Your washing machine drawer goes black every autumn: the one cleaning step you keep skipping

First chill in the air, radiators click on, and suddenly your “fresh” wash smells like a wet jumper forgotten in a gym bag. You slide out the detergent drawer and there it is: black, furry gunk clinging to the corners and a sour whiff you can’t quite name.

A mum in Manchester thought her son’s PE kit just “smelled like teenagers”. Then she pulled the drawer right out before a hot wash and saw the problem - a thick black tide mark right along the softener channel, and slimy streaks under the plastic ridge you never see. The wash wasn’t failing. The drawer was.

We’ve all had that moment when you’re shoving in another load, see the grey ring around the tray, and promise yourself you’ll “properly clean it this weekend”. Autumn comes, the house is steamy, and the mould blooms faster than you can keep up. The thing you’re skipping is not elbow grease. It’s the rinse.

The hidden reason it goes black when the heating comes on

Modern machines don’t actually flush the drawer clean. They send quick spurts of water through narrow channels, just enough to pull powder and softener into the drum. The rest - thick liquids, fabric softener slime, undissolved pods, stray lint - clings to the plastic and sits there in the dark.

Autumn turns that drawer into a little greenhouse. Warm kitchen, cool outside wall, damp detergent film, and the drawer front closed most of the day. Condensation forms on the underside and trickles back into the channels. Spores love it. Within weeks you get black mould along the seams, orange biofilm in the softener well, and a smell that hops from drawer to towels.

The skip-habit is simple: we clean the tray but not the waterways. People pull the drawer, give the main compartments a scrub, then slide it back in without ever flushing the cavity above or the spray holes that feed it. So the next cycle, water carries old mould straight onto your fresh drawer and into your wash.

The physics is boring but brutal. Sticky surfactants + trapped lint + warmth + no airflow = a petri dish. You don’t need a new machine. You need a rinse route for somewhere the eye doesn’t normally go.

The one extra step pros swear by (and it takes 90 seconds)

Appliance engineers are quietly united on this: treating the drawer housing like a mini filter stops the black tide. Not once a year. Once a week, in the time it takes the kettle to boil.

The move is this: you always rinse the drawer cavity and spray bar after you clean the tray. Not just the visible bit.

Here’s the exact routine many repair techs recommend:

1. Pull the drawer fully out. Most have a little blue tab or clip in the softener section; press it and slide the unit free.
2. Soak and scrub the tray. Warm water, a squeeze of washing-up liquid, and an old toothbrush for seams. Lift out any removable inserts.
3. Now, clean the cavity:
   • Fill a jug with very hot (not boiling) water and a splash of white vinegar.
   • Pour slowly into the back corners of the housing where the water normally comes in.
   • Catch the run-off in a towel or tray at the bottom of the machine front if it drips.
4. Wipe the rails and roof. Use a microfibre or sponge cloth wrapped round two fingers to reach the top and sides. Black spots mean mould; orange means softener slime.
5. Poke the spray holes. If your model has a removable spray bar above the drawer, unclip it and rinse it under the tap, using a cocktail stick or cotton bud to clear limescale from each hole.
6. Dry before reassembling. Shake off excess water, towel the cavity edges, and leave the drawer itself to air-dry for 20 minutes before sliding back.

One engineer I spoke to in Leeds said customers’ odour complaints halved when they started doing this just once a week in autumn and winter. No expensive cleaners, no “drum refresh” programme every day. Just heat, flow and no sludge.

Let’s be honest: no one does a full strip-down after every wash. This is the low-friction version that actually fits into a Tuesday night.

How to stop the black mould coming back

Once you’ve done the deep clean and rinse, changing a few tiny habits keeps the drawer clear for much longer.

• Ditch the drawer for some loads. Use detergent capsules directly in the drum for towels and bedding so the drawer gets regular “rest days”.
• Go easy on softener. Overfilling the line is the fastest way to get that thick, sweet-smelling sludge. Stay below the max mark, or switch to white vinegar in the softener compartment for some cycles.
• Leave the drawer ajar. After each wash, pull it out an inch so the cavity and tray can dry. Airflow is your cheapest anti-mould treatment.
• Run a hot maintenance cycle monthly. Empty machine, hottest cotton setting, with a cup of soda crystals or washing machine cleaner in the main wash. It won’t reach the drawer gunk, but it will hammer what’s already washed into the system.
• Watch what you pour. Skip thick, concentrated liquids that cling to plastic when you’re already battling black slime. If you love them, pre-dilute with warm water in a jug before tipping in.

One more pro move: if your water is hard, limescale will roughen the inside of the housing and give mould somewhere to grip. Wiping the cavity roof with a vinegar-soaked cloth once a fortnight keeps it smooth so muck can’t hang on.

“It’s not the drum that’s dirty nine times out of ten,” one repair tech told me. “It’s the parts that never see daylight. Rinse those, and the smell usually walks out with it.”

• After every wash: leave the drawer slightly open.
• Once a week in autumn: quick cavity rinse with hot water + splash of vinegar.
• Once a month: hot maintenance cycle for the whole machine.

The small change that makes laundry smell clean again

When the drawer stays clear, everything downstream behaves better. Towels stop coming out with that dull, “used once already” smell. Whites stay brighter because grey, mouldy rinse water isn’t being fed back in during the final stage. The rubber door seal often stays cleaner, because there’s less biofilm sluicing through.

You also drop the risk of black mould spores blowing into the laundry area every time you yank the drawer open. For allergy-prone households, that matters as much as the scent.

Most of all, the machine feels trustworthy again. You stop throwing money at ever-stronger perfumes to mask a smell that’s actually structural. A jug of hot water, a cloth, and ninety seconds in front of the drawer door quietly fix what a dozen “odour defence” products keep trying to perfume away.

Share this with the person in your house who always shoves the drawer shut with their hip. The next time you see that black tide line creep in, you’ll know exactly where to pour, wipe and walk off.

Key step	What you actually do	Why it matters
Rinse the cavity	Jug of hot water + vinegar into drawer housing and spray bar	Flushes hidden slime and spores, not just the visible tray
Air the drawer	Leave it open a crack between washes	Cuts condensation and starves mould of constant damp
Limit sludge	Use less softener, pre-dilute thick liquids	Reduces the sticky film mould feeds on

FAQ:

• Is the black stuff in the drawer dangerous? It’s usually mould and bacterial biofilm. It’s unpleasant and can aggravate allergies and asthma, so it’s worth removing and preventing, even if it’s not instantly “toxic”.
• Can I just use bleach to solve it? A diluted bleach wipe will kill surface mould, but without rinsing the cavity and spray bar, the gunk returns. Bleach can also damage rubber if overused, so keep it occasional and always rinse well.
• What if my drawer doesn’t seem to come out? Most do, but the release catch can be hidden. Check the manual or look for a clip in the softener section. If it truly doesn’t remove, focus on hot-water flushing and long-handled brushes.
• Does a washer–dryer combo get worse? Often yes, because the machine runs hotter and longer, increasing condensation. The same cavity-rinse routine still works; you may just want to do it a bit more often in winter.
• Will this fix a machine that already smells awful? It usually helps a lot, but if the drum seal and filter are also caked, you’ll need to clean those too. Think of the drawer rinse as one crucial part of a full reset, not a magic wand.