Thursday, December 5, 2013

So, What Is Fermented Food (ie What Can I Eat Next Year)?

Two days ago, I announced that I have a book deal. For one year, I am only eating fermented foods, then writing about it — the experience, what I learn, and why we should all care about the microbes in our lives (and in our guts).

I have spent a good deal of time explaining my book to relatives and close friends in recent weeks, and there is one initial question that pretty much everyone has asked me so far... even my homebrewing friends, who have been fermenting beer for years. I will tell them “the deal” (the premise of the book), and they will nod and say “okay, huh,” and then, after a long pause: “So what is fermented food? Can you eat... bread?”

Well, as it happens, that question is exactly why I’m writing the book, though it’s not the easiest to answer briefly and succinctly. Hopefully I can do a better job of it here, in writing, than I did around the dinner table on Thanksgiving with the accompaniment of my uncle’s sarcastic interjections.

If you brew beer, or even sometimes talk about beer with passionate beer enthusiasts, you probably grasp the basics. When yeast ferment a sugary liquid into alcohol, it’s an easy process to comprehend. But how does one know if a food is fermented? And what does that mean, ultimately? In the broadest sense, fermentation is what happens when we let microbes run wild with our food, transforming it through metabolic processes — essentially eating some of the food before you do, and leaving us the gift of little microbial miracles like alcohol, CO2 and tart lactic acid.  To quote Sandor Katz in his original, quintessential book, Wild Fermentation: “Fermentation is everywhere, always. It is an everyday miracle, the path of least resistance.” That last line is eye-opening, snapping into place our true relationship to the little bundles of calories we call food. What happens to food over time? Something is going to start working at it, and as humans, we have the rare opportunity to guide that process and it use it to our benefit.

Almost all food will inevitably rot — decomposition by microbes, loosely speaking. Fermentation is preservation by select microbes. The distinction is very often blurred, as it’s essentially the same process, but what matters is which microbes you cede control of your food to, and what they do with it. With one process, microbes have a free-for-all, one ecosystem gives way to another, and the food decomposes in the resulting frenzy. With the other, an environment is created which allows a select group of naturally-occurring bacteria and yeast to thwart their competitors, establishing a monopoly over the food, to our great benefit. The food is locked into place, at least for a while. Fermentation is easy — we simply let the inevitable happen, but with just enough steering to produce delicious, healthy results.

The phrase “If you can’t beat ‘em, join ‘em,” comes to mind. We’ve spent great amounts of energy in the last century learning how to preserve food from spoilage bacteria through temperature, chemicals, and vacuum-sealed vessels. But all along — for most of the history of mankind — we’ve already had a simple, reliable technology that preserves food with almost no effort on our part. We’ve been trained to fear the tiny crawly things we can’t see, but so many of them are not just our friends — they have been with us for so long that they have evolved a symbiotic relationship with us, of sorts, and are likely vital for our health.

The second question almost everyone asks me is: “So you’ll be eating a lot of canned stuff?” (Also, almost everyone mentions pickles.) Well, no. Canning is pasteurizing, and pasteurization is meant to kill all living microbes in your food — very much the opposite of relying on microbes to preserve your food for you. Most store-bought, big-brand pickles, for example, are pickled in hot vinegar and then pasteurized — microbes make the vinegar, but had no role in transforming those cucumbers. With many foods, fermentation is simply intuitive. Did microbes make my food? Another way to look at it: fermented foods require some aging period to reach their peak flavor, and continued aging is often a benefit to flavor. With modern preservation techniques, food is merely meant to endure age, not benefit from it. Canned food can survive for a very long time because it is completely dead; fermented food can survive for a long time because it is alive.

Having said that, I want to be clear: this project is not about eating only live-culture foods. That would be a very different thing. While the work of bacteria and yeast is the heart of fermentation — and their continued presence one of the major health benefits of some fermented foods — the state of cooking is not really what defines a "fermented food." Consider bread, inarguably a fermented food; you never eat bread in a live culture form. You ferment dough and bake bread; these two processes unite to create arguably the most important food known to mankind. Throughout the book and the blog, I'll be explaining some of reasons why fermentation may provide advantages and health benefits even if the microbes themselves don't make it into your gut.

So yes, I will still be cooking and baking and frying and sauteing some meals, and I think that's part of the fun and creative exploration. Along with that, the most basic of cooking aids are allowed, such as spices and cooking oils. (I am wondering if olive oil actually counts as fermented, anyway, since green olives themselves are traditionally fermented. Gotta look into that.) However, even these may be largely avoided: cultured butter can be used in place of cooking oil for many things, and spices are often added to vegetable ferments pre-fermentation.

So... what all can be fermented? What exactly will I be eating during this crazy year? A lot of things; too many things to list. Almost anything can be fermented. Some you know already. Some will surprise you. Many you have probably never heard of. Others will rely on some creativity — or at least what sounds like creativity in our modern industrial food system. But as you’ll hopefully soon see, much of our everyday diets are already based around fermented foods, even if most of them have been industrialized and warped from their original form — to the point where we generally don't associate these things with the natural process of fermentation.

Got any other questions? Let me know in the comments!


  1. So...fermented meat? Sandor Katz's story of fermenting meat in Wild Fermentation makes my sadistic side hope the answer is "yes"!

    1. I'm quite nervous about fermenting meat myself, but I suppose I really need to try it. I actually read through Art of Fermentation before Wild Fermentation so I guess I haven't got to that story yet... I'll have to scan through and find it tonight.

      I'm hoping I can find someone does that fermented meat stuff locally. Either a real shop or just some guy, either way, I'd feel a lot better if I was working with someone that knew what they were doing. I think Katz mentions he did a procuitto-style venison at some point; I'd love to try something like that.

    2. Probably the least scary meat option would be traditional kimchi, since it uses a shrimp paste/sauce.

    3. True true, good point. I'm mostly going to be doing (and mostly have only eaten) purely vegetable kimchis, but that would be interesting to try.

  2. Ensure you have a firm grasp on food microbiology with regard to safety. I know that Sandor Katz is a great writer, but a little laissez faire about food safety. Make you're using enough salt/acid/time in every case.

    Definitely a great idea for a book! Fermented foods are the cornerstone of many cuisines, so I'm sure are many avenues to explore.

    1. Thanks Richie, absolutely. I agree that Sandor is very casual in his approach, in a few different ways. I've been studying up pretty intently for a few months now, and feeling comfortable with most easier ferments. Anything a little riskier, like meat, I probably won't attempt without some aid / supervision of a person with lots more experience than me.

  3. Re fermented meat: Real salami is fermented - especially the northern European kinds that are really sour. Beware though, many sausage makers just add lactic acid.


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