Tempeh: Benefits of soy protein and isoflavones

10th Jan 2025

Made from fermented soybeans, tempeh is rich in protein, fibre and isoflavones, which may support cholesterol and bone health. Try it crumbled, grilled or stir-fried.

Key points

What is tempeh?

Tempeh starts with whole soybeans that are soaked overnight and cooked. They are then mixed with a fermentation starter (Rhizopus), shaped into a flat block and left in a warm spot. Over a couple of days, the starter binds the beans into a firm, nutty-tasting block. Fermentation magic!

Tempeh vs tofu

Both come from soybeans, but there are 3 key differences:

  1. Whole beans vs soy milk – Tempeh is made from whole soybeans, while tofu starts with soy milk and a coagulant to form blocks.
  2. Nutrients – Thanks to using whole beans and undergoing fermentation, tempeh is higher in protein, fibre, B vitamins and minerals. Fermentation also breaks down nutrients so they’re easier to absorb, lowers antinutrients and creates more beneficial compounds like isoflavones.
  3. Flavour and texture – Tempeh has a nutty, earthy flavour and a firm texture from fermentation, while tofu is mild and soft, soaking up flavours from sauces and spices. They complement each other perfectly, depending on the dish!

Source of

  • Protein – 19 g per 100g
  • Fibre – 6.6 g per 100g
  • B-vitamins and minerals, especially potassium, phosphorus and calcium
  • Isoflavones, such as daidzein and genistein, known for their antioxidant properties.

Quality protein? Soy is one of the best plant proteins, with digestibility and amino acids close to animal sources. Fermentation makes tempeh even better by lowering antinutrients and improving protein absorption.

Does tempeh have probiotics? Cooking inactivates them, but research shows heat-inactivated probiotics, called paraprobiotics, can still be beneficial.

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Is soy risky?

No, current research shows that soy foods are safe to enjoy and don’t harm hormones or raise cancer risk. Most concerns come from outdated animal studies. Plus, soy foods offer more than isoflavones. They are rich in protein, fibre, vitamins and minerals that support heart health and may reduce cancer risk.

  • In men – There’s a myth that soy “feminises” men, but extensive clinical trial data show no effect on testosterone or estrogen levels in men.
  • In women – Soy has been linked to a lower risk of breast cancer and can ease menopausal symptoms, making it a great addition to a balanced diet.

Health benefits of tempeh

Eating more soy foods is linked to several health benefits, including:

  • Heart health – Soy protein with isoflavones can help lower cholesterol and reduce the risk of heart disease, thanks to its low saturated fat and antioxidant effects.
  • Stronger bones – Studies suggest soy proteins rich in isoflavones may help slow bone loss.
  • Cancer risk reduction – Higher intake of soy foods is associated with lower risks of lung, gastric, and breast cancers.
  • Better gut health – Thanks to fibre and paraprobiotics.

Add tempeh to your meat dishes: We love pairing meat with tempeh for a balanced mix of flavours and nutrients. Research shows that getting just 3% more of your daily energy from plant proteins is linked to a 5% lower risk of dying from any cause.

How to choose in the shop

You’ll find it in larger supermarkets, health food stores and online.

  1. Check the ingredients: Look for plain tempeh with minimal ingredients – ideally just soybeans and a starter culture (Rhizopus). Skip options with fillers, preservatives or artificial flavours.
  2. Pre-marinated vs plain: Plain tempeh gives you more control over flavour and seasoning. Pre-marinated options can be convenient but often come with added sugar, salt, or artificial ingredients – check the label.
  3. Know the source: If you can, look for brands or local producers known for quality fermentation. Good tempeh relies on a strong starter culture with plenty of Rhizopus spores for proper fermentation.

If you’re not a fan (yet)

  • Pair with flavours you like – Try different seasonings, sauces and pairings to modify its flavour and cook it the way you like.
  • Nail the texture – Texture can make or break your tempeh experience. It’s all about finding the style you enjoy most.
  • Give it multiple chances! Not all tempeh tastes the same. Different brands, recipes and cooking methods can make a huge difference. If one didn’t do it for you, don’t give up – there’s probably a version out there you’ll love.

3 ways to enjoy

  1. Go-to marinade – Marinate with sesame oil, tamari, maple syrup or honey and paprika. Then grill, fry or bake and add to lunch bowls or salads.
  2. Noodle salad – Bake until crispy and toss with rice noodles, mint, peanuts and peanut-lime dressing.
  3. Bolognese – Crumble or grate and add to your favourite tomato sauce.
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