Tofu and Tempeh: Two Soy Foods Worth Getting to Know

How they compare for health, how to cook them, and what the evidence says about libido

For years, I was told that tofu was bad for a man's libido. It is the kind of warning that sticks in your mind, especially when you are trying to eat well.

But does the evidence support it? And how does tofu compare with its firmer, fermented cousin, tempeh?

Both can earn a place in a healthy kitchen. Choosing between them depends on the dish, the product, and the nutrients you want to include.

What is the difference?

Tofu is made by coagulating soy milk and forming the curds into blocks. It ranges from delicate silken tofu to firm varieties suitable for frying and baking.

Tempeh is made by fermenting cooked soybeans with a starter culture, traditionally a Rhizopus mould. The beans bind into a compact cake. It has a chewy texture and a nutty, earthy flavour.[1]

Feature	Tofu	Soybean tempeh
Main ingredient	Soy milk	Whole soybeans
Fermented?	Ordinary fresh tofu is not fermented	Yes
Texture	Silky, soft, or firm	Firm and chewy
Flavour	Mild; takes on sauces and seasonings	Nutty and more pronounced
Protein	Varies considerably with firmness and brand	Usually concentrated; some high-protein tofu can match it
Fibre	Usually less	Usually more, because the beans remain
Calcium	Can be substantial when made with calcium sulfate	Contains some, but is not automatically a high-calcium food
Useful dishes	Soups, scrambles, curries, crispy cubes, sauces	Stir-fries, sandwiches, skewers, crumbles

Check the label rather than assuming every block is nutritionally identical. Tempeh containing grains and flavoured products can differ from plain soybean tempeh.[1]

Which is healthier?

Both supply complete soy protein, meaning they contain all nine essential amino acids. That makes them useful ingredients when building meals that support muscle maintenance as we age.[2]

Tempeh is a good choice when you want a firm texture, fibre, and a concentrated protein source. Tofu offers more texture options, and calcium-set tofu can help with calcium intake. Look for “calcium sulfate” in the ingredients, then check the calcium amount on the label.[3]

Soy protein may modestly lower cholesterol when it replaces other proteins. That does not mean either food is a treatment for heart disease.[4] Preparation matters too: a heavily deep-fried version with a salty sauce is a different meal from lightly browned soy served with vegetables.

Fermentation can alter digestibility, but it does not make tempeh universally superior.[2] Nor should cooked or pasteurised tempeh automatically be described as a source of live probiotics.

Neither plain tofu nor ordinary tempeh should be relied on to meet vitamin B12 needs. People eating a fully plant-based diet need a dependable B12 source, such as appropriate fortified foods or a supplement.[5]

Does tofu reduce libido?

The idea often comes from soy's isoflavones, compounds sometimes called phytoestrogens. They can interact with estrogen receptors, but they are not equivalent to the body's estrogen.[2]

A 2021 meta-analysis combined 41 clinical studies and found no significant effect of soy protein or isoflavone intake on men's total testosterone, free testosterone, or the estrogen measures studied.[6]

That is reassuring, but testosterone and libido are not the same thing. The review measured hormones, rather than directly establishing how every man's sexual desire responds.

The useful conclusion is that the claim “tofu lowers testosterone and therefore damages libido” is not supported by that clinical evidence. There is no established reason to avoid normal servings of tofu or tempeh on this basis. Neither should be promoted as a libido booster, either.

If sexual desire or erections change persistently, it is better to discuss the change with a clinician than to assume tofu is responsible.

How to prepare tofu

Crispy garlic-and-onion tofu

For two servings, use:

300 g firm tofu
1 tablespoon rice flour, or 2 teaspoons arrowroot
1 teaspoon garlic powder
1 teaspoon onion powder
2 teaspoons olive oil
Black pepper and a little salt, if wanted

Drain the tofu. If it is water-packed and quite wet, press gently for 15–20 minutes. Pat dry.
Cut into approximately 2 cm cubes.
Toss with the oil, then the flour or arrowroot and seasonings. Use a light coating.
Spread in one layer. Bake in a preheated conventional oven at 200°C for approximately 25–30 minutes, turning halfway, until golden.
For a halogen oven, start around 180°C and check after 12–15 minutes. Turn and continue until golden; timing depends on the oven and rack position.
Add a wet sauce after cooking to preserve the crust.

Rice flour gives a light crust; arrowroot is another coating option. Neither is necessary for nutrition—the coating is for texture.

For a pan version, brown the cubes in a lightly oiled pan over medium heat, turning as the surfaces colour. Avoid crowding the pan.

Other easy uses

Crumble firm tofu into a scramble with turmeric, mushrooms, onions, and greens. Add soft tofu gently to soup. Blend silken tofu with lemon, herbs, and mustard for a creamy dressing.

Press firm tofu when you want a dry surface. Do not press delicate silken tofu.

How to prepare tempeh

Ginger-and-lime tempeh

For two servings, use:

250 g plain soybean tempeh
1 tablespoon reduced-salt soy sauce or tamari
1 tablespoon lime juice
1 tablespoon water
1 teaspoon grated ginger
1 crushed garlic clove
2 teaspoons olive oil

Cut the tempeh into slices about 1 cm thick.
Optionally steam for 10 minutes to soften its flavour, then cool briefly and pat dry.
Mix the marinade ingredients and coat the slices. Leave for 20–30 minutes in the refrigerator.
Brown in a pan over medium heat, approximately 3–5 minutes per side, until hot through. Follow any package cooking instructions.
Alternatively, bake at 190°C for approximately 20–25 minutes, turning halfway and checking that it is thoroughly heated.

For a halogen oven, start at 180°C, check after 10–12 minutes, and continue as needed. Keep garlic from scorching.

Serve with brown rice and vegetables, tuck into a sandwich, or crumble into a tomato-and-mushroom sauce. No added sugar is needed in the marinade.

Buying and storing

Choose products with a clear use-by date and follow their refrigeration, opening, and cooking instructions. Keep opened products chilled promptly; Thailand's kitchen heat is no friend to forgotten leftovers.

Avoid soy products if you have a soy allergy.[4] If you take levothyroxine, ask your pharmacist how to separate it from soy meals, because soy can interfere with its absorption.[2]

A place for both

Tofu gives a meal versatility; tempeh gives it bite. Use calcium-set tofu when that suits your nutritional needs, and tempeh when you want whole-bean texture and fibre.

There is room for both—and the testosterone evidence gives men a good reason to reconsider the old warning about tofu.

Sources

Cleveland Clinic: Nutrition and Health Benefits of Tempeh
Harvard Nutrition Source: Straight Talk About Soy
USDA MyPlate: Dairy Group
NCCIH: Soy: Usefulness and Safety
NIH Office of Dietary Supplements: Vitamin B12
Reed et al., 2021: Neither soy nor isoflavone intake affects male reproductive hormones

Prepared for HealthyRetired.com. General information, with cooking times offered as starting points rather than guarantees for every appliance.