Category: fermented food

Natto Shopping

Seth Roberts9 Comments

After re-reading this post, written before my current fermented-food craze, I decided to see if I could buy natto (fermented soybeans) in Berkeley. At Whole Foods, they didn’t know what it was. Nor did they sell it. At Berkeley Bowl, which Saveur magazine recently seemed to say was the best food market in America, they told me it was in Aisle 3. I looked and looked and couldn’t find it. Okay, frozen natto is in Aisle 7, I was told. There was a surprisingly large selection, maybe 10 choices. Frozen natto comes in one-serving plastic containers bundled into packages of two or three that look like this:

That’s a two-container bundle. One serving is about $1.
Introduction to natto.

Hanging Birds

Seth Roberts9 Comments

In the comments, Patrik links to a fascinating post about “hanging game birds” — that is, hanging them at low temperatures (such as 50 degrees) for several days to improve their flavor. I especially liked this quote from Brillat-Savarin:

The peak is reached when the pheasant begins to decompose; its aroma develops, and mixes with an oil which in order to form must undergo a certain amount of fermentation.

Yet another example of more bacteria, better flavor. I can’t find my copy of Brillat-Savarin but in Harold McGee’s On Food and Cooking I found this (p. 144):

Despite the contribution that aging can make to meat quality, the modern meat industry generally avoids it, since it means tying up its assets in cold storage and losing about 20% of the meat’s weight to evaporation and laborious trimming of the dried, rancid, sometimes moldy surface.

Okay, I am taking those short ribs I bought today out of the freezer. If people knew that well-aged beef is healthier, as I believe, this meat-industry practice might change. There should be a recommended daily allowance of bacteria. A few billion, perhaps? Bacteria count would be included in the nutrition label. Because the numbers would be so large, everyone would learn scientific notation.

What Did Eskimos Eat?

Seth Roberts13 Comments

In the early 1900s, the anthropologist/explorer Vilhjalmur Stefansson, after living with Eskimos for a long time, returned to tell Americans what he had learned about nutrition. Eskimos ate meat almost exclusively, he said, which contradicted the usual emphasis, then as now, on diversity and fruits and vegetables. Yet Eskimos were healthy. Eskimo diet became even more fascinating when it was realized they had very low rates of heart disease — much lower than Danes, for example. In the 1970s, two Danish doctors, Bang and Dyerberg, found that Eskimos had large amounts of omega-3 fats in their blood, much more than Danes; that was the beginning of the current interest in omega-3 and the idea that fish and fish oil are “heart-healthy”.

As I pointed out earlier, discussions of the Eskimo diet have ignored the fermented food they ate. Here’s what Stefansson said in 1935:

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. . . .

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. . . .

[At first, Stefansson didn’t want to eat decayed fish.] While it is good form [in America] to eat decayed milk products and decayed game [well, well], it is very bad form to eat decayed fish. . . . 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 serves, liked it better than my first taste of Camembert. During the next weeks I became fond of rotten fish.

So Eskimos ate fermented whale oil and a lot of rotten fish. (“A lot” because if they didn’t eat a lot of it, Steffanson wouldn’t have felt pressure to eat it.) I had no idea that Americans used to eat decayed game.

Bacteria and Learning?

Seth Roberts2 Comments

Do bacteria-laden foods improve learning? A recent study:

The ability of dietary manipulation to influence learning and behavior is well recognized and almost exclusively interpreted as direct effects of dietary constituents on the central nervous system. The role of dietary modification on gut bacterial populations and the possibility of such microbial population shifts related to learning and behavior is poorly understood. The purpose of this study was to examine whether shifts in bacterial diversity due to dietary manipulation could be correlated with changes in memory and learning. Five week old male CF1 mice were randomly assigned to receive standard rodent chow (PP diet) or chow containing 50% [raw] lean ground beef (BD diet) for 3 months. As a measure of memory and learning, both groups were trained and tested on a hole-board open field apparatus. Following behavioral testing, all mice were sacrificed and colonic
stool samples collected and analyzed by automated rRNA intergenic spacer analysis (ARISA) and bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP) approach for microbial diversity. Results demonstrated significantly higher bacterial diversity in the beef supplemented diet group according to ARISA and bTEFAP. Compared to the PP diet, the BD diet fed mice displayed improved working (P = 0.0008) and reference memory (P < 0.0001). The BD diet fed animals also displayed slower speed (P < 0.0001) in seeking food as well as reduced anxiety level in the first day of testing (P = 0.0004). In conclusion, we observed a correlation between dietary induced shifts in bacteria diversity and animal behavior that may indicate a role for gut bacterial diversity in memory and learning.

Previous studies had found that changes in diet changed behavior. This article says that changes in diet can produce changes in bacterial diversity and these bacterial changes might have caused the behavior changes.

Eventually I will stop eating lots of fermented food and see what happens. Perhaps my arithmetic scores will get worse.

Where Does Umami Come From?

Seth Roberts1 Comment

As previously blogged, the evolutionary reason we like umami taste may be so that we’ll eat more bacteria-laden food. This makes sense only if bacteria-laden food would have been the main source of umami. Nowadays, you can get umami from MSG. What about before MSG?

The Umami Information Center sent me a free booklet called Umami The World — a better title than Umami: An Introduction. Umami taste is mainly supplied by glutamic acid, a protein building block. My assumption was that glutamic acid is usually a protein breakdown product. Bacteria feed on protein, leaving a pile of bricks — glutamic acid among them. Was this correct? Or could you get umami taste without bacteria?

You can, but in most cases you don’t. In Japanese cooking, a potent source of umami is konbu, a type of seaweed. Perhaps because konbu produces so much umami and so little else that umami was discovered by a Japanese scientist. Umami flavorings are used in many other cuisines but the source is usually fermented food. In many Asian countries, umami comes from fermented fish sauce and fermented bean products (e.g., miso, soy sauce). In Chinese cooking, umami comes from a condiment called jiang, which is made from fermented grain, meat, or fish. In Western cuisines, cured pork is often used as a flavoring agent. “The curing process liberates more of the glutamic acid content of the meat.” Curing takes place at room temperature, which means bacteria grow. “Much of the food of ancient Rome was routinely seasoned with a sauce [that] was made from salted fish, fermented and strained. . . The polar Eskimo people traditionally fermented a small portion of their harvest of fish.” Tomatoes and shitake mushrooms are non-fermented sources of umami.

A telling comment in the book is that umami usually comes from sauces (e.g., fish sauce) or liquids (e.g., dashi, bouillion). Cooks use sauces and liquids to add what is missing. The presence of umami in so many sauces — as if sauces have been devised or selected to be high in umami — suggests that ordinary foods don’t have much umami. A table of glutamate concentration says that parmesan cheese has 1700 mg/100 g whereas several vegetables — tomatoes (246 mg/100 g), green pea (106), onion (51), spinach (48), potato (10) — and meats — beef (10), chicken (22), pork (9) — have much less.

The breakdown process I imagined is spelled out: “During the ripening of cheese, proteins are broken down progressively into smaller polypeptides and individual amino acids. Large increases in free amino acid content also occur during the curing of ham.” Surely the same will be true during room temperature aging of any protein source. Beef is routinely aged at room temperature for about a week to give it a “meaty” flavor (not from the umami book but from here).

Bees and Fermented Foods

Seth Roberts5 Comments

I became interested in fermented foods less than two months ago but I’m sure I’ll be eating plenty of them for the rest of my life. The benefits have been very clear and — not that it matters — the intellectual case is strong. Being new to it, I have wondered how my ideas and habits might evolve.

I got a glimpse of a possible future from a comment on this blog by Heidi. She linked to a page about kombucha and probiotics and bee-keeping and later sent me a link to a discussion of using probiotics to keep bees healthy. A discussant named Tim Hall said this:

I once scratched open my index finger, and somehow caught an MRSA [Methicillin-resistant Staphylococcus aureus] infection so bad I was in the hospital for a week. This incident completely changed my perspective on chemical culture. Now not a day goes by that I don’t ingest some form of live cultured food…most of it I culture myself.

I make kefir on a daily basis. Kombucha I have not tried since I avoid caffeine. I also make my own sauerkraut, kimchi, koji, miso and koji pickles (and of course mead).

Hmm. I have never made kefir, but it’s not hard to make. I hadn’t even heard of koji, which is a kind of fermented rice.

Umami Burger

Seth Roberts4 Comments

A new restaurant with the excellent name Umami Burger has just opened in Los Angeles. According to The Foodinista, the food is as good as the name:

An attractive space with an attractive clientele. The tightly edited menu consists of 10 burgers, and a few sides including fries and a market salad. But, we’re told at 12:45 pm on a Tuesday afternoon, they’ve run out of buns. . . . amazing homemade ketchup . . . The beef patties on all of the above, really flavorful and just plain GOOD. I don’t know how they can make such a great burger and charge so little. . . . I’m telling you, the burgers are great.

Review by Jonathan Gold.
Thanks to Tucker Max.

Oral Health, Heart Disease, and Fermented Foods

Seth Roberts6 Comments

From the abstract of a 2007 paper about oral health and heart disease:

The high prevalence of cardiovascular diseases (CVD) and infections of the mouth has led to the hypothesis that these disease entities [are] connected. Oral biofilms contain numerous micro-organisms with more than 700 identified species. . . . These micro-organisms cause dental caries and periodontal disease of which the majority of humans suffer during their life. Oral bacteria are presumed to gain access to the blood circulation and are postulated to trigger systemic reactions by up-regulating a variety of cytokines and inflammatory mediators. Infection and inflammation play a role also in atherogenesis. Furthermore, traces of oral micro-organisms, such as the gram-negative anaerobic bacterium Porphyromonas gingivalis, have been detected in atheroma plaques. This bacterium seems to be potentially atherogenic in animal models. Epidemiologic data have shown a statistical association between periodontal disease and coronary heart disease and stroke. In a meta-analysis, the odds ratio increase for CVD in persons with periodontal disease was almost 20%. Poor oral health also seems to be associated with all-cause mortality.

Emphasis added. As I blogged earlier, during my last trip to the dentist I was told my gums were in great shape, better than the previous visit — and the only intentional change since the previous visit was a huge increase (a factor of 50?) in how much fermented food I eat. So perhaps fermented foods improve oral health. A reason to suspect that fermented foods reduce heart disease is that Eskimos, with very low rates of heart disease, eat lots of fermented food. If both these ideas are true — fermented foods improve gum health and reduce heart disease — it would explain the observed correlation between gum disease and heart disease.

A vast number of people believe that sugar and refined flour are bad for us. In large amounts, sure, because they cause so much dysregulation (e.g., high blood sugar) and in ditto foods cause obesity. But what about average amounts? Here I’m not so sure. The shift to a diet high in sugar and refined flours has usually happened at the same time as a shift away from traditional diets. In other words, the increase in sugar and flour wasn’t the only change. I suspect there was usually a great reduction in fermented foods at the same time. Maybe the reduction in fermented foods caused the trouble rather than the increase in sugar and flour. The reduction in fermented foods is almost always ignored – for example, by Weston Price and John Yudkin (author of Sweet and Dangerous).

Probiotics and oral health. An experiment about probiotics and oral health.

Antibiotic Foods?

Seth Roberts8 Comments

Just as there are probiotic foods — that encourage digestive bacteria — perhaps there are antibiotic foods that kill them off. Stacy Ashworth writes:

The flip side of the good-bacteria-stimulates-the-immune-system theory must be that bacteria-killing-foods-weaken-the-immune-system theory. Could this be why I come down with a cold within a day or so of indulging junk food cravings, food that is chock full of bacteria-killing preservatives? . . . I’m also looking at food preservatives in a new light: if they are added to food to kill bacteria to keep the food fresher, then I suppose it stands to reason that they are also going to kill off some of the immune-system enhancing bacteria in my body.

Do some popular foods kill a significant amount of internal bacteria? I don’t know.

I’m sure you need to eat lots of bacteria to stimulate your immune system; the ones already in your body are not recognized as new. New bacteria must come from outside. Then the problem with preservatives is not that they kill bacteria in our bodies but that they have made the preserved food unusually low in bacteria.

“I Started Eating More Fermented Food…” (continued)

Seth Roberts4 Comments

Previously: Tucker Max found that drinking two bottles per day of kombucha for a a week had several easy-to-notice unexpected benefits.

I have some comments:

1. The best thing about these observations is how simple the change is: two bottles/day of a readily available kombucha brand. Very easy to duplicate — let’s not worry about matching Tucker’s weight, etc.

2. The speed with which the changes were noticed (within a week) makes the whole thing even easier to try to duplicate.

3. Kombucha was not one of the fermented foods from which I drew my conclusions about fermented foods. Bacteria are so varied that the notion that all fermentation bacteria have somehow the same effect isn’t easy to believe. But since the prediction about fermented foods (they are highly beneficial) turned out to be true maybe there is something to this.

4. 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.

5. I used to make kombucha. I’m going to start again.