On April 22nd, Jeremy and Scott from HiveBio teamed up with Blaine and Leslie from Ada’s Bakery for a Fermentation Workshop on Sourdough Bread and Science! They began with a short history lesson on the age-old, natural process of fermentation. Somewhere along the evolutionary line, humans (along with many other animals) experienced the health benefits of consuming fermented foods. The living, healthy bacteria that thrive in certain fermented foods promote healthy digestion, contributing to the overall well-being of the animal lucky enough to consume them. Some of the most popular fermented foods include yogurt, some cheeses, beer, wine, sauerkraut, and the topic of the workshop, sourdough for making bread.
While Blaine and Leslie did a walk-through of how to prep your own sourdough starter (the directions for which are available at Ada’s and at the links below), beginning with a “pre-ferment” that will eventually lead to your cultivated “sourdough mother,” Jeremy and Scott provided some insight into the chemical reactions that are taking place. A pre-ferment is made of bread flour, rye flour, a culture (a small amount of yeast or natural yeast stimulated by something like grapes) and water. The goal of the pre-ferment is to produce Lactic Acid Bacteria which happens in a 2-step process, beginning with the Aerobic Phase and transitioning into the Anaerobic Phase. During the aerobic phase, anaerobic bacteria use up oxygen, multiplying and increasing the concentrations of organic acids such as lactic acid, acetic acid, formic acid, and succinic acids. This process lowers the pH of the pre-ferment and starves undesirable bacteria in the culture. After the pre-ferment rests for 2-3 days in a covered container, the environment becomes primarily anaerobic, further promoting the growth of good, lactic acid bacteria.
Once the pre-ferment rests for a few days, it needs to go through a process of feeding over a few days to get it ready for making dough. Dough for a loaf of sourdough bread is made with a portion of the mother added to additional flour and water. The ingredients for dough should be mixed together either using a dough hook on an electric mixer, or by hand (with some skill), slowly at first and with increasing speed in order to form gluten. While Blaine used the electric mixer, Scott explained that the gluten is comprised of the proteins in the wheat flour, gliadin, and glutenin. As the dough is mixed, the proteins form linked chains that give the dough an elastic and supple feel and the baked bread its soft, spongy texture. Scott also noted that over mixing the dough causes the protein links to become rigid, resulting in a hard and dense texture as opposed to the desirable soft and spongy.
With the power of TV Magic, Leslie retrieved a pre-risen ball of dough in a container and then showed and explained a technique for making a loaf. By pulling the edges of the dough from the corners of the container to the middle, you can create a seam that will be the place where your dough comes into contact with the pan. This way, the smoothest part of your loaf will be coming out of the top of the bread pan when it’s time for baking. Once the loaf is formed and placed in the pan, it is imperative that you score the top to give heat an easy escape path, mitigating the risk of unplanned bubbling/growths during baking. Jeremy explained how, while baking, the bread under goes a Maillard Reaction, during which the heat of the oven causes a reaction between the organic acids and sugars in the bread. The reaction is what creates the sweet, brown crust on the top of the loaf. A combination of the right moisture levels, temperature, and present bacteria make for a nice, brown crust on the top of the sourdough loaf.
As to be expected, we ended the presentation by breaking (sourdough) bread over some olive oil and vinegar, and washing that down a cup of kombucha. For those looking to go past the surface of fermentation, check out The Art of Fermentation and Wild Fermentation by Sander Katz. If you’re specifically interested in baking, Advanced Bread and Pastry by Michael Suas will take you deep into the world and theory of hot, delicious, bready treats of all kinds. And to get started on your own sourdough mother for baking bread and other sourdough treats, check out the links below!
Sourdough Starter Recipe, Ada’s Sourdough Bread Recipe.