Why is sour dough bread so popular?

For thousands of years, bakers have had two choices when choosing bread. They can use yeast floating on the top of beer cans, which contains a lot of active yeast cells, or they can create a culture to preserve yeast between one batch of dough and another batch of dough. Some systems use so-called levain, which is a piece of dough covered with salt. Others use wet culture, which we now call sour dough.

In most countries, traditional sour dough will never go out of fashion. France is famous for its sour dough, which is full of rich flavor. Germany, Poland and other eastern European countries use dough to make dense and chewy rye bread, because their climate is not conducive to wheat planting than warm places. In the hometown of Actinobacillus in San Francisco, this bacterium gives local yeast a unique and delicious taste, and yeast has never been out of date. This is part of their colorful local history and a good way to sell expensive bread to tourists.

There is another advantage of cultivating sour dough. Let it stand for a while, and a thick layer of nails will form at the top. When yeast eats carbohydrates, it will produce by-product alcohol. Most bakers either stir it back into the culture medium or pour it in before updating the dough.

American bread is really depressing. The discovery of industrial processes to speed up production, replacing healthy whole wheat bread with refined white flour, and if you bake bread at home unusually, you can easily open a bag of active dry yeast from the supermarket, all of which led to the death of sour dough after World War II. The mass production and packaging of various foods have greatly increased, and only a few people have retained the skills, information and actual culture of making dough. It is more convenient to sell sliced bread in plastic bags than it sometimes takes several days to make high-quality bread.

Fortunately for us, there are a group of serious bakers, die-hard amateurs and simple home cooks who insist on learning this knowledge and making bread in the right way. Fortunately, sour dough is not easy, but it is easy to get. Everywhere on the earth, there are wild yeast and lactic acid bacteria in the air and on the surface. Well, maybe not in Antarctica. Yeast exists on the surface of almost every plant.

Sour dough is popular for many reasons. It tastes better, smells better and has a better texture than the bread in the supermarket. It is rich in flavor and can be used with all kinds of salty food. There are many kinds of dough, because cultures fed with different flours will produce different flavors, and different kinds of wild yeast and bacteria will produce different effects. The dough fermentation time can be used to control the consistency of bread. Sour dough is also a challenge, and serious bakers like challenges. We use fermentation time and temperature to knead and shape dough in different ways, and use the temperature of the oven to get perfect bread.

People exchange yeast cultures with the same enthusiasm, just as readers exchange paperbacks. The culture I grew up in Brooklyn will be different from another baker who started in Wisconsin. A culture with a history of ten, twenty or fifty years will be very different from the culture I started six months ago.

People are used to eating more good bread. Why? Because good bread is a beautiful thing. It has depth and texture and food scientists call it taste. Chewy, not soft or tasteless. It produces flavor through long-term fermentation, rather than adding too many flavoring agents such as salt and sweetener. Sour dough is another flavor, which is a rich and almost acidic taste obtained by many commercial bakeries by adding vinegar to dough instead of using actual sour dough culture. Why? Because, like anything worth doing, sour dough takes time.