How to Dry Pillows Properly: The Tennis Ball Method

Why Drying Technique Matters

Plenty of people know they can put their pillows in the dryer. Fewer people know how to do it well. The difference between a properly dried pillow and a poorly dried one is significant: a properly dried down pillow comes out fluffy, fresh, and fully lofted. A poorly dried one comes out dense, flat, clumped, and possibly still damp in the centre -- setting up conditions for mould growth inside the fill.

This article is for people who already know their pillow is dryer-safe (synthetic fill, down, or feather) and want to know the technique that actually works. For guidance on which pillow types cannot go in the dryer at all (memory foam, latex, buckwheat), see our separate fill-type guide.

The Tennis Ball Trick and Why It Works

The most common advice for drying down and synthetic fill pillows is to add clean tennis balls to the dryer. This works, and there is a straightforward physical reason why:

When a pillow with wet fill tumbles in a dryer, the fill -- whether it's down clusters or hollow polyester fibres -- is heavy with absorbed water. As the fill dries, the water weight decreases, but the fill pieces can stick together and mat into dense clumps. Once these clumps form during drying, they're very difficult to break apart afterward, and the pillow ends up with flat, hard spots where the fill compacted.

Tennis balls solve this by adding mechanical disruption to the tumbling process. They bounce around the drum and periodically impact the pillow directly. Each impact compresses a section of the pillow briefly, then releases it -- physically preventing the wet fill from settling into a static clumped position. The fill is continuously agitated throughout the drying cycle, which means it dries in a more distributed state and maintains its loft.

Use 2 to 3 tennis balls for a standard pillow. A flat, worn-out tennis ball doesn't provide as much impact as a newer one. Clean tennis balls are best -- dirty balls can transfer stains or debris to a clean pillow cover.

Wool Dryer Balls: The Better Alternative

Wool dryer balls have become the preferred alternative to tennis balls for most household use. They work on the same principle -- mechanical disruption during tumbling -- but have some practical advantages:

• No synthetic chemicals: Wool is a natural material. Unlike rubber tennis balls, wool dryer balls don't transfer any rubbery smell or chemical residue to the pillow or other laundry, especially at the low heat settings needed for pillows.
• More durable: A good set of wool dryer balls lasts hundreds of dryer loads before needing replacement. A set of tennis balls may be fine for a few dozen loads, but the felt exterior can separate over time.
• Slightly faster drying: Wool dryer balls improve airflow in the drum and help absorb some moisture from the air during the cycle, which can marginally reduce total drying time.
• No noise concern: Tennis balls make a noticeable thumping sound during the dryer cycle, which some people find disruptive. Wool dryer balls are quieter.

Use 3 to 4 wool dryer balls for a pillow. Dryer balls can be used with other laundry too -- they work well for towels and duvets as well as pillows.

Heat Setting Guide

The heat setting for drying pillows should always be low or medium-low. This applies to both synthetic and down fill. High heat causes two problems:

1. It can melt or fuse hollow polyester fibres in synthetic fill, permanently damaging the fill structure.
2. It can damage down clusters and may burn feather quills in feather or down-and-feather blend pillows.

Low heat takes longer than high heat, but the result is a well-preserved pillow rather than one with damaged fill. Most dryers have settings labelled Low, Medium, High, and Air/Fluff. Use Low for pillows in every case. If your dryer runs warm even on Low (some older models do), check the pillow more frequently and feel for any unusual smells.

The Air/Fluff setting (no heat) can be used for a final cycle after the pillow is essentially dry, to do a final fluffing pass without heat.

How Many Cycles Does It Take?

This is where many people get it wrong. They run one dryer cycle, check the outside of the pillow, declare it dry, and put it back on the bed. Then the damp centre develops mould over the following weeks.

One cycle is not enough for most pillows. Here's the realistic picture:

Between each dryer cycle, take the pillow out, give it a firm manual fluff (squeeze and reshape, pulling the fill apart), and return it to the dryer. This manual redistribution step supplements the tennis ball action and helps stubborn clumps break up.

How to Tell If the Pillow Is Fully Dry

Do not rely on the exterior of the pillow to judge dryness. Pillow covers dry faster than the fill inside. The centre of the pillow retains moisture longest.

The correct check:

1. Remove the pillow from the dryer immediately after the cycle ends (before it cools and redistributes moisture).
2. Hold the pillow firmly with both hands and squeeze the very centre through the pillow cover, as hard as you can manage.
3. Pay attention to the sensation. A dry pillow has a consistent, light, dry feel throughout. A pillow with residual moisture in the centre feels slightly cool, slightly dense, or yields a faint damp sensation when squeezed hard.
4. If in doubt, run another cycle.

For down pillows specifically, you can also hold the pillow up and smell the squeezed area through the cover. A fully dry down pillow has no smell, or a clean, faintly warm smell. A pillow with residual damp smells slightly like wet dog or barnyard -- this is normal for damp down and it means more drying is needed.

What Properly Dried Down Smells Like (vs. Not Done)

This deserves its own section because it's a reliable field check that doesn't require any tools.

Down comes from ducks or geese and has a natural animal protein smell when wet. Fresh, clean down that is not fully dry will smell somewhat like a wet dog -- not strongly, but noticeably. This smell is not contamination and does not mean the pillow is bad. It's simply the smell of damp natural down.

A properly and fully dried down pillow has no discernible smell when you hold it up and smell it through the cover. Maybe a faint warm, clean-laundry smell, but nothing noticeably animal or damp.

If you make the bed with a down pillow that still has the damp-animal smell, it needs more time in the dryer. Go back for another full low-heat cycle with the tennis or wool dryer balls.

Related: Best Pillow for Side Sleepers in Canada (2026 Guide)

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What to Do Before Drying

A few steps before the drying cycle improve the outcome:

• Wash first. Pillows should be washed before drying if the reason you're drying them is hygiene maintenance. Wash synthetic and down pillows on a gentle cycle, warm water, with a small amount of gentle detergent. Run through an extra rinse cycle to ensure no detergent residue remains (detergent residue in down can cause clumping and smell).
• Spin well. Run the washing machine's full spin cycle to remove as much water as possible before transferring to the dryer. More water removed in the spin = less drying time needed.
• Inspect for damage. Check the pillow seams before drying. A loose or damaged seam means fill may escape into the dryer. Repair or hand-stitch the seam before drying if needed.
• Check the dryer drum. Make sure the dryer drum is clean and there are no residual dryer sheet chemicals or lint that could affect the pillow.

Quick Reference by Fill Type

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