The Definitive Guide to Fermented Foods

Life in the Paleolithic wasn’t a pristine, sterile existence. There were no fun-sized hand sanitizers or pasteurized eggs. Meat didn’t come shrink-wrapped, and it wasn’t stored in sub-40 degree temperature to prevent spoilage. I’ve never seen evidence of vegetable cleaning liquid containers at prehistoric dig sites, nor have any tiny tubes of antibiotic ointment been discovered among the arrowheads, flint shards, and stone spears. In fact, for the better part of human history, man was entirely ignorant of the existence of microorganisms, let alone the crucial role they played in our everyday lives. The Roman scholar Marcus Terentius Varro, in his 1st century BC book “On Agriculture,” wrote of “certain creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and there cause serious diseases,” but he was just guessing (the Romans used a pseudo-soap to occasionally remove sweat and visible grime, but not for any supposed anti-microbial effects). It wasn’t until the 17th century that microorganisms were even discovered, and it took another couple hundred years for us to realize that the little guys could cause disease and that boiling or sufficiently heating a substance could kill or mitigate the worst of them.

Like always, though, we went a bit overboard. Deaths from easily preventable infectious diseases plummeted, and it became an all-out war on the sub-visual world. Germs, bacteria, microorganisms – they were all out to get us, and totally eradicating them from our daily lives became paramount for optimum health. Nowadays, everything is pasteurized – food producers are proud to mention it, kinda like the “low-fat” label – and everything that might touch a bodily orifice – hand, utensil, small child – is doused in anti-bacterial soap followed by regular applications of hand sanitizer. If it’s a general truth that people fear the unknown, I can’t think of a more salient example than our irrational, seemingly innate fear of these tiny organisms we cannot see.

Now, I won’t argue that given the current state of our food system, paying attention to cleanliness isn’t important. It is. I wouldn’t feel comfortable drinking raw dairy products made from grain-fed cattle wading through rivers of their own toxic feces, and I’d be wary of eating a blood rare steak produced from the same cows in a filthy, heavily impacted slaughterhouse staffed exclusively by underpaid, overworked personnel. With our current industrial agricultural standards, I can only imagine the incidences of e. coli and other food-borne illnesses would skyrocket if they weren’t pasteurizing and irradiating everything.

I’m just saying that a little microorganism might be beneficial. And if you consider the environment in which we humans did the bulk of our evolving and adapting, perhaps a bit of bacteria (food borne and otherwise) in the body is a vital component of healthy living. I mean, if we accept the premise that the circumstances of our early evolution can inform current practices, dietary and otherwise, doesn’t that mean getting dirty and eating beneficial bacteria is part of that? I think it does.

Enter fermented foods.

People have been eating bacteria ridden foods for hundreds of thousands of years. Grok certainly happened across rotting fruit or an old carcass from time to time, and even his fresh meat and vegetation weren’t scrubbed clean, pasteurized, or irradiated. Life was “impure,” even dirty by our standards, and there were infectious diseases – but at least we were somewhat equipped to deal with them because of the seamless integration of bacteria and other microorganisms into our lives. So, while Grok may not have been actively fermenting foods (though he did employ unconventional meat storage methods that probably presaged fermentation), he was consuming plenty of bacteria on a regular basis.

In most post-agricultural peoples, some form of fermented food is a standardized component of the traditional diet. The earliest sign of wine dates from about 8000 years ago, in Georgia (Caucasus, not the state north of Florida), and there’s evidence that people were fermenting drinks in Babylon circa 5000 BC, Egypt circa 3150 BC, Mexico circa 2000 BC, and Sudan circa 1500 BC. Fermented, leavened bread was produced in Ancient Egypt, and milk was fermented in early Babylon as well. Roman soldiers often subsisted on long-fermented sourdough bread, which survived long treks well (imagine conquering the known world on a diet of bread – fermentation must be pretty effective stuff). The Inuit traditionally wrap whole seabird carcasses in seal pelts and bury them underground to ferment for months; rotting fish is another feature of their traditional diet. Fermented dairy is a major aspect of the traditional Masai diet, as is clotted steer’s blood.

The list goes on and on: East and Southeast Asia with natto (fermented soy), kimchi (fermented cabbage), soy sauce, fermented fish sauce, fermented shrimp paste, to name just a few; Central Asia with kumis (fermented mare milk), kefir, and shubat (fermented camel milk); India and the Middle East with fermented pickles, various yogurts, torshi (mixed vegetables); Europe with sauerkraut, kefir, crème fraiche, and rakfisk (salted, fermented trout); the Americas with kombucha, standard pickling, and chocolate; the Pacific region with poi (fermented, mashed taro root) and something called kanga pirau, or rotten corn.

There’s gotta be something to it, right? Everyone’s doing it (or, at the very least, everyone used to do it)! Perhaps we should, too. The Standard American Diet is definitely missing fermented food – unless you count cheap beer and box wine, of course. Even when we do eat foods that are traditionally fermented, like sauerkraut or pickles, they’re usually bastardized versions produced quickly for mass consumption. Most sauerkraut you can buy in the store, for example, is flaccid and mealy, rather than crunchy and tangy as it should be. That’s because most commercial sauerkraut (and pickles, for that matter) is preserved in vinegar instead of the traditional (and naturally occurring) lactobacterial-salt slurry. Unless the producer adds bacteria, store bought sauerkraut is usually pasteurized and bereft of taste and nutrients. Instead, get or make the real stuff.

But wait. What, exactly, are the health benefits of eating fermented food? For one, (and this doesn’t apply to a PBer, but it still deserves mention) fermentation can render previously inedible or even dangerous foods edible and somewhat nutritious. The lectins, gluten, and phytates in grains, for example, can be greatly reduced by fermentation. I don’t advocate the consumption of bread, but if you’re going to treat yourself to any gluten grain-derived food, make real, long-fermented sourdough bread the one. The Romans managed to do okay on the stuff, but that’s only because meat was expensive and didn’t travel as well. Real sourdough is a good choice for guests who simply must have their bread, but don’t think fermentation makes it Primal approved.

Dairy is another beneficiary of fermentation. In fact, next to no dairy at all, I put fermented, raw, grass-fed dairy as the optimum form. The fermentation process breaks down the lactose, thus mitigating a potentially problematic sugar and decreasing the carb content (you can consider the official carb count of real yogurt cut in half; producers list the number of carbs present in the dairy before fermentation, and the fermentation process breaks down the lactose/sugar).

Before they’re turned into delicious, rich dark chocolate, cacao beans must first be fermented. This deepens the color and enriches the flavor, but most importantly it destroys the astringent tannins present in raw cacao. Tannins lend a bitter flavor, and some people have bad reactions to tannins. If you’re overly sensitive to red wine and get headaches when you drink it, tannin sensitivity may be responsible. The best dark chocolate is the product of long-fermented cacao beans with most of the tannins removed.

Even soy becomes somewhat tolerable with proper fermentation. Natto, a Japanese form of fermented soybeans, is high in Vitamin K2 (MK-7), which is vital for bone, cardiovascular, and dental health. Again, I’m not advocating soy consumption, but rather highlighting the ability of fermentation to transform an undesirable food into one with some undoubtedly redeeming qualities.

Speaking of K2, fermentation also makes it available in a few, more Primal foods. Aged raw milk cheese has ample amounts of K2 (MK-4 form), as do grass fed liver and raw butter. It all comes down to internal fermentation: the cow eats the K1 rich greens, the gut fermentation produces the K2, and we get the K2 by consuming the liver or certain high fat dairy products made from the cow’s milk. I suppose we could probably get a bit from the half-digested stomach contents of a pastured cow, but I’d rather just stick with sauerkraut for my fermented veggie fix.

Even if you aren’t looking for ways to mitigate the damage from Neolithic food like dairy, grains, or soy, fermented foods confer other benefits. For one, fermented foods introduce helpful probiotics to our guts. There are tons of possible benefits to adding probiotics (whether by supplement or by fermented foods like dairy) to your body, including protection from colon cancer, relief from lactose intolerance and rotavirus diarrhea, reduction in children’s cavities (more vindication for Weston Price), and prevention of reoccurrences of inflammatory bowel disease. The vitamins (like K2) in fermented foods like kefir become more plentiful or more concentrated (either by breaking down the food or by virtue of the bacteria outputting more nutrients), and more bioavailable. Also, the improved digestion that accompanies a healthier gut means more nutrients, vitamins, and minerals are absorbed (and if you’re eating a usually phytate-rich food, the fermentation can really break down the mineral-binding phytates), thus allowing even better absorption.

I suspect that the benefits of fermented food aren’t stemming from some magical property inherent to fermented food, but rather the simple fact that introducing beneficial bacteria into our bodies restores the balance of intestinal flora that used to be standard in people who ate traditional, whole foods Primal diets and exposed themselves to bacteria on a regular basis. Fermented foods merely address a severe deficit in the modern gut; they don’t introduce anything new to human physiology. Despite our best attempts to recreate perfect Primal environments through diet and exercise, we still live in an increasingly sterile world. Introducing fermented foods into our diet can help normalize things and get our guts in good shape.

As for what types of fermented foods are best, I’d stick with mostly Primal stuff to be safe. Sauerkraut is great, and if you can tolerate dairy, go for full-fat Greek style yogurt (high in saturated fat and protein, low in carbs) or strain your own yogurt (much of the sugars are in the liquid whey). Kefir is another possibility, as are aged cheeses. You could even make a batch of traditional Roman fermented fish sauce: salted, liquefied sardine and anchovies fermented with herbs and spices in the hot sun for months at a time. Kombucha makes for a great refreshing drink; just make sure you watch the sugar content.

People have been eating fermented foods for thousands of years willingly, and even longer accidentally. The evidence shows there’s definitely something to it, and I think it can be a vital part of a healthy Primal Blueprint diet.

What about you? Any fermented favorites you’d like to pass along?

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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