Tempeh is a fermented soy product with a savory flavor. Tempeh is easy to digest and, in contrast to tofu, provides significantly more vital substances. Tempeh tastes best when fried in a pan.
Tempeh tastes hearty and can be prepared in many ways
Tempeh is a fermented soy product with a high protein content (nearly 20 g per 100 g). Until a few years ago, it was still quite unknown in our latitudes. In the meantime, however, tempeh can be found on more and more refrigerated shelves.
Thanks to its nutty-mushroom-like taste and firm consistency, it is used in a variety of food preparations. Similar to tofu, tempeh is offered in blocks or slices. It can be roasted, fried, grilled, or baked. Actually, there is hardly a preparation that would not be suitable for tempeh. He will be happy with z. B. Tamari and fresh spices marinated and then processed. Tempeh is also commercially available smoked or pre-fried.
Tempeh goes perfectly with vegetable and rice dishes but also tastes great in soups, stews, salads, sauces, or casseroles.
While tofu originally comes from Chinese cuisine, tempeh comes from Indonesia. It has its origins in Java, one of the main Indonesian islands, where tempeh still makes a significant contribution to meeting the protein needs of the population.
Just like tofu, the basis for making tempeh is the soybean. However, while tofu is made from soy milk (by adding a coagulant (e.g. nigari) to it), tempeh requires whole soybeans. These are washed, soaked for 24 hours, boiled for a few minutes, and then soaked again for 24 hours.
You can then easily remove the shells of the beans. Now the soybeans are sterilized and finally treated with the so-called Rhizopus oligosporus, a noble mold that transforms the beans into tempeh in a two-day fermentation process at 30°C.
During this time, a dense network of white fungal filaments develops around the soybeans, which now hold the beans firmly together. It is also helpful to add vinegar, which lowers the pH value and thus creates a pleasant environment for the Rhizopus fungus. This type of production can be compared to the production of Camembert.
Tempeh is gluten-free
Since tempeh is a soy product that consists exclusively of soybeans, water, vinegar, and noble mold, it is inherently gluten-free. Gluten is a protein found in some grains such as wheat, rye, spelled, or barley and some people cannot tolerate it.
The well-known gluten intolerance recognized by conventional medicine is called celiac disease. In particular, it leads to digestive problems (but many other health problems are also possible).
Another form of gluten intolerance is the so-called gluten sensitivity independent of celiac disease. The evidence for celiac disease is negative here so many conventional doctors do not believe in its existence – but this does not change the fact that those affected are much better off on a gluten-free diet, which may also include tempeh and tofu, than before.
Tempeh for histamine intolerance
Since tempeh is a fermented food and therefore has a high histamine content, it is not suitable for those with histamine intolerance.
The vitamins and minerals in tempeh and tofu
Our vitamin and mineral chart lists the vitamins and minerals per 100 grams of tempeh (compared to tofu). Only vital substances that makeup at least 1.5 percent of the daily requirement are listed.
In brackets, you will find the value that indicates the percentage of the respective amount of vital substances that can cover the daily requirement. RDA stands for Recommended Daily Allowance.
The vital substances in which there are enormous differences between tempeh and tofu are marked in color. The values for tempeh here are at least twice as high as for tofu. Tempeh often contains many times the tofu values.
For example, tempeh provides 32 times more vitamin B2 than tofu. Tempeh also contains more than twice the amount of vitamin K. The same applies to iron and manganese. Tempeh also provides 4.5 times more magnesium than tofu and 17 times more zinc.
Is Tempeh a Good Source of Vitamin B12?
Tempeh is often cited as a good source of vitamin B12. Vitamin B12 is the vitamin that is particularly found in foods of animal origin, which is why it is recommended to supplement it in vegan diets.
Since vitamin B12 is formed by microorganisms, fermented foods are often discussed as having the appropriate vitamin B12 content. However, it is often unclear whether the vitamin B12 it contains is actually bioavailable, i.e. usable, which is very often not the case. One then speaks of so-called analogs – forms of vitamin B12 that cannot be used by humans.
According to official values in Germany (Federal Food Code), tempeh contains 1 µg of vitamin B12, which is at least a third of the daily requirement (3 µg). In the US databases, however, it is only 0.1 µg of vitamin B12. In Thailand, it looks completely different again. Analyzes of 10 different types of tempeh showed average values of around 1.9 µg of vitamin B12.
It is clear that soybeans do not contain any vitamin B12, so the vitamin has to form during fermentation. However, as is well known, the noble fungus does not ensure the production of vitamin B12.
This was confirmed and supplemented by a German team of scientists in a study, in the course of which they determined that, in addition to Klebsiella pneumoniae, the bacterium Citrobacter freundii can also provide vitamin B12 enrichment.
Since the formation of vitamin B12 during tempeh production is a kind of gamble or cannot even take place in hygienic production, we would not call tempeh a reliable supplier of vitamin B12 – as we already did in our article about vegan vitamins -B12 sources noted.
However, research is currently being carried out into ways of increasing the vitamin B12 content in tempeh. In a current study project, Prof. Dr. Eddy J. Smid from the University of Wageningen in the Netherlands is currently working on lupine tempeh (not soy tempeh) to see whether the concentration of certain bacteria (Propionibacterium freudenreichii) could increase the vitamin B12 content. “A significant increase in vitamin B12 (up to 0.97 µg/100 g) was achieved,” writes the scientist about his results to date. However, there is not yet such B12-rich tempeh on the market.
The high content of isoflavones
Compared to tofu and other soy products, tempeh has a higher isoflavone content, as shown in the table below. Isoflavones are secondary plant substances with e.g. antioxidant and estrogen-like effects. Soy products are recommended for menopausal symptoms due to their isoflavone content, which can reduce hot flashes. Under certain circumstances, isoflavone-containing foods can also be helpful for hormone-dependent types of cancer (breast cancer and prostate cancer) or for their prevention.
Anti-nutritional substances: lectins, phytic acid & Co.
Tempeh is therefore food that contains higher amounts of many desirable substances – vitamins, minerals, and phytochemicals – than many other foods. What about those substances that you would rather not consume in such large quantities?
When it comes to soy, the so-called anti-nutritive are often mentioned in this context. These are, for example, lectins, substances that are said to clot the blood and can lead to blood clots. However, as we explained in our main soy article, processing soybeans into tofu or soymilk removes most of the lectins. Another step is added to the production of tempeh – fermentation. This ensures that ultimately there are no more lectins to be found in the tempeh.
Phytic acid and oxalic acid are also antinutritives. Both are significantly reduced in quantity during fermentation. It has been known since 1985 that the fermentation and subsequent storage plus heating of the tempeh during frying reduces the phytic acid content to 10 percent of the original amount of phytic acid. It’s also important to note that phytic acid isn’t all bad. On the contrary. There have long been indications (see here under 12.) that it in no way inhibits the absorption of minerals to any noticeable extent, and even has a bone-strengthening, anti-cancer, and antioxidant effect.
Tempeh made from chickpeas, lupins, and peanuts
By the way, tempeh is not only made from soybeans. It is also made from chickpeas, lupins, peanuts, or a combination of these legumes. So if you don’t like or tolerate soy products, you can still enjoy tempeh.