Drying a Down Duvet: Temperature, Duration, and the Tennis Ball Method

Short answer: Down comforters must be dried in a dryer — air drying leads to clumping and mold risk. Dry at a low temperature (max. 60 °C), place 2–3 clean tennis balls in the drum, and plan for 3–4 drying cycles. In between cycles, remove the comforter and fluff it by hand. The comforter is only ready when no more damp clumps can be felt.

You've just washed your down comforter — now what? The most common mistake happens right now: the comforter is hung on the line and air-dried for a few days. This sounds gentle, but it's the worst thing you can do to a down comforter.

In this guide, we explain why a dryer is mandatory for down, what the correct temperature and duration are, and how the famous tennis ball method really works. No half-knowledge — but the instructions of a manufacturer who has been producing and testing down comforters for 30 years.

Last updated: April 2026

Why a dryer is mandatory for down comforters

Down consists of fine, three-dimensional flakes that trap air. These air pockets provide warmth and loft. When down gets wet, the fine barbs stick together and form clumps. If the comforter dries slowly in the air, two things happen:

• The clumps harden: The longer the down stays wet, the more firmly it clumps together. After 2-3 days of air drying, many clumps will no longer break apart — even with subsequent shaking.
• Risk of mold: A soaked down comforter takes 3-5 days to air dry. During this time, mold can form in the damp down clumps — invisible but noticeable by smell. The typical "musty" smell after washing is almost always a sign of too slow drying.

The dryer solves both problems: the mechanical motion of the drum combined with warm air quickly dries the down and fluffs it at the same time. What takes 4 days in the air, the dryer accomplishes in 3-4 hours — and the result is better.

Exception: If you don't have a dryer and can't use a laundromat, have the comforter professionally cleaned. Professional wet cleaning always includes machine drying.

The right temperature: Max. 60 °C

Temperature is the most critical factor when drying a down comforter. Too hot destroys the down, too cold unnecessarily prolongs drying time and promotes re-clumping.

Why max. 60 °C?

Down has a natural fat film (lanolin) that keeps it supple and water-repellent. At temperatures above 60 °C, this fat film is attacked. The result: the down becomes brittle, loses its loft, and breaks more easily. A down comforter that is regularly dried at 80 °C will have its lifespan shortened by several years.

The ideal temperature by comforter type

• New down comforter (first wash): 40–50 °C. A gentle start so the down gets used to the drum movement.
• Regular wash: 50–60 °C. The standard range for all BEFA down comforters.
• Older comforters (5+ years): 40–50 °C. Older down is more delicate — lower temperature, but more cycles.

Most dryers have a "delicate" or "easy care" program that operates at approx. 60 °C. This program is ideal for down comforters. Avoid programs like "cotton intensive" — these operate at 70–80 °C and are too hot.

The tennis ball method: How it really works

The tennis ball method is the most cited tip for drying down comforters — and it actually works. But many don't know why it works and therefore make mistakes in its application.

The principle

Tennis balls bounce against the wet down comforter in the rotating drum and mechanically "beat" apart the clumped down. Without the balls, the comforter would rotate in the drum as a compact clump — the surface dries, but the inside remains wet and clumped. The tennis balls break up this structure and ensure even drying.

Correct application

• Quantity: 2–3 tennis balls. More do not provide additional benefit and only generate noise.
• Condition: Clean, odorless tennis balls. Used balls from the tennis court can leave stains. It's best to use new, inexpensive balls — no high-quality game balls are necessary.
• Alternative: Wool dryer balls work just as well and are quieter. Available in specialty stores and online.
• Not suitable: Golf balls (too hard, can damage the cover fabric), plastic balls (can melt).

Step-by-step: How to properly dry a down comforter

Here are the complete instructions on how to properly dry your down comforter after washing. We recommend setting aside half a day for this — 3-4 drying cycles take a total of 3-5 hours.

Step 1: Remove comforter from washing machine

Remove it from the machine immediately after spinning. Do not leave it folded — moisture will build up and the down will clump faster. Loosely spread out the comforter and give it a good shake.

Step 2: First drying cycle (60–90 minutes)

Place the comforter loosely in the dryer — do not fold or stuff it. Add 2–3 tennis balls or dryer balls. Program: Delicate drying at max. 60 °C. Duration: 60–90 minutes.

Step 3: Remove and fluff

After the first cycle, remove the comforter. It will still feel damp and lumpy — this is normal. Fluff the comforter vigorously and gently loosen any down clumps with your hands. Pay particular attention to the corners and edges — this is where most moisture collects.

Step 4: Second and third cycle (45–60 minutes each)

Return to the dryer, again with tennis balls. After each cycle, remove, fluff, and loosen clumps. With each cycle, the comforter should feel noticeably lighter and fluffier.

Step 5: Drying check

Reach into the middle of the comforter and squeeze the filling. If you can still feel damp clumps or if the comforter feels heavier than before washing, it needs another cycle. Better one cycle too many than one too few — residual moisture leads to mold.

Step 6: Allow to cool

Spread the freshly dried comforter on the bed and allow it to cool for 2–3 hours before putting on the duvet cover. During this time, the down will distribute evenly in the chambers and any residual heat from the dryer will dissipate.

The 5 most common drying mistakes

From 30 years of customer feedback, we know the most common mistakes. Each one can permanently damage a down comforter:

1. Air drying on the line: The most common and worst mistake. The down clumps irreversibly, and mold can form in the damp clumps. Down comforters belong in the dryer — no exceptions.
2. Too high a temperature: Programs above 60 °C damage the fat film of the down. The result: the down becomes brittle and loses its loft. The comforter will then feel flatter and provide less warmth.
3. Only one drying cycle: A single cycle is never enough. The comforter feels dry on the outside but is still damp at its core. Residual moisture = risk of mold. Plan for at least 3 cycles.
4. No tennis balls / dryer balls: Without mechanical help, the comforter dries as a compact block. The outside becomes bone dry, the middle remains damp. The tennis balls break up the clumps and allow for even drying.
5. Straight into the duvet cover after drying: Even after the last drying cycle, the comforter still contains minimal residual heat and moisture. Allow the comforter to cool on the bed for 2-3 hours before putting on the duvet cover.

Dryer vs. air drying vs. professional cleaning

Criterion	Dryer (household)	Air drying	Professional cleaning
Duration	3–5 hours	3–5 days	1–3 business days
Result	Very good	Poor (clumping)	Very good
Cost	approx. €2–3 electricity	€0	€30–60
Mold risk	Very low	High	None
Loft afterwards	100 % (if correctly applied)	50–70 % (irreversible loss)	100 %
Minimum drum size	7–9 kg (depending on comforter size)	—	—

Conclusion: The household dryer is the best solution for most down comforter owners. Professional cleaning is worthwhile for oversized comforters (200x220, 240x220) that do not fit into a household dryer. Air drying is not an option.

How BEFA tests drying capability

As a manufacturer, we not only test the thermal performance of our comforters but also their washing and drying properties. Three things make BEFA down comforters particularly drying-friendly:

1. Cover fabric with optimal air permeability: The cotton cover fabric (downproof weave) must be down-tight, but still allow air exchange. We test air permeability according to DIN EN 12132 — too dense fabric drastically prolongs drying time.
2. Class 1 down with high resilience: High-quality down recovers faster after washing — it declumps more easily and reaches its full loft after just 2-3 drying cycles. Cheap down with a high feather content requires 5+ cycles and still doesn't reach its original loft.
3. Baffle box construction with defined chambers: The down can move freely within the chambers but cannot migrate through the dividers. This allows for even drying and prevents all the down from shifting into one corner of the comforter. You can read more about this in our buying guide article.

BEFA Down Duvets — Washable and Tumble-Dryer Suitable

Frequently Asked Questions

Can you air-dry a down duvet?

No. Air-drying is the most common reason for permanently clumpy down duvets. The drying time of 3–5 days leads to irreversible clumping and risk of mold. Down duvets must be tumble-dried.

What temperature should you use for down duvets in the dryer?

Maximum 60 °C. Most dryers have a "delicate" or "easy-care" program that operates in this range. Temperatures above 60 °C damage the natural oil film of the down and shorten the duvet's lifespan.

How many drying cycles does a down duvet need?

At least 3, often 4 cycles. After each cycle, remove, shake out, and manually loosen any clumps of down. The duvet is only ready when no more damp clumps can be felt. A winter duvet with a lot of filling often needs 5 cycles.

Why put tennis balls in the dryer?

Tennis balls bounce against the wet duvet as it rotates, mechanically fluffing up clumped down. Without them, the duvet dries as a compact block — dry on the outside, damp and clumped on the inside. 2–3 clean tennis balls or felt dryer balls are sufficient.

How long does it take to dry a down duvet?

In the dryer, a total of 3–5 hours (spread over 3–4 cycles with breaks for shaking). A single duvet 135x200 finishes faster than an oversized 240x220. Plan half a day.

Can I dry a down duvet at a laundromat?

Yes — and for large duvets (200x220 or 240x220), the laundromat is even the better choice. The large drums offer more space for the duvet to rotate freely. Pay attention to the temperature setting: choose "low" or "gentle," not "hot."

Down duvet smells musty after washing — what to do?

A musty smell after washing is almost always a sign of incomplete drying. Solution: Put the duvet back in the dryer — at least 2 cycles at 50–60 °C with tennis balls. If the smell persists, the moisture was in the duvet for too long and mold has formed. In this case, only professional cleaning will help.

Do I need to wash a new down duvet before first use?

No. BEFA down duvets are hygienically clean after production and ready for immediate use. The down is sterilized at over 100 °C, and the cover fabric is Oeko-Tex Standard 100 certified. We recommend the first wash after 6–12 months of use.