How to Clean a Washing Machine with Soda Crystals

Washing machine smelling musty? A monthly empty hot wash with Soda Crystals clears the greasy build-up where the smell starts.

Takes 10 minutes, plus one empty hot cycle

What you’ll need

300 g Soda Crystals
½ tsp Organic Castile Soap in a bowl of warm water
An old toothbrush
Premium Microfibre Cloth
An old towel and a shallow tray

Method

Pull out the detergent drawer, soak it in the bowl of warm water with ½ tsp Organic Castile Soap and scrub the corners with the toothbrush.
Wipe the rubber door seal with a damp Premium Microfibre Cloth, pulling back the folds: this is where fluff and black mould hide.
Clean the filter, usually behind a small hatch at the bottom front. Put the towel and tray down first, as water will come out.
Put 300 g Soda Crystals straight into the empty drum.
Run the hottest, longest cycle your machine has (60–90°C), with nothing in it.
Leave the door and drawer open afterwards so everything dries.

Use for

Front- and top-loading washing machines that smell musty, leave grey flecks on clothes or have a greasy film in the drum or drawer.

Why it works

The smell comes from a greasy film of detergent, fabric softener and skin oils that builds up in the drum and pipes, especially if you mostly wash cool.

Soda Crystals are strongly alkaline, so in a hot wash they turn that grease into something soapy that rinses away. They also soften the water, which helps the rinse carry everything out.

The science: Sodium carbonate (PubChem, NIH) →

What not to clean with Soda Crystals

Dishwashers: Never put Soda Crystals in a dishwasher. Use our Dishwasher Freshener or Machine Descaler instead.

Aluminium: Soda Crystals darken aluminium. Keep them away from aluminium parts and trims.

With your laundry: This is an empty wash. Don’t add clothes, and don’t add Citric Acid in the same cycle.

Storage and Shelf-Life

Keep Soda Crystals sealed in a cool, dry place. They absorb moisture from the air and turn into a hard lump if left open.

Stored dry, they keep for years.

Safety Precautions

Soda Crystals can irritate skin and eyes. Wear rubber gloves and keep them out of reach of children and pets.

Check your machine’s manual first. If it has its own drum-clean programme, use that with the Soda Crystals in the drum.

B&M Pro-Tip 1:

Alternate each month: Soda Crystals one month for grease and smells, our Machine Descaler with Citric Acid the next for limescale. Never both in the same wash.

B&M Pro-Tip 2:

Leave the door and drawer open after every wash, not just after a deep clean. A machine that dries out between washes rarely gets smelly.

Quick questions

How often should I do it?
Once a month, or every two weeks if you mostly wash at 30°C.

My machine has a drum-clean programme. Can I use that?
Yes. Check your manual, then run that programme with the Soda Crystals in the drum.

Can I do the same in my dishwasher?
No, never put Soda Crystals in a dishwasher. Use our Dishwasher Freshener or Machine Descaler instead.

Try this next: Machine Descaler →