The sandals you lived in all summer are now sitting by the door looking like evidence. Darkened footbeds with the ghost of your toes printed on them, dusty straps, a faint but undeniable smell. Every year people either scrub them into ruin or shove them in a cupboard and buy new ones in May. Neither is necessary.
Cork-and-suede footbed sandals are genuinely repairable, but they hate two things above all: soaking and heat. Almost every horror story — warped footbed, cracked cork, straps gone stiff and pale — comes from water sitting too long or a radiator finishing the job. Work dry-ish and slow and they'll come back remarkably well.
The footbed: dry brushing first, always
Start with a completely dry shoe and a stiff brush — an old toothbrush works, a suede brush is better. Brush the whole footbed briskly in small circles. A surprising amount of what looks like permanent staining is compacted dust and dead skin, and it lifts off before you've introduced a single drop of liquid.
For what's left, mix a little mild soap into a small bowl of warm water and dip the brush so it's damp, not dripping. Work in sections, scrubbing gently along the shape of the footbed, and wipe as you go with a barely damp cloth so you're lifting dirt away rather than pushing it deeper. Keep the water off the cork rim as much as you can.
If there's a lingering smell, sprinkle bicarbonate of soda generously over the dry footbed, leave it overnight, then vacuum or brush it out in the morning. It works better than any spray and doesn't add moisture. Repeat once more if the sandals had a hard summer.
The straps: match the method to the material
Suede or nubuck straps want a dry suede brush and a suede eraser for marks. Brush in one direction to lift the nap, rub the eraser over stubborn spots, then brush again. Resist the urge to wet them; water on suede leaves a tidemark that is far harder to remove than the original mark.
Smooth leather straps can take a cloth wrung out in soapy water, then a proper leather conditioner once fully dry — leather that has been in sun and sweat all summer is thirsty, and conditioning now prevents the cracking that shows up next spring. Synthetic straps are the easy ones: soapy cloth, rinse cloth, dry cloth, done.
The cork rim is where sandals actually die
The sealed cork edge is the part almost everyone neglects, and it's the part that determines whether your sandals last three summers or ten. Once that sealant wears thin, the cork absorbs moisture, dries out and starts to crumble at the edges.
Check the rim in good light for hairline cracks or patches where the finish looks matt and dusty rather than smooth. If it looks dry, apply a thin coat of cork sealer with a small brush or a cotton bud, keeping it off the footbed and the leather, and let it dry fully before the next coat. One or two thin coats beat one thick one. Do this at the end of the season rather than the start and you'll pick the sandals up next year ready to wear.
Drying and storing so next summer is easy
Dry them at room temperature, away from radiators, direct sun and hairdryers — heat is what warps cork and shrinks leather. Stand them upright in an airy spot and give them a full day, longer if you got them properly wet. Stuffing the straps loosely with paper helps them hold their shape.
Store them somewhere dry and out of the sun, not in a sealed plastic box where any residual damp turns into mould. A shoe bag or an open shelf is fine. Before you put them away, take thirty seconds to look at the soles: if the tread is worn smooth in patches, a cobbler can resole them, which is almost always cheaper than replacing a good pair.
Can I put Birkenstocks in the washing machine?
Please don't. The machine soaks the cork, agitates the glued joins and then spins everything at a force these sandals were never built for — the result is usually a warped footbed and separating layers, even if they look fine while wet. Hand cleaning with a damp brush takes about fifteen minutes and is the only method that doesn't gamble with the structure.
Why has my footbed gone dark and shiny?
That's the natural result of skin oils and sweat compressing the suede lining over a season of barefoot wear, and to some extent it's permanent — it's a wear pattern, not dirt. Regular dry brushing lifts the nap and lightens it noticeably, and the discolouration will always fade a little once the sandals dry out and rest. If it bothers you, wearing them occasionally with thin socks in the shoulder seasons genuinely slows it down.
