It’s packed with soy protein, fibre, B vitamins and antioxidant isoflavones mainly thanks to the fermentation process. Tempeh is full of nutrients that your body can easily absorb and it may help reduce oxidative stress, balance blood sugar, support cholesterol levels and bone health. Fermentation not only boosts vitamins, minerals, fiber, and isoflavones but also creates unique compounds that may have extra health benefits.

I crumble it like minced beef, but you can also grill it, stir-fry, or toss it into a salad. If you haven’t tried it yet, now’s the time!

What Is Tempeh

Originating in Central Java, tempeh begins with whole soybeans, soaked overnight and gently cooked. They’re then combined with a fermentation starter (Rhizopus), pressed into a flat block, and kept cozy in a warm place. Within just a few days, the culture weaves the beans together into a firm, nutty-flavored cake. That’s the magic of fermentation at work!

I’ve also seen beans such as lentils, chickpeas made into tempeh. I never tried it though but it’s good to know there are alternatives.

Nutritional and health benefits

• Protein: ~19 g protein
• Fibre ~ 6.6 g per 100g and according to the Monash University, a low FODMAP resource
• B-vitamins and minerals, especially zinc, iron and calcium
• Isoflavones, such as daidzein and genistein, are known for their antioxidant properties.

The beauty of fermentation goes beyond flavor: it breaks down anti-nutrients like phytic acid, increasing absorption of a lot of nutrients.

Did I mention it’s a high-quality plant-based protein source?

Tempeh stands apart from tofu because it uses the whole soybean, retaining more protein and fiber. The digestibility and amino acids are close to animal sources. The protein absorption is good thanks to the fermentation process. By comparison tofu starts with soy milk and a coagulant to form blocks. The nutrient profile is lower in protein, fibre, B vitamins and minerals. They complement each other very well, depending on the dish since tempeh has a nutty, earthy flavour and a firm texture from fermentation, while tofu is mild and soft.

Why is soy protein good for you?

Adding soy foods to your diet brings extra benefits:

• Heart health - protein, fiber and antioxidants can help inhibit cholesterol absorption and support bile acid production in the gut
• Stronger bones - fermentation improves calcium bioavailability
• Cancer risk reduction - due to the estrogen-like activity of antioxidants which is thought to provide anticancer effects
• Better gut health - thanks to the fibre and paraprobiotics (secondary metabolites of bacteria from fermented foods)

Is soy safe?

Looking at the current research, I can assure you soy foods are safe and don’t harm hormones in either men or women. Honestly, I was reluctant to recommend soy foods or consume them myself due to outdated animal studies. We now know that there’s extensive clinical trial data to show that:

• in men, there’s no effect on testosterone, estradiol or estrone levels and
• in women soy consumption can actually reduce the risk of breast cancer in pre-menopausal and post-menopausal women.

A Plant-Based Source of Vitamin K₂

Yes, I made vitamin K₂ a separate section!

Vitamin K₂—vital for guiding calcium into your bones and away from your arteries (a key to bone and heart health). Unfortunately, it's scarce in plant foods and in the diets of most of us, so let’s talk more about it.

Tempeh can produce some vitamin K₂ (especially menaquinone), less than natto, another type of fermented soybean food originating in Japan. Natto is one of the richest sources of vitamin K₂ thanks to the activity of the bacterium Bacillus subtilis.

K2 amounts in fermented foods can vary based on the type of fermentation and the microorganisms involved. This makes fermented foods an excellent source of K2, especially for those who do not consume animal products. Still, I recommend supplementation for most people. Check out my next blog post about vitamin D to understand more why that is.

Cooking Tempeh? So Many Ways

Wait, are there any probiotics in tempeh?

Since we usually cook tempeh, the lactic acid bacteria formed during the fermentation process and any other microorganisms are inactivated and become paraprobiotics. Paraprobiotics might still have health benefits.

Here are my favorite personal go-to ways of cooking tempeh:

• Marinated & cooked: Try tamari, garlic, maple syrup or honey, sesame oil—a quick crisp that's pure comfort. Then grill, fry or bake and add to lunch bowls or salads.
  
• Crumble it as a “mince” substitute with tomato sauce for tacos, chili, or pasta.
  
• Steam or bake, then toss into salads or grain bowls together with rice noodles, mint, peanuts (or almonds) and lime juice.
  
• Tempeh “bacon”: smoky, crispy—almost dangerously addictive.
  

Check out The Minimalist Baker or The Doctor’s Kitchen for more inspiration!

References & Further Reading

Boutas, Ioannis & Kontogeorgi, Adamantia & Dimitrakakis, Constantine & Kalantaridou, Sophia. (2022). Soy Isoflavones and Breast Cancer Risk: A Meta-analysis. In vivo (Athens, Greece). 36. 556-562. 10.21873/invivo.12737.

Hallis SP, Yanti Y, Suhartono MT, Ali S. Peptide Extracts from Tempeh Protect Against Photoaging via Down-regulating Matrix Metalloproteinase-3 Gene Expression. Jurnal Teknologi. 2020; 82.

Monash University about FODMAPS (Blog): https://www.monashfodmap.com/blog/low-fodmap-shopping-list

Reed KE, Camargo J, Hamilton-Reeves J, Kurzer M, Messina M. Neither soy nor isoflavone intake affects male reproductive hormones: An expanded and updated meta-analysis of clinical studies. Reprod Toxicol. 2021 Mar;100:60-67. doi: 10.1016/j.reprotox.2020.12.019. Epub 2020 Dec 28. PMID: 33383165.

Rizzo G. Soy-Based Tempeh as a Functional Food: Evidence for Human Health and Future Perspective. Front. Biosci. (Elite Ed) 2024, 16(1), 3. https://doi.org/10.31083/j.fbe1601003

Subali, D., Christos, R. E., Givianty, V. T., Ranti, A. V., Kartawidjajaputra, F., Antono, L., Dijaya, R., Taslim, N. A., Rizzo, G., & Nurkolis, F. (2023). Soy-Based Tempeh Rich in Paraprobiotics Properties as Functional Sports Food: More Than a Protein Source. Nutrients, 15(11), 2599. https://doi.org/10.3390/nu15112599

Sze Qi Teoh, Nyuk Ling Chin, Chun Wie Chong, Adiratna Mat Ripen, Syahmeer How, Joyce Jen Li Lim, A review on health benefits and processing of tempeh with outlines on its functional microbes, Future Foods, Volume 9, 2024, https://doi.org/10.1016/j.fufo.2024.100330.