Beans are a culinary cornerstone in kitchens around the world. Packed with protein, fiber, and essential nutrients, legumes like chickpeas, black beans, lentils, and kidney beans have made their way into soups, stews, salads, and plant-based dishes. But one question continues to puzzle home cooks: should you throw out bean water after soaking or cooking? This liquid—often referred to as “aquafaba” or “bean broth”—has been tossed into the sink for generations, but recent discoveries and culinary innovations are challenging traditional habits.
In this comprehensive guide, we dive deep into the world of bean water. We’ll explore its chemical composition, health implications, environmental impact, and culinary potential. Whether you’re a sustainability advocate, a health-focused eater, or a curious gourmet, this article will help you make an informed decision about what to do with that leftover bean liquid.
What Exactly Is Bean Water?
Bean water refers to the liquid that remains after soaking or cooking dried beans. While the term “bean water” is generic, the liquid from cooked chickpeas has garnered special attention in recent years under the name aquafaba, a portmanteau of “aqua” (water) and “fabaceae” (the legume family).
The Science Behind Bean Water
When dried beans are soaked or boiled in water, several compounds leach out into the liquid. These include:
- Soluble fibers (such as oligosaccharides like raffinose and stachyose)
- Starches and proteins
- Phytochemicals and antioxidants
- Minerals like potassium and magnesium
- Off-flavors and gas-producing compounds
The composition varies depending on the bean type, cooking method, and whether the beans were rinsed before soaking. For example, chickpea brine is rich in proteins and starches, making it particularly effective as an egg white substitute in vegan baking.
Why Bean Water Turns Cloudy
The cloudy appearance of bean water is due to the release of starches and proteins. While it might seem unappetizing, this cloudiness is actually a sign that beneficial compounds are dissolving into the liquid. However, it can also harbor substances that cause digestive discomfort—more on that later.
The Case for Discarding Bean Water
Despite its potential, many recipes and health experts advise discarding bean water. Let’s examine the reasoning behind this traditional practice.
Reduction of Digestive Discomfort
One of the primary reasons for tossing bean water is to minimize gastrointestinal side effects. Beans are well-known for causing gas and bloating, and these effects are largely due to oligosaccharides—complex sugars that humans cannot digest.
When beans are soaked or cooked, a significant portion of these sugars leaches into the water. Discarding the soaking or cooking liquid helps reduce the gas-producing compounds, making beans more digestible.
A study published in the journal Food Chemistry found that soaking beans and discarding the water reduced oligosaccharide content by up to 30%. This simple step can make a big difference for those with sensitive stomachs or conditions like irritable bowel syndrome (IBS).
Lowering Anti-Nutrients
Dried beans also contain anti-nutrients such as phytic acid and lectins. These naturally occurring compounds can interfere with the absorption of essential minerals like iron, zinc, and calcium.
Soaking and boiling beans in water help degrade these compounds. However, to maximize this benefit, it’s recommended to discard the soaking water rather than use it for cooking, as some anti-nutrients remain dissolved in the liquid.
Phytic acid reduction can be further enhanced by soaking beans in slightly acidic water (e.g., with a splash of vinegar or lemon juice) or by boiling for at least 10 minutes. Yet, even after such treatments, experts often recommend rinsing and starting fresh with clean water when cooking.
Removing Dirt and Residue
Commercial dried beans are not always pristine. They can carry dust, sand, or mold spores from storage and transport. While rinsing the beans helps, discarding the soaking water adds an extra layer of food safety, reducing the risk of consuming contaminants.
The Case for Keeping Bean Water
While discarding bean water has historical and health-based justification, new findings and eco-conscious practices argue strongly in favor of saving it.
Environmental and Economic Benefits
Every year, millions of gallons of nutrient-rich bean water are discarded globally—water that could be reused. In an era where food waste and sustainability are growing concerns, repurposing bean water becomes both an ecological and economic opportunity.
By saving the liquid, home cooks reduce water usage and waste. Additionally, the beans’ nutrients—especially protein and fiber—aren’t entirely lost in the water. Reusing bean water means you’re extracting maximum value from your food, aligning with zero-waste kitchen principles.
What Is Aquafaba and Why Does It Matter?
The term “aquafaba” vaulted into culinary stardom around 2015 when a French home cook discovered that the liquid from canned chickpeas could mimic egg whites. Since then, it has revolutionized vegan baking, offering a plant-based alternative for meringues, macarons, mayonnaise, and even cocktails.
| Property | Egg White | Aquafaba |
|---|---|---|
| Whipping Volume | High | Very High (up to 25x expansion) |
| Binding Ability | Strong | Moderate to Strong |
| Use in Meringue | Traditional | Excellent |
| Source | Animal | Plant (bean water) |
One tablespoon of aquafaba can replace one egg white in most recipes. Three tablespoons typically equals a whole egg, making it an invaluable tool in allergen-free and vegan cooking.
How to Use Aquafaba in Your Kitchen
- Whip it: Use in place of egg whites to make vegan meringues, mousses, or marshmallows.
- Bind it: Substitute in baked goods like pancakes, cookies, or cakes.
- Emulsify it: Use in vegan mayonnaise, aioli, or salad dressings.
- Thicken it: Add to soups and sauces for body and texture.
Note: Aquafaba from canned beans usually has a higher salt content. For baking applications, use from home-cooked beans whenever possible, or reduce added salt in your recipe.
Enhancing Flavor and Nutrition in Cooking
Bean water isn’t just for vegans or bakers. It’s also a flavorful, nutrient-rich broth that can elevate homemade soups, stews, and gravies.
Because it contains starches and soluble fibers, bean water acts as a natural thickener—similar to a light roux or slurry—without adding extra ingredients. This makes it ideal for enriching vegan chili, lentil soup, or creamy bean dips.
Moreover, by retaining the cooking liquid, you preserve some of the water-soluble vitamins and minerals that would otherwise be lost. While beans remain the primary source of nutrients, the liquid still contributes to overall food value.
Home Remedies and Beauty Uses
Some traditional and holistic health practices incorporate bean water beyond the kitchen. For instance, diluted bean water is used as a natural hair rinse or skin toner due to its protein and starch content, which may help strengthen hair and reduce inflammation.
While scientific studies on these uses are limited, anecdotal evidence suggests potential benefits—especially for those seeking chemical-free personal care alternatives.
Practical Guidelines: When to Keep or Toss Bean Water
The answer to “should you throw out bean water?” isn’t always black and white. It depends on your goals: digestion, nutrition, sustainability, or culinary creativity.
Situation 1: You’re Trying to Minimize Bloating
If digestive comfort is your priority, discard the soaking water and rinse beans thoroughly before cooking. Cook beans in fresh water to minimize oligosaccharide intake. This is especially helpful if you’re new to eating legumes or have a sensitive digestive system.
Tips for Easier Digestion:
- Soak beans for 8–12 hours, then discard the water.
- Cook beans at a rolling boil for at least 10 minutes to deactivate lectins.
- Add kombu seaweed during cooking—it contains enzymes that help break down gas-producing sugars.
- Introduce beans gradually into your diet to allow your gut flora to adapt.
Situation 2: You’re Cooking from Scratch and Want Zero Waste
For environmentally conscious cooks, discarding bean water feels wasteful. The good news? You can have your beans and keep the water too—with smart preparation.
Here’s how:
- Soak the beans as usual.
- Instead of discarding the soaking water, bring it to a rolling boil for at least 10–15 minutes. This helps break down oligosaccharides and lectins.
- Continue cooking the beans in the same water—now safe and nutritious.
- Reserve the resulting broth for soups, sauces, or aquafaba applications.
This method reduces waste without compromising safety or digestibility.
Situation 3: You’re Vegan or Baking Without Eggs
If you’re creating vegan meringues, cookies, or other egg-replacement recipes, bean water (specifically from chickpeas) is a kitchen treasure. Save the liquid from canned or home-cooked chickpeas in an airtight container in the refrigerator for up to 5 days, or freeze it in ice cube trays for longer storage.
Pro tip: Reduce aquafaba by simmering it to concentrate its proteins and improve performance in recipes.
Situation 4: You’re Making Soups or Stews
In traditional dishes like feijoada (Brazilian black bean stew) or Italian pasta e fagioli, bean water is intentionally kept and used as part of the broth. Not only does it enrich flavor, but it also contributes creaminess and texture.
In fact, commercial canned beans often lose their culinary appeal due to the absence of bean water in the final product—unless the can explicitly says “in bean broth.” This is why many chefs prefer cooking dried beans from scratch when making hearty legume-based meals.
Bean Water by Bean Type: What You Need to Know
Not all bean water is created equal. The usefulness and safety of the liquid depend heavily on the bean variety.
Chickpeas (Garbanzo Beans)
Chickpea water is the gold standard for aquafaba. It has high protein and starch content, making it effective at emulsifying and foaming. Whether from canned or cooked, this liquid can be used in numerous vegan applications.
Black Beans, Kidney Beans, and Pinto Beans
The cooking liquid from these beans tends to be darker and higher in starch, making it excellent for thickening soups and chili. However, flavor and digestibility vary.
- Best use: As a base for bean soups or vegetarian stews.
- Caution: May cause more gas if not cooked thoroughly.
Lentils and Split Peas
These legumes break down more easily during cooking, so their water is often very starchy and murky. While perfectly safe, it may not whip like aquafaba but can still be used as a soup thickener.
Canned Beans: A Special Case
Canned beans come pre-cooked in salted water, often with added preservatives or firming agents (like calcium chloride). While the liquid is technically “bean water,” it comes with trade-offs:
- High sodium content may be unsuitable for low-salt diets.
- Added preservatives could interfere with certain recipes.
- Still usable for aquafaba in a pinch, but taste and performance may vary.
Always check the ingredient list. If the only ingredients are beans, water, and salt, the liquid is likely safe to use. Otherwise, rinsing and discarding may be the wiser choice.
Debunking Common Myths About Bean Water
Let’s clear up some misconceptions that may be influencing your decision.
Myth 1: Bean Water Is Toxic
This myth stems from concerns about lectins in raw or undercooked beans. While it’s true that raw kidney beans contain phytohaemagglutinin—a toxin that can cause severe nausea—proper boiling (at least 10 minutes) eliminates this risk. Cooking in or reusing the soaking water is safe once beans are thoroughly cooked.
Myth 2: All Bean Water Works Like Aquafaba
Not true. While chickpea brine is the most effective, other bean waters vary in whipping capability. For example, black bean water generally doesn’t whip well and has a stronger flavor that may not suit delicate desserts.
Myth 3: Bean Water Has No Nutritional Value
Research shows that bean water contains measurable amounts of protein, fiber, and micronutrients. While not as nutrient-dense as the beans themselves, discarding it means losing a small but significant portion of their nutritional profile.
Sustainable Kitchen Practices: A Few Final Tips
To make the most of your beans—both in and out of the pot—consider incorporating these sustainable habits:
Label and Freeze Bean Water
If you don’t plan to use the liquid right away, freeze it in labeled containers. Ice cube trays are ideal for small portions used in sauces or dressings.
Compost When in Doubt
If you’re uncertain about the safety or quality of your bean water, avoid pouring large amounts down the drain. Instead, dilute and compost it—its nutrient content can enrich soil.
Use in Gardening (With Caution)
Some gardeners use diluted bean water as a liquid fertilizer due to its mineral content. However, because it can ferment and attract pests, it should be used sparingly and only when fresh.
Conclusion: To Keep or To Toss—It’s Your Call
So, should you throw out bean water? The answer depends on your priorities.
- For better digestion and reduced bloating: Yes, discard the soaking water and cook beans in fresh water.
- For sustainability and zero-waste cooking: No, boil the soaking water and continue using it to cook—especially if you’re making soups or stews.
- For vegan baking or egg substitution: Absolutely keep it—especially if it’s chickpea water.
- For health and nutrition: Maximize nutrient retention by using the cooking liquid, but ensure beans are properly boiled to eliminate risks.
Rather than following rigid rules, the modern kitchen thrives on informed choices. Bean water doesn’t have to be wasted—it can be a valuable ingredient, a tool for sustainability, or a solution for dietary needs. By understanding its properties and potential, you can transform what was once considered trash into a culinary gem.
The next time you cook a pot of beans, pause before you pour. That water might just be the secret ingredient you never knew you had.
Why is bean water often discarded after cooking?
Bean water, also known as aquafaba, is commonly thrown out because many people associate it with causing digestive discomfort. During the soaking and cooking process, beans release oligosaccharides—complex sugars that humans cannot fully digest—which end up in the cooking liquid. These sugars can contribute to bloating and gas when consumed, especially in individuals with sensitive digestive systems. As a result, the instinct is to discard the liquid to minimize potential gastrointestinal issues.
Additionally, bean water can appear cloudy and contain starches, impurities, and residues from the beans, which some perceive as unappetizing or unclean. Traditional recipes often call for draining and rinsing beans before use, reinforcing the idea that the liquid should be discarded. However, this practice may result in the loss of valuable nutrients and culinary opportunities, especially since the liquid contains water-soluble vitamins and minerals that leach from the beans during cooking.
What is aquafaba and how is it useful?
Aquafaba is the viscous cooking liquid left after preparing legumes, particularly chickpeas. It has gained popularity in recent years as a vegan substitute for egg whites due to its remarkable ability to mimic the binding, foaming, and emulsifying properties of eggs. When whipped, aquafaba forms stiff peaks similar to egg whites, making it ideal for meringues, mousses, and other desserts. It is especially valuable in plant-based baking where traditional egg replacements fall short.
Beyond desserts, aquafaba can be used in savory dishes such as mayonnaise, salad dressings, and even as a broth enhancer. Its neutral flavor and functional properties make it versatile in both cooking and food manufacturing. Instead of discarding bean water, especially from canned or home-cooked chickpeas, saving and using aquafaba promotes sustainability by reducing food waste and offers creative, dairy- and egg-free alternatives in the kitchen.
Does bean water contain nutrients?
Yes, bean water contains a variety of nutrients that leach from the beans during soaking and cooking. Water-soluble vitamins such as B vitamins—including folate and thiamine—and certain minerals like potassium, magnesium, and iron can dissolve into the cooking liquid. Retaining and consuming the bean water can help you maximize the nutritional benefits of the beans, especially if you’re using dried beans that have been cooked from scratch.
However, the nutrient concentration in bean water is generally lower than in the beans themselves, and the presence of anti-nutrients like phytic acid may slightly reduce mineral absorption. Despite this, the liquid still contributes to overall nutrient intake when used in soups, sauces, or stews. To optimize both nutrition and digestibility, consider using the bean water in cooked dishes rather than consuming it plain.
Can bean water improve the texture of dishes?
Absolutely. Bean water is rich in starches and natural gums released during cooking, which can act as thickeners and emulsifiers in various recipes. When added to soups, chilis, or stews, it helps create a creamier, more cohesive texture without altering the flavor significantly. This is particularly useful in vegetarian and vegan cooking, where achieving hearty consistency without dairy or meat stock can be a challenge.
Moreover, when using pureed beans in dips or spreads, incorporating some of the cooking liquid can prevent dryness and improve mouthfeel. For example, adding bean water to hummus allows for a smoother, silkier consistency while reducing the need for excess oil. The starches in the liquid also help bind ingredients together in veggie burgers or falafel, enhancing structural integrity during cooking.
Is it safe to consume bean water every time?
In most cases, consuming bean water is safe, especially when beans have been properly soaked and cooked. Thorough cooking helps break down potentially harmful compounds and reduces levels of digestive irritants. If you’ve cooked dried beans at home using a long soak and boil method, the resulting liquid is generally safe to consume in moderation, particularly when incorporated into cooked dishes.
However, there are exceptions. Bean water from canned beans often contains high levels of sodium and preservatives, making it less ideal for direct consumption. Additionally, individuals with specific digestive sensitivities may find that even cooked bean water exacerbates bloating or gas. If you’re prone to digestive issues, start by using small amounts and monitor your body’s response. When in doubt, err on the side of caution and discard canned bean liquid.
How should bean water be stored for later use?
If you plan to reuse bean water, it should be treated like any perishable cooking liquid. Allow it to cool to room temperature after cooking, then transfer it to an airtight container and refrigerate. Properly stored, fresh bean water can last for up to 5–7 days in the refrigerator. For longer storage, it can be frozen in ice cube trays or small containers and kept for up to three months.
When freezing, label the container with the date and type of beans used, as different legumes produce slightly different viscosities and flavors in their liquid. Thaw frozen bean water in the refrigerator or gently warm it as needed. Avoid repeated freezing and thawing, as this can degrade quality. Storing bean water properly ensures you can take advantage of its culinary benefits without waste.
Are there any environmental or economic benefits to using bean water?
Using bean water instead of discarding it contributes to more sustainable and economical cooking practices. Throwing out nutrient-rich liquid increases household food waste, which has broader environmental consequences, including higher landfill contributions and wasted resources used in food production. By repurposing bean water into sauces, broths, or baked goods, you reduce waste and make better use of the ingredients you’ve already purchased.
Economically, reusing bean water can save money, especially in plant-based or specialty diets that rely on egg substitutes. Commercial aquafaba products and vegan egg replacements can be expensive, while homemade versions cost nothing extra. In addition, using bean water as a thickener may reduce the need for other ingredients like flour, oil, or starches. These small savings can add up over time, making it a practical habit for frugal and environmentally conscious cooks.