Updated: Oct 20, 2020
I started baking sourdough a little over a year ago, and during this pandemic Sourdough bread has certainty risen in popularity. One of the beautiful parts of sourdough bread is that every time you discard you starter, someone else can take it and begin baking their own loaves!
In a nutshell, sourdough is slow-fermented bread. It's unique because it does not require commercial yeast in order to rise. Instead, it's made with a live fermented culture, a sourdough starter, which acts as a natural leavening agent.
Although it has comparable nutrients to store bought bread, it has some qualities that categorize it as superior to store bought bread such as:
· pre-digesting starches, making the bread more easily digestible
· lowering insulin response/improving glucose tolerance
· protecting Vitamin B1 from the damage of the heat of baking
· breaking down gluten, which may result in a bread that gluten-sensitive people can eat
· activating phytase to hydrolyze (dissolve) the phytates, thus freeing up minerals:
* Lastly, it’s just plain delicious!
So, we know that sourdough is a slow fermented bread, but what exactly is Sourdough Bread?
It's believed to have originated in ancient Egypt around 1,500 BC and remained the customary form of bread leavening until baker's yeast replaced it a few centuries ago.
Sourdough is an old form of bread leavening. It relies on a mix of wild yeast and lactic acid bacteria that are naturally present in flour, rather than baker's yeast, to leaven the dough.
On average, one medium slice weighing approximately 2 ounces (56 g) contains:
Carbs: 32 grams
Fiber: 2–4 grams
Protein: 6 grams
Fat: 2 grams
Selenium: 22% of the RDI
Folate: 20% of the RDI
Thiamin: 16% of the RDI
Sodium: 16% of the RDI
Manganese: 14% of the RDI
Niacin: 14% of the RDI
Iron: 12% of the RDI
Sourdough's basic nutrition profile resembles that of other breads, but it has a few special properties that make it more nutritious because the fermentation process improves its nutrition profile in several ways.
Sourdough Bread contains Lactic Acid Bacteria
For starters, whole grain breads contain a good amount of minerals, including potassium, phosphate, magnesium and zinc.
Unfortunately, the absorption of these minerals is limited by the presence of phytic acid, which is commonly referred to as phytate.
Phytates are considered antinutrients because they bind to minerals, reducing your body's ability to absorb them.
Interestingly, the lactic acid bacteria found in sourdough bread lowers the bread's pH, which helps degrade phytates. This results in a bread that has a much lower phytate content than other types of bread.
One study showed that sourdough fermentation may reduce the phytate content of bread by 24–50% more than conventional yeast fermentation.
Lower phytate levels increase mineral absorption, which is one of the ways in which sourdough bread is more nutritious than conventional store bought bread.
Moreover, studies show that the lactic acid bacteria present in sourdough bread have the ability to release antioxidants during sourdough fermentation.
Sourdough fermentation also increases folate levels in the bread, although levels of certain nutrients like vitamin E may be slightly reduced in the process
Finally, sourdough's longer fermentation time helps improve the flavor and texture of whole grain bread. This may make people more likely to opt for a whole grain bread, thereby promoting a higher consumption of fiber and nutrient-rich breads.
Sourdough has Probiotic Properties
Sourdough bread is often easier to digest than bread that's fermented with brewer's yeast. Researchers believe this could partly be due to sourdough bread's prebiotic content and probiotic-like properties.
Prebiotics are non-digestible fibers that feed the beneficial bacteria in your gut, while probiotics are beneficial bacteria found in certain foods.
Regularly consuming both may help improve your gut health, easing digestion.
Sourdough fermentation may also degrade gluten to a greater extent than baker’s yeast making it easier to tolerate for individuals sensitive to gluten.
Research has shown that the sourdough fermentation process may also help improve the taste, texture and nutrient availability of gluten-free bread.
However, keep in mind that sourdough fermentation does not degrade gluten completely. Sourdough bread containing wheat, barley or rye should be avoided by people with gluten intolerance or celiac disease.
Sourdough Bread has a lower Glycemic Index (GI)
Sourdough bread may have a better effect on blood sugar and insulin levels than other types of bread, though the reason for this isn't yet fully understood.
Researchers believe that sourdough fermentation may modify the structure of carbohydrate molecules. This reduces the bread's glycemic index (GI) and slows down the speed at which sugars enter the bloodstream.
The GI is a measure of how a food affects blood sugar. Foods with a lower GI are less likely to produce a spike in blood sugar levels.
In addition, the lactic acid bacteria found in the dough produce organic acids during fermentation. Some researchers believe these acids may help delay stomach emptying and prevent a spike in blood sugar in a way similar to vinegar.
The sourdough fermentation process is often used to make rye breads, as rye does not contain enough gluten for baker's yeast to work effectively.
One study showed that participants who consumed rye bread had a lower spike in insulin levels than those given the same amount of conventional wheat bread.
In addition, several other studies compared participants' glucose response after eating sourdough bread and bread fermented with baker's yeast.
Overall, participants who ate the sourdough bread had lower blood sugar and insulin levels than those who ate the breads fermented with baker's yeast.
As you have read, there are many health benefits to sourdough bread. It does take a commitment to make as you have to feed your starter weekly if you retard it in the fridge, or daily if you keep it on the counter. The process of baking the bread from start to finish takes 16+ hours. But in my opinion, it is worth it for the taste alone.
Baking sourdough bread has been also therapeutic for me over the last year. It has given me a new perspective of bread every time it is mentioned in the bible. There are so many different recipes and variations of sourdough to keep it interesting. One of my favorites is an Caramelized onion, asiago cheese, Italian herb sourdough bread! You can also make different types of baked goods with your bread. This past easter I made cinnamon rolls!
Do you have any additional thoughts or want to try baking sourdough? Shoot me a message at email@example.com