How long can clothes go between washes? The science behind 'recycling' has been revealed

We all fish something out of the dirty washing pile from time to time - but should we be doing this?

Having to unearth an item of clothing out of our laundry basket and wearing it is something we're all guilty of.

One vigorous shake, a surreptitious little sniff to assess how 'fresh' it is, a little spritz of perfume and no one is ever any the wiser.

Items like t-shirts and (we hope) underwear get a regular wash , but there are others, like bras and jeans which can go weeks without seeing the inside of a washing machine or sink.

It's not always a straightforward case of forgetfulness. Some items require hand washing, or you can't justify running a wash cycle for so few clothes.

While there are variables affecting the state of our clothes (sweaty commutes, spilled drinks and kebab sauce, baby vomit etc) Real Simple's brand-new book has laid out exactly how long is too long for each and every item of clothing to go without a wash.

And according to the magazine "there is a science to what's recyclable and how many times you can do it." Making this more or less official (and bad news for those of us who are into 'recycling').

1. Bras

Admit it, we neglect our bras sometimes

It's easy to neglect bras a lot of the time. Maybe it's because they sometime require washing by hand, or because they're not exposed to the elements as much as other items.

How often? But in fact bras should be washed after three to four wears.

Do you wash your bras after three / four wears?

2. Anything white or silk

No one had cottoned on that it was ages since her shirt had last been washed

Diligent laundry-doers separate their whites and delicates and this sometimes means they can't be washed with the same regularity - or else you end up doing a really small load.

How often? We should in fact be washing whites or silks after EACH wear!

Do you wash your whites and silks after each wear?

3. Pyjamas

The thought of doing a load of laundry did not make her happy

A recent YouGov poll revealed not only should we change our bedding once a week, but we should also pull back the duvet and open a window every morning to get rid of the moisture and humidity.

Many of us will throw our pyjamas in with our bedding - but is this correct?

How often? No! We need to wash our pyjamas after three or four wears, just like our bras.

How often do you wash your pyjamas?

4. T-shirts, vests and camisoles

His t-shirt will definitely need a wash now

How often? It's bad news for those who'll happily recycle these unless there's a good reason to wash them. These items of clothing should be washed after each wear.

Also in this category are underwear (obviously), tights and stockings and swimwear.

Have you ever worn a T-shirt or top twice in a row?

5. Jeans

There are different arguments around jeans

There is more than one school of thought on this matter. The CEO of Levis, Chip Bergh, recently admitted we should NEVER wash our jeans . Instead, we should spot clean stains with a toothbrush and kill of bacteria by putting them in the freezer. And surely he'd know, right?

Then again, Real Simple's take was very different.

How often? The magazine stated we should actually be washing them after four or five wears.

How often do you wash your jeans?

6. Wool coats. hats and scarves

Winter is over, but what do we need to do to our winter wear?

Summer is supposedly here, which means we can put our woollies into storage. But before we pack them away, we ought to give them a bit of TLC.

How often? Coats should we washed (or dry-cleaned) once or twice every season, and our hats, scarves and gloves should be washed three to five times per season.

Do you wash your winter coat every season?

7. Jumpers, fleeces and sweatshirts

The frequency depends on the material

The frequency at which we should be washing our jumpers or fleeces depends on the material.

How often? So, cotton, silk and cashmere should be washed after every second wear.

Our wool and synthetic blend items need to be washed after five wears, and our fleeces after six wears.