the flour. They fall prey to the bane of many formula books: a step-by-step process without a good explanation of what’s going on; what happens when you do this, that. What you need to know is that the way you feed your starter controls yeast reproduction, fermentation, bacteria production, and acidic properties. You learn as you work with it and use it in your breads. My suspicion is that most bakers just follow instructions by rote and never develop a ‘feel’ for how to manipulate the levain to achieve a particular result. I remember when I was first interested in developing a sourdough culture, I read from a well known book on artisan baking about wrapping a bunch of organic grapes in cheesecloth and immersing them in a flour and water mixture. Unable to find organic grapes, I gave up. I took my first class in Artisan Baking at the San Francisco Baking Institute, where we developed sourdough cultures from rye flour and water. After several days of feeding the culture twice daily with rye and water, and storing in a warm place, we had an actively fermenting and powerfully aromatic culture that served as a base for the wheat flour sourdough culture I have today. According to Didier Rosada, Bread Instructor at the National Baking Center in Minneapolis, the leavening culture (or chef, or starter, or sourdough) contains a variety of yeasts that are present because they live in an environment that is ideal for their survival and reproduction. Grape yeasts live on grapes because that’s the environment that suits them, not a flour environment, and it’s not how or when the culture was begun but how it’s maintained that determines it’s performance and flavor profile. Natural selection will rule in the flour environment. The addition of grapes, apples, etc., to the starter simply provides sugars for fermentation. Malt would do the same thing, providing food to the yeast. Many of the micro-organisms involved in the start of a culture won’t tolerate the environment as the culture develops; only those that thrive in the culture that is developed and maintained will survive. A levain culture can be fully developed and mature in a matter of just a month or two. But I digress. Traditionally called sourdough in the U.S., naturally leavened bread is based on a family of yeasts that occur within the flour and that exist in the local environment and pass in the air. Commercial yeast, found in dried form or in moist cakes, is by contrast a mono-culture, or a single strain of yeast, and was introduced into commercial baking in the 1800s, first in liquid or cake form as brewers yeast, and later in dried form. Prior to the use of mono-culture yeasts, all leavened bread through the millennia got happy from what we now call natural leavening, or sourdough, a term that leads to confusion. Natural leavening allows multiple strains of yeast to co-exist in a common culture, and gives the baker an opportunity to create a bread and other leavened baked goods with a more complex aroma and flavor, and much better shelf life. The character of the naturally leavened bread, whether sour and tart, vinegary, milky, or mellow and complex, depends on how the culture is fed and maintained, how much is added to the dough mix, and how long it is allowed to ferment and at what temperature. The yeast community in the culture is billions of rapidly reproducing, gas belching, single celled organisms. They need food! Regularly! Bakers feed their levain cultures anywhere from one time each day to every two hours. Consistency in the feeding schedule is needed to produce a consistent product. Yeast is a living, single-cell organism and a single hard-working yeast will divide more than a dozen times before it dies. In the right environment, these divisions and the divisions of all of the offspring will produce millions of yeast cells. And that’s from just one yeast cell, so you can imagine how quickly a community of yeast cells will reproduce and consume all the food available to them, in the form of simple sugars (complex sugars in the flour starch are broken down by enzymes into simple sugars that the yeast feed on). My intentions are to avoid referring to my naturally leavened breads as ‘sourdough’ because too many people associate ‘sourdough’ with breads that are indeed sour in flavor and leave a sharp, vinegary aftertaste. But I usually fail, because anytime I say naturally leavened most people don’t get it. A San Francisco baker says on his website that in France a bread that is too sour is a fermentation mistake, while in San Francisco, it's a very well-appreciated taste. It is a matter of taste, but compatibility with what it is served with can follow similar rules to how wine is served with meals; lighter, more subtle character wines with lighter, delicate foods, although a lighter bread such as a baguette can also work well with more assertively flavored meals too. It is rare in France to find a pain au levain that has the sourdough taste that is fairly common in American breads. My preference is for a mellow, complex flavor of wheat and fermentation. The real art, or craft, of baking with a levain culture, is in producing a consistent product with complexity derived from fermentation, much as the winemaker’s craft comes from doing the same with grapes and their naturally occurring yeasts. Winemakers often supplement the yeasts that are native to the crushed grapes with added yeast cultures. To compare the flavor profile of a good levain bread with a straight dough commercial yeast bread is like comparing a good wine with grape juice. Eric Kayser, the youthful, wispy, carrot-topped, and well known 3rd generation Parisian baker says "Good bread is a harmony of aroma and flavor; it smells like wheat and wine. Good bread has a nice crust that’s golden in color, crispy and not too thin. And inside, good bread has holes, big and small holes that are humid." When people think of San Francisco sourdough, their taste memory conjures up a recollection of a tangy, sour, almost vinegary tasting product. For many, this is a good thing. And there’s the old saying that you can only make a San Francisco sourdough in San Francisco, because of the indigenous yeast and bacteria that are native to the San Francisco area. While there are a minor population of yeast and bacteria local to the San Francisco area, and other regions too, the primary flora are the same in all sourdoughs everywhere, and the predominant character of the bread is formed as a result of how the sourdough culture is maintained and introduced into the final dough, and where and how the wheat is grown, harvested, and milled. In my opinion, a bread that is too sour overwhelms whatever it’s served with. But this is the flavor most people think of when they think of sourdough bread. So, while in most circles the term ‘sourdough’ is used synonymously with natural leavening, I try to avoid it. Without success. Contrary to the occasional myth, the character of a sourdough, or naturally leavened bread, has mostly to do with things like how much water is in the culture, what kind of flour is used, the feeding schedule, what temperature the culture, or starter is kept at, and how the starter is introduced into the final dough mixture. The aroma, flavor, and overall character of naturally leavened breads, including the consistency of the product from one day to the next, are a function of the baker’s craft. His or her signature. The true artisan baker is one who understands how to manipulate these small number of variables (that yield an infinite possibility of results) to produce the product they want. The complexity of a levain bread comes from multiple sources: a community of yeasts, instead of a mono-culture; bacteria production; fermentation gasses; and lactic and acetic acids. And time. It’s remarkable how lengthening the fermentation in cooler temperatures adds complexity. Acids are responsible for the sour in sourdough. The vinegary taste comes largely from acetic acid. Lactic acids are common in milk, and indeed give a milky, sometimes fruity, taste. Both acids are often more evident as an aftertaste, unless, like with San Francisco sourdough the sour character is strong and pronounced; and many naturally leavened breads have a flavor profile that leans more to one end of the spectrum than the other. A good artisan baker understands how to ferment dough that has a particular character. San Francisco sourdough is an excellent example of acetic character. In my naturally leavened breads, I aim for a complex aroma and character in the middle of the lactic-acetic spectrum, a mellow nature that makes for a bread that is satisfying by itself or that is complimentary with a variety of foods and wine. It flatters what it is served with. It doesn’t overwhelm. This, to me, is bread that I want to eat every day. I have read that naturally leavened breads compliment meals because they aid digestion, but I can’t back that one up with a credible source. Another myth: many bakers brag about their sourdough that’s been passed down through the generations, and claim its superiority to younger sourdough cultures. "Our starter is 63 years old". Hooey. There is nothing in lab analyses of yeast, bacteria and acids to support those claims. The simplest way to make bread is to mix fresh or dried commercial yeast with flour, water, and salt, let it rise, form loaves, and bake. This is called a straight dough, and it has a simple, straightforward, sometimes yeasty flavor. It is the kind of bread most of us grew up on. It smells great when it’s baking, and bread nirvana used to be melting a pad of butter on top of a just-cut, steaming, aromatic slice of hot bread, straight out of the oven. Then, after it’s cooled, the bread has little to no aroma and modest character, but who cared when it was a platform for bologna and cheese, or peanut butter and jelly?! Unless you were desperate the thought of eating this bread alone was nuts. Remember how it would stick to your teeth?