You pull your good leather shoes or winter boots out of the cupboard after six months and there is a grey-white, powdery bloom across them. Often you smell it before you see it: that cellar smell. That is mould, and it almost always comes down to one thing, which is a shoe that was put away while there was still moisture in it.
We build machines that dry and freshen footwear from the inside, so we see this a lot. The good news is that most pairs are salvageable. Here is what to do, in what order, and what to avoid.
Why mould grows in shoes
Mould needs three things: moisture, food and stillness. A stored shoe offers all three.
- š Moisture. Sweat in the lining, rain that soaked into the leather, or a damp cupboard, cellar, loft or garage.
- š Food. Leather, suede, textile, adhesive and skin flakes are organic material, which means dinner.
- š Stillness and dark. Inside a closed box nothing moves for months and no air passes through.
That is why it happens to the pair you do not wear for a season: smart shoes, boots, football boots after the season, walking shoes after the summer. Trainers you wear every week rarely go mouldy.
White or grey powdery patches are usually mould. Green or black staining that does not brush off has gone deeper. There is one lookalike worth knowing: salt bloom from adhesive or road salt is gritty, wipes off with a damp cloth and has no smell.
Before you start
Do this outdoors or at an open window, not over the bathroom sink. You will disturb spores, and you do not want them circulating in the house or in your lungs.
- š Wear gloves, and a mask if you have a sensitive chest.
- š Take out the laces and the insoles and treat those separately.
- š Work over newspaper or a bin bag you throw away afterwards.
The steps
Step 1: dry them first. It sounds backwards, but wet mould just smears. Let the shoe dry properly, ideally with airflow from the inside, and clean afterwards. A shoe dryer is made for exactly this; a day in an airy spot also works, only slower.
Step 2: brush it off dry. Take a soft brush to the bloom outdoors, working with the wind, and knock the brush out outside when you are done.
Step 3: clean by material.
| Material | What to use | Watch out for |
|---|---|---|
| Smooth leather | Cloth with lukewarm water and mild soap, or a leather cleaner, then a leather conditioner | Do not soak it; leather needs feeding after a clean |
| Suede and nubuck | Dry suede brush plus a suede eraser, and a suede cleaner only for stubborn patches | Water leaves tidemarks, so work as dry as you can |
| Textile and canvas trainers | Hand-warm soapy water and a soft brush, or carefully in the washing machine | Never a hot cycle, the glue lets go |
| Rubber and soles | Soapy water and an old toothbrush for the seams | Seams are where it returns from |
| Insoles | Wash them or replace them | Badly affected insoles cost a couple of euro, bin them |
| Laces | 40 to 60 degree wash, or new ones | The cheapest part of the shoe, do not be thrifty |
Step 4: treat the inside. The outside is cosmetic, the lining is the problem. Our guide to disinfecting shoes goes into detail: use a shoe disinfectant spray designed for footwear and textiles, let it soak in, then dry completely. Ask a pharmacist or shoe shop for a product meant for the job.
Step 5: dry completely. Every wet treatment has to end in genuinely dry. This is the step people skip, and it is exactly why mould comes back. Allow an hour or a few with warm circulating air, or one to two days somewhere airy. Not on a radiator, not in direct sun, not in the tumble dryer.
Step 6: check the smell. If it still smells of cellar once dry, there is material left in the lining. Repeat steps 4 and 5 once. If it survives two rounds, that pair has had a good life.
What not to do
- š No bleach. It attacks leather and stitching, discolours textile, and it does not belong on something your skin touches.
- š No boiling water or hot wash cycles. Adhesive fails and the shoe loses its shape.
- š Not in the tumble dryer. Tumbling wrecks the heel counter and the midsole.
- š Do not bake them in the sun. Leather goes hard and brittle and colours fade.
- š Do not put them straight back in the box. The most common mistake: stored clean, but still slightly damp.
- š Do not trust UV gadgets. Cheap units with blue LEDs do nothing to micro-organisms, and real UV-C is a genuine risk to eyes and skin at home. Warm air and circulation are the safe route here.
Preventing mould: how to store shoes
The real work is in the storing. We see this pattern every spring with winter boots and every summer with football boots.
- š Never store a damp shoe. If you are not wearing it tomorrow, dry it today. A pair soaked by rain needs to be dry before it goes anywhere.
- š Pick a dry place. A cellar, garage or unheated loft is usually damper than you think. Inside the house is better.
- š Let air reach them. A cardboard box or a cotton bag beats a sealed plastic crate or bag.
- š Use cedar shoe trees or paper stuffing. It holds the shape and takes up residual moisture. Swap the paper after a few days.
- š Air them once a season. A couple of hours outside at the start of the season tells you whether something is wrong.
- š Rotate your everyday pairs. A pair that gets a day to dry does not go mouldy and keeps its looks for longer.
What we use for it
| What | What it does | Price |
|---|---|---|
| Shoefresh Opod | Dries shoes from the inside with warm air and circulation, with programmes per shoe type and a heel dryer | 129 euro (black 139 euro) |
| Opod Detect | Same principle, measures humidity and stops automatically when the shoe is dry | 179 euro |
| Opod Mini | For boots, ski and snowboard boots, helmets and gloves, which is exactly the seasonal kit that goes mouldy | 79 euro |
| Shoefresh Perfume | Adds a fresh scent, and is not a solution for moisture or mould | 24,95 euro |
On a tighter budget, the ShoeDry Airo (around 50 euro) dries with an ioniser, but has no programmes per shoe type, no heel dryer and no automatic start.
Frequently asked questions
Can you still wear mouldy shoes? If you have cleaned them, treated the inside and dried them completely, yes. For a soaked pair where the mould has reached the midsole and the cellar smell survives two rounds, replacing them is the sensible call.
Is mould in shoes dangerous? For most people it is mainly unpleasant and it causes smell or skin irritation. If you have a respiratory condition, an allergy, diabetes or a weakened immune system, be stricter and speak to your GP if in doubt.
Can mould in shoes cause athlete's foot? They are not always the same organisms, but a shoe that grows mould is exactly the warm, damp environment athlete's foot thrives in. Fix the moisture and you address both.
Does vinegar get rid of mould in shoes? Diluted vinegar comes up a lot and it does take the edge off the smell, but it is not a disinfectant for the lining and it leaves moisture of its own. Use a product intended for footwear, and always finish with a full dry.
Why do only my winter shoes go mouldy? Because they sit unused in a cupboard for months, usually stored at the end of a wet season. That is the exact combination of moisture, food and stillness.
Can a washing machine get mould out of trainers? For textile trainers a careful cycle helps, but no warmer and not without a wash bag. Read the approach in our article on shoes in the washing machine first.
Dry shoes do not go mouldy. That is really the whole story. Ready for a fresh start!