Art and Science of Sourdough
Maybe I am a little late into the game of sourdough baking, but the slow and serene process of micro farming, (cultivating and tending the starter) any given day, provides immense satisfaction and joy. Sourdough bread is one of the oldest biotechnologies, coupled with chemistry, used to prepare nourishing wholesome bread with just three ingredients, flour, water and salt, compared to the 15-ingredient generic white bread.
Why is sourdough bread so unique in flavor, good for health and satisfying to the soul?
The secret answer is the unique combination of wild yeast and lactobacilli. There are two kinds of yeast that can leaven or raise your bread. Baker’s yeast, cultivated in a chemist’s laboratory and sold in packages like over-processed food, usually contains saccharomyces cerevisiae. Wild yeast grows naturally when the food is allowed to ferment for a certain period of time and contains many different strains of yeast. Both the baker’s yeast and the wild yeast act similarly on bread flour, and convert scratches and sugars of grain into carbon dioxide, resulting in air pockets that make the dough double or triple in size. Wild yeast cultures go above and beyond just raising the bread; it uses healthy lactobacilli bacteria to convert notorious big protein molecules (like gluten) into lactic acid that gives sourdough a distinct flavor.
Decrease gluten content: Fungal proteases and selected sourdough lactobacilli digest the wheat flour, which might be safe for some of the gluten intolerant population.
Increased mineral uptake: Fermentation process reduces the pH, which breaks the phytate responsible for hindering the mineral absorption.
This lactic acid acts as a superhero and allows the phytic acid content to be lowered so minerals can easily be absorbed from the bread. It almost acts as a predigested food for us so most minerals that remain inaccessible to us are unlocked and we can enjoy full benefits of whole grain. One research study published in the Journal of Agriculture and Food Chemistry concludes that sourdough fermentation reduces the phytate content by 24-50 percent.
Low glycemic Index (GI): Sourdough fermentation may decrease the glycemic response of baked goods. A slice of sourdough bread has a GI of 53 in comparison with white bread, which has a GI of above 70 (glycemic index is measured from a scale of 1-100; lower glycemic index foods are recommended for better health). Several research studies, particularly one published in American Journal of Clinical Nutrition, backs this idea, but one of the recent studies conducted with about 20 subjects presents the notion that the GI of the bread really depends on the microbiome, so the GI response would vary.
Improved antioxidant activity: The long fermentation process releases lactic acid, which acts on cereal protein (proteolysis-breakdown of protein) resulting in formation of peptides rich in antioxidant activity.
Dietary fiber and phytochemicals become more bioavailable due to prolonged fermentation.
Regular bread dough is loaded with sweeteners to produce bakers’ yeast (single strain lab manufactured). So, the yeast is no longer breaking down grain sugars because it is happily feeding off the sugar (high fructose corn syrup, molasses, etc.). This translates to an altered chemical composition of a final bread product – higher sugar content, tougher indigestible starches, and loaded with one strain of yeast. Without the good old lactobacilli (part of wild yeast), grain proteins and starches, fructans, gluten, were now unchanged by the fermentation process, leaving them fully intact and hard to digest. As sugar becomes the fermentable ingredient instead of flour, nutrients that once became bioavailable due to a long fermentation process remained unavailable.
Considering the pros for this awesome bread, let’s explore how to create this magic. It's quite simple to make sourdough bread!
Sourdough bread recipe:
Using a food weigh scale, measure 100 gms of sourdough starter, 200 gms water and 300 gms of flour (you can mix and match bread flour and whole wheat flour), add 1 tsp salt and mix gently.
If you have a bread machine you can put everything in the bread machine at the sourdough starter setting. Let the dough rise for about 3-4 hours.
Mix once more from bottom to top and side to side don't knead like a regular dough; otherwise, air bubbles will break.
Let it rise further for about 3 hours.
Preheat the oven to 400 degree Fahrenheit.
Optional – you can season the dough after it has risen with any herbs, seeds, cheese, pepper, oil, vegetables, etc.
Proof the dough by folding it again from bottom to top and side to side for about 20 minutes in a bread pan treated with cooking spray or oil. Cover the dough.
After 20 minutes, uncover the pan and bake the bread for about 35 minutes on the second last rack. Measure the internal temperature of bread with a food thermometer; it should be about 195-200 degrees Celsius. Cool it on a cooling rack.
Bhavi Nirav is a certified Iyengar yoga teacher, Registered Dietitian/M.S., R.D., L.D., and can be reached at firstname.lastname@example.org