I used to think the only decision worth worrying about when it came to denim care was whether I should throw them in a hot or cold wash.

After all, jeans were originally developed to create a hard-wearing, rip-resistant alternative for miners. Surely they’re made of tougher stuff than the weekly wash cycle?

Well, according to the denim experts, you might not have to wash them at all. The designers, founders and creative directors of six top Aussie labels reveal how to make your denim last longer, plus why you need eucalyptus oil in your denim-care arsenal, and whether that longstanding freezer rumour actually works.

If you’ve ever wondered why you have to replace your jeans every two years, read on.

Let’s start with washing – how often should you do it?
Susan Caldwell, head of product at Assembly Label, tells us that the perfect fit comes from minimal washing.

“I’d always advise washing your jeans as few times as possible to encourage natural wear and colour fading. Denim also softens over time with wear, so you’ll find that they start to mould to your body shape in a really organic way. This gives your jeans so much more character and is ultimately kinder on the environment.”

Similarly, Bassike co-founder and creative director Deborah Sams suggests skipping the wash and simply airing your jeans out.

“It’s often better to age a dark indigo jean through wear, not washing – you can just hang them on the line to air out. Washing denim vigorously and often can start to breakdown the fibres and cause your jeans to lose their shape.”

Ultimately, washing is a harsh process that fades denim over time and can affect its fit. Do it as little as possible.

Okay, but when I do need to wash them, what’s the best way to go about it?
Obviously there are times when soap and water is unavoidable (I’m looking at you, spilled milky coffee).

Sarah Gilsenan, co-founder and head womenswear designer at Rolla’s, suggests keeping the wash temperature down for most types of denim. “Cool washing is generally best for denim, along with a gentle detergent and line drying,” she says. Remember to keep your jeans in the shade when line drying, as harsh sunlight can cause colours to fade. But there are a few exceptions to the cool-wash rule.

“100 per cent cotton – or rigid denim – jeans are more robust, so they’re fine in a warm wash and even tumble drying,” says Gilsenan.

“Stretch fabrics, however, will deteriorate over time with hot washing and tumble drying. They’re best cool-to-warm machine washed, then line dried. Tumble drying is not recommended (excess heat breaks down the elastic over time, so they lose their shape and the fabric will eventually tear. Especially on lightweight stretch fabrics.”

Gilsenan adds that you can identify a stretch fabric by looking at the care label. “It’ll be listed as spandex, elastane or lycra, usually blended with cotton.”

Denim that has been bleached or has holes needs extra care too. Wash bleached denim in water only, as fabric softener and detergent can cause yellowing of the bleached sections. Torn jeans are best washed in a delicates bag to prevent further tearing.

Spot cleaning is also a good way to avoid a wash, assuming your jeans are mostly clean.

“Spot a stain with a damp cloth instead of washing,” says Denimsmith director Vinh Le. “Only wash when you really need to.”

Le tackles small stains with a clean, wet cloth (without soap), and sees a full-blown wash as a last resort.

Sara Fletcher, senior wash developer at Nobody Denim, says natural products such as vinegar and eucalyptus oil are great for spot cleaning.

“Apply water directly to the stain, place a blotter [such as a piece of cloth] underneath the spot you’re cleaning, and using a mixture – a bit of a paste – with water and dishwashing detergent together with a touch of white vinegar, apply to the stain using a cotton bud,” Fletcher says. “The blotter on the back should draw out the stain.”

I would recommend creating a, adding just a touch of vinegar, yes white vinegar is good.

Emma Boseley, menswear designer at Neuw Denim, also uses vinegar. “If you must give your jeans a full wash, add a little bit of white vinegar [in with the soap] to help eliminate lingering odours,” she says.

Gilsenan also gets behind eucalyptus oil – she reckons it’s great for oily stains. “Chilli sauce for example: dabbing gently with a tiny bit of eucalyptus oil or a soap like Sard before washing can help lift it.”

What about that freezer trick – does it work?
One of the most contentious denim rumours bouncing about the internet is the idea that you can pop your jeans in the freezer instead of washing them, because the cold will kill any bacteria (negating the need for a wash).

Our denim experts are divided on whether the old freezer trick actually works. Le tells us that airing them out works just as well, while Caldwell believes it’s a myth (there’s a good chance she’s right).

Boseley says that – whether or not the method is effective – any reduction in washing is a positive for the planet. “Washing your denim less helps to reduce water usage and ultimately environmental impacts,” she says. “[And] fewer washes allow your denim to develop their own unique look.”

Many types of bacteria can actually survive freezing temperatures, so that “hack” likely isn’t going to be effective for hygiene purposes.

“The process of freezing your jeans … doesn’t actually ‘freshen’ them,” Fletcher says. “It should help to remove some levels of odour, if there are any, however airing them on a hanger should do the same job.”

What other hacks will help your jeans last longer?
Gilsenan suggests patching worn-out sections, or getting a tailor to mend areas that endure a lot of wear and tear (such as between the thighs).

“Denim is a wonderful, robust fabric but it is not indestructible,” she says. “So I think having realistic expectations of jeans is good … I’d suggest rotating two pairs if you want to wear them every day.”

Fletcher suggests avoiding harsh chemicals such as bleach, even when washing white jeans, which – to that point – are best washed separately.

Caldwell warns against non-natural cleaning products as a whole. “I always advise steering clear of harsh chemicals or stain removers, which can cause the colour to run and bleed,” she says. “Instead, use a natural soap or detergent to spot clean any stains or blemishes.”

The Assembly Label crew are fans of the Ms Brown range of detergents, which are gentle, plant-based and biodegradable.

Caldwell also avoids abrasive cloths or sponges when spot cleaning. “A toothbrush should be all the manpower you need,” she says.

And Boseley recommends storing your jeans in a dark place to minimise damage from sunlight.

Of all the jeans in your wardrobe, which pair has lasted longest?
“My oldest pair are original Navy-issue denim sailor trousers,” says Gilsenan. “They still have all the army numbers stamped inside. They were super-dark crisp rinse blue when I got them. I’ve had them around 20 years. They were the inspiration behind the Rolla’s Sailor Wide Jean.”

Fletcher has two old favourites – both archived styles. The first is Nobody’s Classic Tailored Slung jean, and the second is the Legacy Slung Jean. “I got them five and six years ago,” Fletcher says. “Both are very old styles, but I still love them to death.”

In the end, your jeans will probably outlive most other items in your wardrobe due to their hard-wearing DNA. But with a little extra care, they’ll look great and fit beautifully for years to come.