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Can you ever tumble-dry woollen jumpers without shrinking them?
We’ve all been there – you throw a pile of wet laundry into the dryer, not really stopping to think about it, and an hour later your favourite woolly jumper is ruined.
Wool and heat aren't the best of friends, but with the development of 'no shrinkage guarantee' tumble dryers and 'dryer-safe' wool jumpers, surely there's a way to tumble-dry a woollen jumper without shrinking it?
To find out, we tested six different tumble dryers, including a Woolmark-certified AEG model with a ‘no shrinkage guarantee’ that ‘ensures wool won’t shrink’, using a dryer-safe wool jumper.
Read on for the results of our testing, plus handy tips on how to stop your clothes from shrinking.
Best tumble dryers 2023 – discover which models have soared through our rigorous lab tests
How we tested tumble dryer shrinkage
As well as the AEG ‘no shrinkage guarantee’ tumble dryer, we also tested models from Beko, Haier, Hoover, Indesit and LG. All of them are heat-pump tumble dryers, with the exception of the Hoover model, which is a condenser dryer.
All of the tumble dryers were tested with the same dryer-safe women’s size 16 merino wool jumper. Each jumper was washed in the same washing machine and then two jumpers were dried in each dryer. We also washed one jumper by hand and let it dry flat for comparison.
Before testing, we measured the arms, across the chest, from collar to hem and across the bottom. We measured again after testing.
Results: Did the jumpers shrink?
Of the six tumble dryers that we put to the test, only one did a satisfactory job – five of them shrank the jumpers by more than 5cm in at least three areas.
Here's an overview of the results:
| Tumble dryer | Number of areas that experienced shrinkage of 5cm or more | Summary |
| LG FDM309W (£749) | 1 | The only dryer to do a satisfactory job in our tests, with just one 5cm area of shrinkage out of the 10 measurements taken. |
| AEG TR818P4B (£999) | 3 | The Woolmark-approved, no-shrinkage guarantee AEG dried the jumpers at 65℃, which is pretty warm for wool. Across the 10 measurements, three had shrunk by more than 5cm. The chest shrunk by 7cm on one jumper. |
| Beko B3T4924DW | 3 | The Beko shrank three areas of the jumpers by more than 5cm, including the chest by 7.5cm – that’s 13%. |
| Indesit YTM1183XUK (£469) | 3 | Three measurements for jumpers dried in the Indesit were more than 5cm smaller after drying – the chest of one was 7cm smaller. |
| Hoover H-Dry 300 HLEC8TG (£279) | 10 | This Hoover tumble dryer pretty much destroyed both jumpers. That's no surprise when you see that the temperature was 80°C in the drum. All 10 measurements were at least 5cm smaller after drying – one arm was nearly 11cm shorter at the end. |
| Haier HD90-A3Q979U1 (£649) | K.A. | This Haier machine hardly shrunk the jumpers at all, but it hadn’t actually dried them, either. |
Browse all of our tumble dryer reviews to see which models will keep your clothes looking their best.
What the manufacturers told us
AEG told us: ‘Without full details of the testing procedures, which can have an impact on the outcomes of washing, we’re unable to provide comment on the test carried out by Which?. All claims made related to our appliances are following rigorous testing by our R&D and Quality team. We’re confident in the washing and drying capabilities of our machines.’
Beko said: ‘All Beko products are tested rigorously to ensure that our appliances offer reliable performance for our consumers. When testing our wool programme, we found that the shrinkage ratio of wool was less than 1.5%. This is equivalent to 0.5cm shrinkage on 40cm length wool jumpers when testing on two identical samples.’
Haier declined to comment.
Indesit, Hoover and Woolmark hadn’t provided a comment when we published this article.
FAQs: Using a tumble dryer
How should you dry a woollen jumper?
Our tumble dryer shrinkage test results tell us that your best bet is to dry woollens by hand. Gently squeeze out excess water and avoid wringing or twisting the jumper, as this could damage the fibres.
The hand-washed and flat-dried jumper included in our experiment had some minor shrinkage and stretching, but nothing major and no areas shrank by 5cm.
You could try drying your wool jumper on a heated clothes airer. With surface temperatures of around 40-50°C, they are warm enough to dry wool without damaging the fibres, but it's still important to dry the garment as flat as possible to avoid stretching.
Read our guide to the best and cheapest way to dry clothes indoors.
Are there any tumble dryers that don't shrink clothes?
In our test, only one dryer (the LG FDM309W) did a good all-round job of drying wool jumpers without drastically shrinking them.
Our general advice is to avoid using a tumble dryer when drying wool because the temperatures reached in the drum are simply too high. This is especially true of vented or condenser tumble dryers, where drum temperatures will be significantly higher than with heat-pump machines.
Does an anti-shrink tumble dryer exist?
When it comes to wool, an anti-shrink tumble dryer doesn’t exist in the conventional sense of using hot air to dry clothes.
Our tests show that every now and then a dryer comes along that can gently dry woollens without shrinking them, but they’re few and far between.
If you can set your dryer to dry using cold air, woolly clothes in the drum are less likely to shrink or get damaged. But you might find that it will take forever to get your woollens dry.
If you're looking to keep annual running costs low, consult our guide on the best energy-efficient tumble dryers.
How to stop clothes from shrinking in a tumble dryer
Read the label. This will let you know whether your clothes can be dried in a tumble dryer.
- A square with a circle inside means that the clothes can be dried in a tumble dryer.
- If there’s a dot inside the circle, this means that you can use your dryer, but only on a low heat.
- Three dots in the circle means that you can dry your clothes on a high heat.
The other option is to air-dry anything you’re worried about. This worked well in our test and, with clothes you really care about, this will be your safest bet. It might take longer, but for the sake of peace of mind – nobody wants to shrink their best shirt – it’s probably worth it. And it costs nothing to hang your drying clothes over an airer or on the washing line.
Decode the confusing symbols on clothes labels with our guide: Washing symbols explained
Can shrinkage be reversed?
Once a woollen garment has shrunk in your dryer, it's very hard to reverse the effect. Heat from the tumble dryer causes the fibres to interlock, making the fabric tighter and smaller.
We've heard of a 'hack' that involves soaking the garment in warm water and hair conditioner to relax the fibers, but ultimately your best bet is to contact a local tailor or dry cleaner for advice.
Popular tumble dryers
Based on visits to our expert product reviews over the past 12 months, we've picked out a selection of popular, in-stock tumble dryers below. We'd always recommend reading our reviews first though, so you can get the best model for your needs.
- The Indesit YT M11 82 X UK (typical price £409) is a freestanding model that uses a heat pump to recycle hot air from the drum. You get the usual cottons and synthetics cycles, plus a 45-minute Xpress setting and programs for eco drying, mixed loads, ‘mini’ loads and duvets.
- The Bosch WQG24509GB (typical price £768) has a roomy 9kg-capacity drum and dedicated drying options for down-filled jackets, sportswear, towels and woollens. You can also try the 40-minute quick-dry program for smaller loads.
- The AEG TR959M6BC (typical price £1,300) is a smartphone-compatible tumble dryer that lets you check the progress of a wash from your mobile. It also has a built-in delay timer, so you can dry your clothes when it's convenient.
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