Nutrition Diet: How do you reduce sodium in soup?

October 18, 2025 •

5 min read

Excessive dietary sodium intake is a known risk factor for conditions like hypertension, cardiovascular, and renal diseases. To prioritize your health, learning how to reduce sodium in soup is a simple and effective strategy for home cooks and nutrition-conscious individuals alike.

Quick Summary

Several methods can fix an overly salty soup or prevent excess sodium in the first place. Strategies include adding unsalted ingredients to dilute the flavor, incorporating acidic components for balance, and prioritizing homemade stock and fresh herbs for robust taste without relying on salt.

Key Points

Dilute and Conquer: Add unsalted water, broth, or dairy to an overly salty soup to decrease the salt concentration per serving.
Balance with Acid: Use a splash of lemon juice, lime juice, or vinegar to cut through and counteract the salty taste, which is a quick fix for minor over-seasoning.
Bulk Up with Starches: Incorporate unsalted potatoes, rice, or pasta to absorb excess salt and increase the overall volume of your soup.
Prioritize Low-Sodium Ingredients: Prevent high sodium by starting with no-salt-added broths and rinsing canned goods like beans and vegetables thoroughly.
Flavor with Aromatics and Herbs: Build flavor from the ground up by sautéing onions, garlic, and celery, and using fresh herbs and spices instead of relying on salt.
Taste Throughout the Process: Season your soup incrementally and taste as you go, remembering that flavor concentrates as the liquid reduces during cooking.

Immediate Fixes for an Overly Salty Soup

Even the most experienced home cooks can accidentally add too much salt. When this happens, a few quick fixes can salvage your soup without starting from scratch.

Dilute with Unsalted Liquids

The most straightforward method for correcting an overly salty soup is to increase its volume with unsalted liquid. Add water, no-salt-added broth or stock, or unsalted dairy products like milk, cream, or yogurt, depending on your recipe.

For Brothy Soups: Gradually add water or low-sodium stock, stirring and tasting until the saltiness is reduced. If the soup becomes too thin, you can thicken it later with a cornstarch slurry or other thickener.
For Cream-Based Soups: Stir in a splash of milk, heavy cream, or sour cream. The fat in the dairy coats the mouth and helps temper the perception of saltiness while adding a desirable creaminess.

Add Acid to Balance Flavors

Just as acid can cut the richness of a dish, it can also balance out and distract from excessive saltiness.

Citrus Juice: A squeeze of fresh lemon or lime juice can brighten the soup's flavor and cut the salty intensity. This works particularly well in vegetable or lentil soups.
Vinegar: A dash of apple cider or white wine vinegar can provide the same effect. Start with a small amount and taste as you go to avoid adding a strong vinegar flavor.
Tomatoes: Canned or fresh tomatoes are naturally acidic and can be added to tomato-based soups like chili or minestrone to help restore balance.

Bulk It Up with Starchy or Fresh Ingredients

Increasing the solid ingredients in your soup can help distribute the salt more evenly and increase the volume, thereby reducing the sodium concentration per portion.

Starchy Vegetables: Add more diced, peeled potatoes, rice, or pasta. These starches will absorb some of the salty liquid and swell as they cook, helping to soak up the excess flavor.
Fresh Produce: Stir in extra fresh vegetables, such as carrots, celery, or spinach. As they cook, they will absorb some of the liquid and add their own natural flavors, balancing the dish.

The Potato Trick: Fact or Fiction?

The age-old kitchen hack of adding a raw potato to salty soup is a common remedy. The theory suggests the potato will absorb excess salt as it cooks. While the potato does absorb some liquid due to its starchy nature, its effect on overall saltiness is often mild at best. A potato's absorption power is limited, and it is more effective to increase the total volume of unsalted ingredients. However, it doesn't hurt to try if you have one on hand; just be sure to remove it before serving.

Preventing High Sodium in Homemade Soups

The best strategy for managing sodium is to prevent oversalting from the start. Making conscious choices while building your soup from scratch gives you complete control.

Choose Low-Sodium Ingredients

Low-Sodium Broths: Store-bought broths are often loaded with sodium. Opt for varieties labeled “no salt added” or “low-sodium”. Better yet, make your own homemade stock to control the sodium completely. If you use a regular broth, dilute it with an equal amount of water.
Canned Goods: Canned beans and vegetables are often preserved in a salty solution. Always drain and rinse canned goods thoroughly before adding them to your soup to reduce their sodium content by up to 40%.

Build Flavor with Alternatives

Create a rich flavor profile without relying on salt. This allows your taste buds to adjust and appreciate the natural flavors of the ingredients.

Aromatics: Sautéing vegetables like onions, garlic, carrots, and celery creates a flavorful base. Roasting vegetables beforehand can further intensify their natural, caramelized sweetness.
Herbs and Spices: Fresh and dried herbs, such as thyme, bay leaves, cumin, smoked paprika, and chili flakes, are excellent for adding depth. Freshly ground pepper also provides a flavor boost without any sodium.
Umami-Rich Ingredients: Ingredients that provide a savory, umami flavor can replace the need for extra salt. Mushrooms, nutritional yeast, tomato paste, and parmesan rinds are all fantastic options.

Taste as You Go

Seasoning in stages is a fundamental cooking practice. Add salt in small increments at different points in the cooking process and taste frequently. Remember that soup reduces as it simmers, which concentrates flavor—including salt. Wait until the end to adjust the final seasoning.

Reducing Sodium in Store-Bought Soup

For canned or store-bought soups, your options are more limited but still effective.

Dilute with Water or Unsalted Broth: Pouring out some of the broth and adding a no-salt-added version is the simplest way to reduce overall sodium. You can also bulk it up with fresh, unsalted vegetables.
Incorporate Unsalted Add-ins: Stir in unsalted pasta, potatoes, or fresh vegetables. This will reduce the sodium concentration per serving.
Add Acidic or Creamy Elements: Balance the flavor with a squeeze of lemon or a dollop of unsalted yogurt or sour cream before serving.

Comparison Table: Sodium Reduction Strategies


Method	Best For	Pros	Cons
Dilution	Any overly salty soup	Directly reduces total sodium; very reliable	Can water down other flavors and texture if not done carefully
Adding Acid	Soups that need a flavor lift	Balances and brightens the overall taste; quick fix	Does not actually reduce sodium content; only perception
Adding Starches	Brothy or chunky soups	Absorbs salt and adds bulk for a heartier meal	Primarily absorbs salty liquid, not the salt itself; can make soup thicker
Using Low-Sodium Ingredients	Preventing saltiness in homemade soup	Total control over sodium content; builds robust flavors naturally	Requires more careful sourcing and a recipe modification mindset
Incorporating Aromatics & Herbs	Enhancing flavor in any soup	Adds complex, sodium-free flavor to the dish	May require fresh ingredients, which might not be on hand

Conclusion

Whether you need to fix a quick mistake or adopt a healthier, low-sodium lifestyle, several effective strategies can help. By focusing on preventative measures like using unsalted ingredients and flavoring with fresh herbs and aromatics, you can achieve delicious and nourishing results. For immediate fixes, dilution and balancing with acid or dairy are reliable solutions. The key is to taste as you go and experiment with different flavor enhancers to create deeply satisfying soups without relying on excess salt. Mastering these techniques ensures that your soups are both healthy and packed with flavor. For more nutritional information on food ingredients, the U.S. Department of Agriculture's FoodData Central is a valuable resource.

USDA FoodData Central

Frequently Asked Questions

While a potato does absorb some liquid and may mildly help, it won't magically eliminate all the salt. The effect is often minimal. Diluting the soup with unsalted liquid or bulking it up with more low-sodium ingredients is a more effective strategy.

Adding a small amount of sweetness can help balance out the flavor profile and distract your palate from the saltiness, but it won't actually reduce the total sodium content.

The most effective method is to dilute it. You can pour out some of the salty broth and replace it with water or unsalted broth. You can also add more unsalted ingredients, such as cooked vegetables or pasta, to increase the volume and reduce the sodium per serving.

Focus on aromatics like sautéed garlic and onions, fresh herbs such as parsley and thyme, and spices like cumin and paprika. Umami-rich ingredients like mushrooms or nutritional yeast can also add depth.

It is best to add salt incrementally throughout the cooking process and taste as you go. Because soups concentrate as they simmer, it's a good practice to add the majority of your salt near the end to avoid oversalting.

Yes, rinsing canned beans and vegetables can reduce their sodium content significantly, by up to 40%. Always drain and rinse canned goods thoroughly before adding them to your soup to reduce hidden salt.

Homemade stock is the best option for complete control. For store-bought options, look for brands labeled “no salt added” or “low-sodium.” You can also use vegetable juice as a liquid base.