Does the Tennis Balls in Dryer Trick Really Work to Soften Clothes?

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Open door  of dryer with blue bed sheets inside close up
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Everyone has a few home and cleaning tips they’ve been taught that, to be honest, may or may not even work—whether that’s using newspaper to clean glass, rubbing strongly-scented dryer sheets on clothes to keep bugs away, or polishing shoes with banana peels. One laundry hack that often gets tossed around is putting tennis balls in a dryer to soften your clothes and dry them faster. To prove or possibly debunk this hack, we looked to science and did a bit of sleuthing to see if this really does work, and if so, why?

Why put tennis balls in the dryer?

The belief is that tennis balls can soften items in the dryer as well as speed up the amount of time it takes to fully dry. Luckily, the trick does seem to work, so rather than resorting to a chemical-based fabric softener, you can simply toss in a few tennis balls (as long as they’re clean!).

How do they work?

The wool or nylon shell of the tennis balls ruffle the fibers of fabric on clothing and bedding, which helps to soften the material. Wool is also known for its ability to absorb water, and what makes this trick extra effective is how wool and water react to create heat. How Stuff Works explains this process: “The hydrogen bond of water, H2O, is actually broken, creating a chemical reaction with the wool fiber molecules to generate heat when it has taken on a lot of moisture.”

So while the wool balls are softening, they’re also adding some heat, which leads to how the balls themselves actually speed up drying time. The physical presence of a tennis ball causes more movement and space between items, which lets in more air, leading to drier clothing. Some of the best items tennis balls can soften and speed up the drying process for are bulkier things like freshly washed pillows and clean comforters.

What about dryer balls instead of tennis balls?

Dryer balls are great, too, and work in a very similar way to tennis balls. The only real main difference between the two is what they’re made out of. Dryer balls come in a variety of different materials like wool, plastic, and rubber, whereas standard tennis balls are made of felt or nylon and rubber.

Are there risks to putting tennis balls in the dryer?

There’s nothing too risky about adding tennis balls to your laundry. Like with anything that has rubber on it, it can heat and burn to produce a super unpleasant smell. If you’re worried about the scent, lower the temperature for the cycle you’re adding the tennis balls to, or let your items start drying for a bit and add the tennis balls later into the cycle.

Similarly to brightly-colored fabrics, the dye from tennis balls has a slight chance of running, so just double check that they’re colorfast before you put them in with your load of whites.

So, next time you go to do laundry, try tossing a few tennis balls in for a quicker dry time and ultra soft fabric.