Washing Soda vs. Baking Soda: How Do They Differ, and Which One Is Better for Your Laundry?

Have you found yourself lost in the vortex of #CleanTok? Are you rethinking your cleaning habits and evaluating the products you use? If your focus is now on baking soda and washing soda, questioning how they could possibly be so different, you're definitely not the only one.

While many people use these two products interchangeably in conversation and application, it’s easy to see why—both are white, powdery substances, and both include 'soda' in their names. They're also classic cleaning agents, often found in DIY solutions like scrubs and deodorizers. (Washing soda, in particular, gained popularity thanks to the laundry stripping trend that TikTok embraced in 2020 and continues to buzz about.) So yes, they are similar, but they are certainly not the same.

To settle the confusion surrounding these two ingredients, we spoke with Arm & Hammer, the product leader in both baking soda and washing soda. We also consulted a dry-cleaning expert (and laundry product-testing guru!) for their advice on how to maximize each product's performance. Let’s dive into the ‘washing soda vs. baking soda’ discussion.

What Is Washing Soda?

Washing soda (also known as soda ash) is a naturally occurring chemical compound, scientifically known as sodium carbonate (Na₂CO₃). Historically, it was produced from plant ash, but today it is mainly mined. According to Lisa Muentener, a research and development expert at Arm & Hammer, washing soda is now extracted from trona ore in the United States, with the largest deposit located in Wyoming.

As Muentener explains, washing soda is highly alkaline with a pH of 11, making it very effective at removing stains and grease. To put it in perspective, dish soap has a pH between 7 and 10, while bleach ranges from 11 to 13. This means washing soda is more potent than dish soap and almost as strong as bleach, which is why it’s remained a go-to for so many cleaning tasks.

Zachary Pozniak, the vice president of operations at Jeeves New York dry cleaning service, tests numerous laundry products on social media and confirms that washing soda is a key ingredient in most powdered detergents. “It’s a stronger base than its cousin, sodium bicarbonate (or baking soda),” he explains.

Household Uses

Washing soda is mainly used to tackle greasy dirt and food stains on clothing, and it boosts the effectiveness of other laundry products by softening hard water. Hard water can interfere with detergent’s ability to dissolve and lather properly, making cleaning less effective. Additionally, hard water leaves mineral residues that can make fabrics feel stiff, but washing soda helps reduce these issues.

Pozniak suggests adding washing soda directly into your machine's drum before loading clothes (follow the package instructions for the correct amount). However, his favorite method is to mix washing soda with equal parts borax and powdered oxygen bleach, creating a laundry booster for particularly smelly or dirty loads. He recommends adding about ¼ cup of the mixture to a full load. But be cautious, as he warns, 'Using too much can speed up fabric wear and tear.'

Beyond laundry, washing soda is also a powerful cleaner for kitchen surfaces, appliances, pots and pans, and upholstery.

What Is Baking Soda?

Baking soda is sodium bicarbonate (NaHCO₃). According to Muentener, this compound contains half the sodium of sodium carbonate (washing soda), making baking soda and washing soda chemically very similar. In fact, most baking soda is derived from washing soda! Sodium carbonate extracted from trona ore is converted into sodium bicarbonate when carbon dioxide is introduced during production.

Baking soda is mildly alkaline, with a pH of 8.4. Muentener highlights that what makes baking soda unique is its ability to function as both an acid and a base. 'It can neutralize both acidic and basic volatile odors, turning them into non-volatile salts,' she says. This is why baking soda is so effective at eliminating a wide range of unpleasant smells.

Household Uses

In addition to being a key ingredient in baking for leavening, baking soda is widely used as a cleaning agent around the home. It's commonly found in products that deodorize refrigerators, litter boxes, upholstery, carpets, and even laundry. Baking soda is also used to make a paste, which serves as a gentle, scratch-free scrub for various surfaces like ceramic and stainless steel.

While baking soda isn’t as famous as washing soda in the laundry room, Pozniak argues that it can still be useful in the wash when used properly. Although milder than washing soda, it can raise the pH of wash water, enhancing detergent performance. 'Baking soda is one of the best ways to remove particulate stains—like dirt, mud, and sand—because it breaks up metallic bonds,' says Pozniak. Instead of soaking, he recommends adding it directly to the washing machine drum for better results, using about ½ cup per load.

Key Differences Between Baking Soda and Washing Soda

As we mentioned earlier, while baking soda and washing soda share a similar chemical composition, they are not the same and should not always be swapped. (For example, never use washing soda in a recipe.) Let’s explore how these two differ.

Physical Differences

In terms of texture, Muentener notes that baking soda is typically a bright white or off-white powder, with a fine, smooth texture resembling flour or powdered sugar. On the other hand, washing soda tends to have larger, coarser crystals or granules. It’s grainier and often appears dull or grayish. 'Washing soda might look less 'pure' or 'clean' compared to baking soda,' Muentener explains.

Functional Differences

Due to its high pH, washing soda is more caustic than baking soda and is primarily used in laundry to remove stains, soften water, and enhance the effectiveness of detergent. It’s used more sparingly than baking soda because of its harsher nature. Muentener suggests using caution when handling washing soda as it can irritate the skin and eyes, so wearing gloves may be wise if you have sensitive skin.

Baking soda offers more versatility outside the laundry room. While it's a staple in baking, it also works effectively as a deodorizer throughout the house. It’s commonly used in scrubs, with one popular mix being baking soda and hydrogen peroxide, which brightens and removes stains from surfaces such as grout.

Is Baking Soda or Washing Soda Better for Laundry?

Baking soda is often used with detergent to tackle odors and can help boost detergent performance as well as tackle some stains. However, washing soda is the go-to choice for more challenging laundry tasks. Baking soda is gentler and less effective than washing soda, which is essentially a stronger version. Washing soda is better at removing stains and brightening clothes, which is why it’s typically included in laundry stripping recipes, while baking soda is not. That said, washing soda can be rough on fabrics, especially when overused, so it’s important to use it sparingly to preserve the life of your clothing.