What is Sourdough?

A beginner's guide to understanding the wonderful world of sourdough.

Sourdough, simply put, is a mixture of flour and water that is fermented and then baked. While it has seen a renaissance across the globe in recent years, the modern world has largely relegated it to the "artisan" or "craft" bakeries, where in truth up until about 150 years ago it was the primary way to leaven bread.

Evidence of bread making stretches back as far as 14,000 years ago in what is now Jordan. Mortar and pestle type setups were found beside large prehistoric stone hearths. Based on trace remains, researchers suggest that our prehistoric ancestors would have smashed wild barley and wheat with the roots of vegetables together, mixed with some water, and baked it on the hearth by the fire, presumably to pair with the wild gazelle carcass roasting beside it.

As agrarianism took root (no pun intended) in Mesopotamia and the Fertile Crescent, cultivated crops like barley and wheat became staple foods, mostly as flatbread or porridge. It was sometime around here, 9,000 years ago as evident in what is now Turkey, that people started to allow the porridge to sour, or ferment (same process as making alcohol, actually) and ultimately baking it.

It must have looked like magic to watch sticky sludge grow and morph into a hard brown rock in their ancient oven. Not to mention the flavour changes dramatically. The debate continues as to whether the initial inspiration for settling into agrarianism was for a stable food source like wheat and bread or a reliable source of product to turn into beer. We may never know, but if I only had one thing to say to our ancestors, it would be thank you for both.

What makes it rise and taste sour?

Sourdough exists in part for the same reason that beer, cheese, and pickles exist: fermentation. When you mix flour and water together, you're creating an environment that yeast and bacteria love - high moisture and plenty of digestible sugars. In the case of wine it's grape juice, in the case of wheat it's starches. An enzyme called amylase in the flour is activated when hydrated. It's a catalyst that converts these starches into sugars (fun fact: it's also present in saliva and is the very first step in your digestive system!)

Yeast and bacteria are everywhere: on your skin, in the flour, and floating in the air. When you leave that mixture out at room temperature, you've just plopped a veritable oasis in the middle of the desert. Now all the micro-wildlife are rushing to the watering hole to battle it out for a spot. Luckily, the main types of yeast and bacteria that we're looking for not only like the mixture but like each other.

The Saccharomyces and Candida families of yeasts gobble up certain sugars and fart out alcohol and carbon dioxide. Many yeasts do this, but these types love acidic environments, and that's where Lactobaccilli and/or other Lactic Acid Bacteria (LAB) come in. When LAB eat sugar they excrete lactic acid, which lowers the pH of the environment, optimized for these yeasts. As they continue, more carbon dioxide is produced and it gets trapped in bubbles thanks to the tensile strength and elasticity of gluten development, the vital protein that allows bread to rise.

Microbes are our friends

Some people can be put off by the idea that trillions of microscopic bugs are living on your skin, in your hair, and particularly in your gut. If you're one of these people, I'm sorry to say that no amount of hand sanitizer will wipe them out (in fact, using too much has shown to develop superbugs immune to such sanitization). More and more evidence has shown how reliant our health is on having an active, robust community of yeasts and bacteria living on and inside us (this is referred to as our microbiome). Eating foods that nourish these yeasts and bacteria in our gut have shown to improve our immune system, nutrient absorption, and even mental health!

We're encouraged to incorporate living fermented foods like kimchi and yogurt into our diets for a couple reasons: we're increasing the community of beneficial microbes, and we're putting food into our bodies that have already been partially broken down, easing the ability to absorb nutrients that would have been locked away.

When we make sourdough, we're using these microbes to break down something that is pretty hard on our bodies. Our digestive system is relatively short compared to a lot of mammals, and things in the grass family - like wheat - can't spend enough time in our system to have any kind of nutritional value. In fact, it can even hurt if we consume enough raw wheat. There are many methods we've employed as a species to break down foods like this: roasting it over a fire, boiling it, soaking it, malting it (the process of letting it sprout a little and then drying it out quickly to stop the process from continuing), and finally smashing it, mixing it with water, and cooking it. If you let that mixture sit out for awhile, microbes begin to eat it. We like that. We like that a lot. We let them do the digesting for us, then we bake it and dip it in stew.

But if we bake it don't we kill all the living microbes?

Great question: yes - BUT their legacy lives on. You see, while there are no living microbes in a loaf of baked sourdough, all the things that made flour hard to digest have been broken down, and so many more nutrients have been unlocked for us and our microbiome to absorb.

What's the beef with commercial bread?

Shortly after Louis Pasteur introduced the world to the idea of trillions upon trillions of microscopic bugs living all around us, people began to isolate different strains of yeasts and bacteria. They were able to pull out one strain of Saccharomyces that produced the most amount of carbon dioxide and packaged that as an "instant yeast". Now, bakers could just add this isolated strain of yeast to their dough and POOF! What was once an all-day-overnight project had been shortened into the short span of a couple hours. Traditionalists abhorred it, but more and more bakers began incorporating this instant yeast into their breads, increasing production, predictability, and profits.

But this speedy bread was different. While the dramatic and airy crumb was appealing, it didn't have the same deep flavour as their sourdough counterparts, and it staled and molded much quicker. Commercially, these were important factors that needed to be addressed. So industrial bread factories began to add things to the bread to make it taste better like fats and sugars. They added chemical preservatives and stabilizers to extend it's shelf life, flavour perceptibility, and anti-staling properties. A simple product and staple in so many peoples' diets made of 3 ingredients and slow fermentation had now been hijacked and turned into a quick commercial commodity.

In addition, by omitting the long fermentation process, the wheat couldn't be enzymatically broken down enough to be easier on our digestion, suggesting it's contribution to the rise in reports of gluten intolerance in the mid- to late-20th century.

That being said, we're not saying ditch the hotdog buns. There's a time and a place (and an amount!) for nearly everything, but to replace something so significant to so much of human history, diet, and culture, with something so devoid of substance and potentially harmful in large amounts, is truly a sad reality of the modern world.

Thankfully, this doesn't mean you have to buy $8 loaves of sourdough from your towns craft bakery every few days. You can buy an $8 bag of flour and make 10 loaves over the course of months! That's power to the people right there!

Flour, Water, Salt, Time

You'll probably see us say this a lot here, but it really is that simple. If you want to get started, you really just need a bag of flour and some time set aside. It always feels like we don't have enough time in this world, but when you're starting out, try to think of it as a weekend project you can do with the family or friends or just as a solo project. There's more down time than active time - which, if we're being honest, was a huge draw for us - and once you make a strong starter, you have the power to make nutritious and delicious bread for you and the people you care about.

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