Is Firm Tofu Lower in FODMAPs than Soft?

December 30, 2025 •

3 min read

According to Monash University, the research leaders in FODMAP testing, firm tofu is significantly lower in FODMAPs than silken (soft) tofu. The key difference lies in the processing method, where firmer varieties have more of the water-soluble FODMAPs pressed out during manufacturing.

Quick Summary

Processing methods heavily influence a food's FODMAP levels. Firm tofu undergoes pressing, which removes water and water-soluble FODMAPs like GOS and fructans. Soft, or silken, tofu retains this water, resulting in higher FODMAP content and smaller allowable servings for those on a low FODMAP diet.

Key Points

Processing Matters: Firm tofu is pressed to remove water, which also removes the water-soluble FODMAPs like GOS and fructans.
Lower FODMAP Content: Due to the pressing process, firm tofu has a much lower overall FODMAP load compared to silken tofu.
Larger Serving Sizes: Monash University confirms larger, safe serving sizes for firm tofu (up to 170g) versus the much smaller portions recommended for silken tofu (around 39g).
Check for Added Ingredients: Always read labels, as pre-seasoned or marinated tofu may contain hidden high FODMAP ingredients like garlic and onion powder.
Press Tofu at Home: For an even lower FODMAP content and better texture, press firm or extra-firm tofu at home to remove additional moisture.
Versatile Protein Source: Firm tofu is a safe, flexible, and delicious plant-based protein option for those adhering to a low FODMAP diet.

Understanding FODMAPs and Tofu

FODMAPs are a group of short-chain carbohydrates that can cause digestive distress for individuals with Irritable Bowel Syndrome (IBS) and other sensitivities. The FODMAP acronym stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. Soybeans, the primary ingredient in tofu, naturally contain oligosaccharides (specifically GOS and fructans), which are high FODMAP.

However, the processing of soy-based products has a profound effect on their final FODMAP content. This is because GOS and fructans are water-soluble. This critical detail explains why firm tofu is lower in FODMAPs than its softer counterparts.

The Role of Processing in Tofu's FODMAP Content

During the production of tofu, soybeans are processed into soy milk, which is then coagulated and pressed into blocks. The firmness of the tofu depends on how much water is pressed out of the block. Firmer tofu, such as extra-firm and firm, has a significant amount of water removed. This pressing and draining process effectively removes many of the water-soluble oligosaccharides, resulting in a lower FODMAP food.

In contrast, silken or soft tofu is largely unpressed, retaining most of its moisture and, consequently, its water-soluble FODMAPs. This is why it has a much higher FODMAP content per serving compared to firm tofu.

Comparison: Firm vs. Soft Tofu


Feature	Firm Tofu	Silken (Soft) Tofu
Water Content	Lower; pressed out during manufacturing.	Higher; largely unpressed, retains moisture.
FODMAP Level	Lower, as water-soluble GOS and fructans are drained away.	Higher, as water-soluble GOS and fructans remain in the block.
Recommended Serving (Monash)	Generous low FODMAP servings (e.g., 170g).	Small low FODMAP servings (e.g., 39g).
Texture	Dense and hearty; holds its shape well when cooked.	Delicate and custard-like; crumbles or blends easily.
Best Uses	Stir-frying, baking, grilling, scrambling, or adding to salads.	Smoothies, soups, sauces, dressings, and desserts.

Practical Implications for a Low FODMAP Diet

For those managing IBS, understanding this distinction is crucial for meal planning. While firm tofu is a versatile, protein-rich staple, silken tofu must be used in very small quantities to remain within the low FODMAP threshold. This makes firm tofu a much more convenient and flexible protein source during the elimination phase of the diet. It's always best to rely on up-to-date guidance from resources like the Monash University FODMAP app for the most accurate and current serving sizes for all types of tofu.

Tips for Preparing Firm Tofu

To maximize the flavor and texture of firm tofu while on a low FODMAP diet, consider these preparation tips:

Press It Further: Even though it's already pressed, you can remove even more moisture from firm tofu by wrapping it in a towel and placing a heavy object on top for 30 minutes. This creates a denser, chewier texture and can help with absorbing marinades.
Flavor with Low FODMAP Ingredients: Since most seasoned or pre-marinated tofus contain high FODMAP ingredients like garlic and onion powder, it's best to season it yourself. Use spices like turmeric, paprika, and herbs, along with low FODMAP sauces like tamari or specific low FODMAP ketchup.
Crisp It Up: For a satisfying texture, bake or pan-fry your firm tofu until golden brown and crispy. This can be done by coating it in a little cornstarch and oil before cooking.

Conclusion

Yes, firm tofu is significantly lower in FODMAPs than soft tofu. This is due to the manufacturing process, which removes the water-soluble GOS and fructans present in soybeans during pressing. For anyone following a low FODMAP diet, firm or extra-firm tofu represents a safe and versatile plant-based protein source. In contrast, silken tofu must be consumed in much smaller, controlled portions to avoid digestive issues. By choosing the right type of tofu and preparing it with low FODMAP seasonings, individuals can enjoy this nutrient-dense food without triggering symptoms.

Where to Find More Information

For the most precise and up-to-date FODMAP information, consult the Monash University FODMAP app or website. Reliable low FODMAP recipes and guidance can also be found from dietitians specializing in digestive health, such as those at Fresh Approach Nutrition.

Frequently Asked Questions

Soybeans are high in FODMAPs (specifically GOS and fructans), but because these carbohydrates are water-soluble, the manufacturing process for firm tofu, which presses and drains the water, removes most of the FODMAPs.

Yes, but only in very small, controlled portions. Monash University recommends a serving of around 39g, which is a much smaller amount than the recommended serving size for firm tofu.

While firm tofu is already pressed during manufacturing, pressing it further at home can improve its texture and allow it to absorb marinades better. It may also remove trace amounts of any remaining FODMAPs.

Look for plain firm, extra-firm, or fermented tofu. Avoid silken and soft tofu. Check the ingredient list for any added high FODMAP ingredients like onion or garlic powder.

The main difference is the amount of water removed. Firm tofu is highly pressed, draining away water and FODMAPs, while silken tofu is not pressed, retaining its high water and FODMAP content.

Freezing tofu changes its texture, making it chewier and more sponge-like, which helps in pressing out more water during the thawing process. This can further concentrate nutrients and may help reduce FODMAPs, though processing is the primary determinant.

Fermentation processes can reduce FODMAP content in many foods, and this is generally true for fermented soy products like tempeh and potentially fermented tofu, as bacteria feed on the carbohydrates. However, confirming the specific FODMAP content of any fermented tofu requires testing.