Monday, April 27, 2009

Fermentation (not alcholic....) of food.

Fermented food

OK, as you may have noticed this blog is often just a record of things that I come across which I find interesting - generally in the area of fitness, conditioning and diet.

Here is something I've been thinking and reading about a bit recently: the idea of fermented food - think yoghurt, kefir, sauerkraut, pickles - being uniquely healthy.

I think I first came across this idea in Sally Fallon's book Nourishing Traditions, much of which is predicated on the work of Weston Price (who made an extensive study of traditional diets in the 1930s, diets unadulterated by modern processing and diets consumed in societies where there were few of the diseases of civilisaiton). Fallon has a good article on Lacto-Fermentation if you want to learn more.

Stephan has discussed fermentation a bit on his blog:

Healthy grain-based African cultures typically soaked, ground and fermented their grains before cooking, creating a sour porridge that's nutritionally superior to unfermented grains. The bran was removed from corn and millet during processing, if possible. Legumes were always soaked prior to cooking.

These traditional food processing techniques have a very important effect on grains and legumes that brings them closer in line with the "paleolithic" foods our bodies are designed to digest. They reduce or eliminate toxins such as lectins and tannins, greatly reduce anti-nutrients such as phytic acid and protease inhibitors, and improve vitamin content and amino acid profile. Fermentation is particularly effective in this regard. One has to wonder how long it took the first agriculturalists to discover fermentation, and whether poor food preparation techniques or the exclusion of animal foods could account for their poor health.

Seth Roberts - Healthy bacteria

What has realy got me thinking about this has been some of the musings of Seth Roberts. Seth has a fascinating blog built really on his practice of self experimentation (big pdf download)

Anyway one of his recent theories is the Umami Hypothesis.

the idea that evolution shaped us to like umami taste, sour taste, and complex flavors so that we will eat more harmless-bacteria-laden food, which improves immune function. (I pompously call this the umami hypothesis.) It seemed so likely to be true that I started eating more fermented foods: miso, kimchi, yogurt, buttermilk, smelly cheese, and wine. To avoid stomach cancer and high blood pressure, I later cut back on miso, kimchi, and smelly cheese.

There have been other changes, too:

  • After buying meat or fish, I don’t try to get home quickly to put it in the fridge
  • I don’t worry that eggs have been in the fridge for 3 weeks
  • When buying eggs and other perishables, I don’t try to get the freshest
  • I don’t worry about leaving milk out
Bacteria and viruses from other humans pose a threat. This is why we find fecal matter so offensive. It’s why hand-washing by doctors matters. But I believe plant-grown and dirt-grown bacteria are harmless because the substrates are so different than conditions inside our bodies. As for meat-, fish-, and dairy-grown bacteria, I don’t think they are very dangerous. Has anyone gotten food poisoning from yogurt? I keep in mind how much stinky fish the Eskimos ate. Maybe I should do some controlled rotting experiments — leave meat at room temperature for varying lengths of time before cooking and eating it.


Also here:

My idea that we like umami tastes, sour tastes, and complex flavors so that we will eat more bacteria-laden food (which nowadays would be fermented food) is saying that we need plenty of these foods. Why else would evolution have tried so hard to make us eat them? The implication is they should be part of every diet, like Vitamin C. When someone deficient in any vitamin begins eating that vitamin, the deficiency symptoms go away very quickly, within a few weeks, usually. The changes are easy to notice. So the details of what Tucker observed - the speed and size of the improvements — support my general idea that there is a widespread deficiency here that can be easily fixed.

Rotten Fish

His theory is consistent with a lot of the ideas of Stephan and Fallon; they also line up strongly with the hygiene hypothesis.

Seth has a series of fascinating posts of this topic - fermented food - which are well worth skimming through.

Roberts also points out that Steffanson - a hero of my friends in the zero carb world - found that Eskimos would eat a lot of rotten - fermented - fish, and he himself ended up enjoying the dish:

I had become as fond of raw fish as if I had been a Japanese. I like fermented (therefore slightly acid) whale oil with my fish as well as ever I liked mixed vinegar and olive oil with a salad. But I still had two reservations against Eskimo practice; I did not eat rotten fish and I longed for salt with my meals.

There were several grades of decayed fish. The August catch had been protected by longs from animals but not from heat and was outright rotten. The September catch was mildly decayed. The October and later catches had been frozen immediately and were fresh. There was less of the August fish than of any other and, for that reason among the rest, it was a delicacy - eaten sometimes as a snack between meals, sometimes as a kind of dessert and always frozen, raw.

In midwinter it occurred to me to philosophize that in our own and foreign lands taste for a mild cheese is somewhat plebeian; it is at least a semi-truth that connoisseurs like their cheeses progressively stronger. The grading applies to meats, as in England where it is common among nobility and gentry to like game and pheasant so high that the average Midwestern American or even Englishman of a lower class, would call them rotten.

I knew of course that, while it is good form to eat decayed milk products and decayed game, it is very bad form to eat decayed fish. I knew also that the view of our populace that there are likely to be "ptomaines" in decaying fish and in the plebeian meats; but it struck me as an improbable extension of the class-consciousness that ptomaines would avoid the gentleman's food and attack that of a commoner.

These thoughts led to a summarizing query; If it is almost a mark of social distinction to be able to eat strong cheeses with a straight face and smelly birds with relish, why is it necessarily a low taste to be fond of decaying fish? On that basis of philosophy, though with several qualms, I tried the rotten fish one day, and if memory servers, like it better than my first taste of Camembert. During the next weeks I became fond of rotten fish.

Pickled Mammoths

Linking this back to the whole evolutionary fitness, palaeolithic hunter gatherer diet is this:

I came across something interesting about fermentation in the latest National Geographical. The cover story is about the discovery of a baby mammoth in Siberia. Although when found it was free of the ice it hadn’t decayed. On examination it was found that it had been “pickled” just through being in the water and thus preserved.

This was noticed by one of the researchers who noticed the pickled smell as he was doing the dissection. It reminded him of experiments that he had done to see whether primitive hunter gatherers could have preserved meat in this way. He submerged meat in a pool of water and found it was naturally pickled by the bacteria present. Hence his theory that hunters could have killed large prey (mammoths) and then preserved / fermented / pickled the meat for a long period after:

It is covered here:


Tikhonov knew that no one would be more excited by the find than Dan Fisher, an American colleague at the University of Michigan. Fisher is a soft-spoken, 59-year-old paleontologist with a bristly white beard and clear green eyes who has devoted much of the past 30 years to understanding the lives of Pleistocene mammoths and mastodons, combining fossil studies with some very hands-on experimental research.

Curious to know how Paleolithic hunters managed to store mammoth meat without spoilage, Fisher butchered a draft horse using stone tools he’d knapped himself, then cached the meat in a stock pond. Naturally preserved by microbes called lactobacilli in the water, the flesh emitted a faintly sour, pickled odour that put off scavengers even when it floated to the surface. To test its palatability, Fisher cut and ate steaks from the meat every two weeks from February until high summer, demonstrating that mammoth hunters might have stored their kills in the same way.

Also here

Based on previous experiments aimed at understanding how Paleolithic hunters stored meat from large animal kills, Fisher believes Lyuba was naturally pickled in lactic acid produced by microbes called lactobacilli. The pickling would have protected her body from decomposition, and the sour smell likely deterred scavengers.

So it is plausible that pickled meat - meat preserved through the same process of lacto fermentation that produced yoghurt or sauerkraut - is an ancient food......


What am I doing?


In the last week I have started eating some live yoghurt, kefir - when I can get it - and some genuine sauerkraut. I'll see how it goes.

9 comments:

Chavo said...

Thanks for a great post, Chris. I have often thought on these things. I've been playing with food using Sandor Katz Wild Fermentation- good book.

Marc said...

Chris,

Fantastic post.

I enjoy eating "Natto"....besides from enjoying it, it makes my body feel noticably "good".

My Romanian older friend makes me "Varsa" Basically romanian sauerkraut.

Green cabbage, water and some sea salt. 2 sprigs of dill.
It sits on my counter in glass jars and ferments and "spoils"
for about 4-5 days. Then I cover them and refrigerate. Same as the natto, it makes your body feel good. I look forward to reading more of Seth's blog.
Cheers,
Marc

Chris said...

Sounds great Marc.

thanks

JS said...

I just stumbled across this link today.. seems that somebody already does meat "spoiling"

http://www.rawpaleoforum.com/display-your-culinary-creations/high-meat-recipe-preparation-for-more-advanced-rafers/

Robert M. said...

I like the taste of sauerkraut but my throat has some sort of unpleasant reaction to it or the salt in it. I ate sauerkraut for a few weeks and suffered from dry, itchy throat. I went through and eliminated a whole bunch of stuff (coconut oil, whey, almonds, etc.) before I was able to figure out that sauerkraut was giving me problems.

I was reading a bit of Seth Robert's blog, some interesting thoughts there. He must be an economist though, because he has one idea and thinks its the answer to everything. It's sort of like de Vany and power law relationships.

JB said...

One of my absolutely favorite meals is homemade yogurt spooned on top of defrosted frozen blueberries and/or blackberries. The heat from the slightly hot berries and their juices sort of melt the yogurt making it as much a drink as a solid substance.

I only wish I could find a yogurt maker that would handle a full gallon of milk at a time.

One other thing... for people who enjoy cabbage sauerkraut, it is one of those foods that one almost gets a yearning for. One day you wake up... and you feel the need or urge to eat some. It is almost like some people having a sweet tooth that needs to be satisfied.

It tastes great with most meats, but a dollop of sour cream on top is also very good with sauerkraut.

JB

Robert M. said...

My favourite condiment for meat is probably beet and horseradish relish. Take a bunch of beets, boil them til they're soft, peel them, wash them again to remove any cross-contaminated dirt from the peeling, shred them and mix with a good amount of horseradish. Keeps in the refrigerator indefinitely.

Anonymous said...

Google Hakarl (Icelandic Rotten Shark) and Lutefisk (Norwegian aged buried fish treated with lye) for additional fermented delicacies!

ega278 said...

I myself found the "Wild Fermentation" book and found it very interesting. My wife likes kefir and keeps it going all the time on the counter, but I won't drink it. I like sauerkraut and make a quart of it every few weeks or so, but she won't eat it. I was surprised to find my kids each with a fork eating the sauerkraut right from the jar more than once though!

Oh, and you might want to keep that milk in the fridge. The reason being is that it's pasteurized, meaning that it's biologically dead. That leaves room for any kind of bacteria to get in there and multiply unrestrained. Raw milk is the ticket, we're lucky enough to have a farmer in the area who likes to do things the right way.