Laundry Bluing Is the Secret to Brighter, Whiter Clothes — Here’s How to Use It

I remember the first time I ever heard of laundry bluing. I was a tween reading one of the Anastasia Krupnik books in Lois Lowry’s beloved series. Krupnik had a penchant for hilarious mishaps, so when she added something called bluing to a load of white laundry, I braced for the worst. But no disaster ensued. After consulting a dictionary, I learned that bluing was a type of whitener, so there was no need for concern after all. 

Fast-forward to my adult life, in which I rely only on regular detergents and stain removers to launder all my clothes and linens. I don’t like to use bleach, unless it’s already part of a bathroom cleaning product, but wanted to find a way to whiten my clothes.

That’s when laundry bluing popped back on my radar. I saw an ad for Mrs. Stewart’s Concentrated Liquid Bluing, which has been around since 1883. I assumed it would be strong, but the bottle proclaimed it “whitened white clothes safely,” and I was surprised to see the words “nontoxic” and “biodegradable” on there.

Was this the fabric-friendly bleach alternative I’ve been looking for? And why is it blue? I decided it was time to investigate what laundry bluing is all about.

Bluing is typically referred to as an optical whitener. “It is a liquid additive containing Prussian blue pigment that creates an optical illusion by adding a blue tint to make yellow look white and bright,” explains Ocean Van, owner of Coco Laundry. 

Although white is technically not a color but rather an absence of color, there are many different shades of white. Color experts can likely distinguish more of them, but you’ve undoubtedly noticed the difference if you’ve ever held a white shirt you’ve washed and worn repeatedly up against a brand-new one. Not only will the new one appear as the brighter white, but you might even glimpse a blue hue to it. 

Here’s where bluing and not bleach comes in. The addition of bluing to a laundry load will make white clothes emerge brighter through that optical illusion. But you can’t just dump some bluing into your wash, or your clothes will turn out blue. Here’s how it’s done.

Reading labels saves loads of trouble and in the case of bluing, loads of laundry. In the case of Mrs. Stewart’s, you have to dilute just a few drops of product in 2 quarts of cold water, although you can use up to 1/4 teaspoon for larger loads. Add the diluted bluing to the wash or rinse cycle; yes, you’ll see it turn light sky blue, but this is normal. If you have a front-load washer, add the diluted bluing to the detergent dispenser once the machine has filled up with water.

Divert from these instructions at your peril. “A common mistake is adding too much bluing, which makes clothes noticeably blue,” Van says. “If this happens, you can remove the excess bluing by soaking the clothes in a mixture of cold water and household ammonia.”

While bluing does pull off the trick of making clothes appear whiter, it’s not necessarily the cure-all you’re looking for with laundry. Here, Van takes us through some of the advantages and disadvantages of making optical whiteners like bluing part of your normal laundry routine.

• It’s gentle on fabrics. “Bluing is nontoxic and safe for most fabrics, while bleach or bleach-based solution can weaken and damage fabric fibers over time,” Van explains.
• It’s color-safe. Unlike bleach, you can use it on both white and colored fabrics.
• It’s inexpensive. An 8-ounce bottle of Mrs. Stewart’s costs around $8. Considering you’re only using a few drops per load, that could last a long time.

• It won’t remove stains. It is not a stain remover, so you’ll still need to pretreat stains before doing laundry.
• It could cause stains. Turns out I wasn’t all that wrong to worry about bluing going awry. If you don’t dilute it first, you will end up with blue-tinged clothing.
• It doesn’t play well with others. While you can use regular detergent with bluing, don’t use it with chlorine bleach or fabric softener; Van says those combos can lead to discoloration.

I haven’t tried bluing myself just yet, but my bottle is on its way. I figure if something has been around since 1883, it must work.