Materials — ReBrew™
Coffee ground fabric is a textile made by carbonising spent coffee grounds into a fine powder, blending that powder into recycled polyester, and spinning the result into yarn.
The carbonised coffee makes the fibre naturally porous, and that porosity is what gives it its quick-drying, moisture-wicking and odour-resisting behaviour. In our ReBrew™ tees, that yarn is knitted against organic cotton — cotton on the outside for softness, coffee-poly on the inside for performance.
The problem
Australia bins 75,000 tonnes of coffee grounds a year.
Or, in the figure RMIT University's engineering researchers published in the Journal of Cleaner Production: 75 million kilograms of ground coffee waste every year, most of it going to landfill. Globally the number is closer to 10 billion kilograms.
Organic waste sounds harmless. It isn't.
When coffee grounds decompose in landfill without oxygen, they release methane — a greenhouse gas roughly 80 times more potent than carbon dioxide over a 20-year timeframe. Landfilled organics also contribute to leachate, the potentially toxic liquid runoff that seeps out of waste sites.
And it's a waste of a good material.
That's the part that gets less airtime. Spent coffee grounds can improve garden soil, exfoliate skin, work as a natural dye, strengthen concrete — and, as it turns out, become clothes. That last one is what we spent the past year working on.
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Grounds are collected from cafés.
Post-consumer coffee grounds are sourced from cafés and food service businesses. These are grounds already headed for the bin — a waste stream, not a crop grown for fibre.
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They're dried, cleaned and milled.
The grounds are dried, cleaned, and milled down into a fine, even powder.
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The powder is carbonised.
Heated to high temperatures to strip out residual oils, odours and impurities. What's left is a naturally porous, deodorising carbon powder — and that porosity is the whole point. It's the structure that later pulls moisture off your skin.
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It replaces a portion of the polyester.
During yarn production the coffee powder is blended directly into recycled polyester chips to form a masterbatch — a concentrated mixture used to dose colour or functional additives precisely into plastics.
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The masterbatch is spun into filaments.
Melted and extruded into continuous filaments.
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Filaments are drawn, then wound into yarn.
Stretched to build tensile strength, then wound onto cones. The output is a yarn that performs like technical polyester while diverting organic waste and displacing a share of virgin synthetic content.
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Then knitted, dyed and finished.
The yarn is knitted with organic cotton, dyed using a low-impact technique compatible with both fibres — one process, not two — then finished to enhance softness, stabilise the knit and lock in the yarn's functionality.
What it does
The porous carbon structure isn't decorative.
It changes how the fabric behaves against skin. Five things follow from it.
Moisture-wicking
- Why
- Porous carbon draws moisture into the fibre structure.
- Feels
- Sweat is pulled off the skin and spread across the fabric instead of pooling.
Quick-drying
- Why
- More surface area means faster evaporation.
- Feels
- Less of that clammy, stuck-to-you feeling by mid-afternoon.
Naturally cooling
- Why
- Evaporation carries heat away from the body.
- Feels
- Cool to the touch, rather than simply not warm.
Odour-resisting
- Why
- The carbonised structure traps odour compounds.
- Feels
- Stays fresher between washes — no chemical treatment involved.
Waste-diverting
- Why
- Coffee grounds replace a portion of virgin polyester.
- Feels
- Nothing, honestly. That's rather the point.
Where it sits
- Layer
- Coffee-poly on the inside of a ReBrew tee, against the skin.
- Because
- The layer doing the work sits where the work happens.
The construction
Why it's two fibres, not one.
An all coffee-polyester tee would wick brilliantly and feel like a gym singlet. That's not what we wanted. ReBrew™ garments are knitted with organic cotton on the outside and coffee-polyester on the inside — 46% organic cotton, 54% coffee-grounds-blended polyester. Cotton's soft hand-feel and natural drape where you can see and touch it; the technical layer where it matters.
Honestly? It's still a blend containing polyester, and blends are harder to recycle at end of life than single-fibre garments. We're not going to pretend otherwise. What the coffee blend does achieve is diverting organic waste from landfill, reducing the virgin synthetic content in the yarn, and — this matters more than it sounds — making a tee you'll actually keep wearing through summer instead of retiring to the bottom of a drawer. The most sustainable garment is still the one you wear the most.
Is it any good in an Australian summer?
This is the fabric's home ground. Humidity is the real test: when the air is already saturated, sweat has nowhere to go, and a fabric that holds moisture rather than moving it will feel heavy by mid-afternoon. The porous coffee-carbon structure works the other way — it pulls moisture off the skin, spreads it across a larger surface area, and lets it evaporate. Evaporation carries heat with it, which is why the fabric reads cool against the body.
Where that shows up most: commuting, when you walk to the tram in 32°C and then sit under air conditioning. Travelling, when quick-drying plus odour-resisting means a sink wash tonight and a wearable tee tomorrow. And back-to-back days, when the odour resistance genuinely extends how long a tee stays fresh between washes — better for the garment, and for your water bill.
The garment
Meet the ReBrew™ Classic T-shirt.
The tee this fabric was built for.
Women's ReBrew™ Classic T-shirt
- Fibre
- 46% organic cotton, 54% coffee-grounds-blended polyester
- Fit
- Versatile and semi-structured — holds its shape without clinging. Size up for a looser, boxier silhouette.
- Colours
- Black, White, Espresso, Sky, Shadow
- Sizes
- S–2XL
Men's ReBrew™ Classic T-shirt
- Fibre
- 46% organic cotton, 54% coffee-grounds-blended polyester
- Fit
- Versatile and semi-structured — holds its shape without clinging. Size up for a looser, boxier silhouette.
- Colours
- Black, White, Espresso, Sky, Shadow
- Sizes
- S–2XL
Questions
The ones we get asked most.
Does a coffee ground t-shirt smell like coffee?
No. Carbonisation removes the oils and aromatic compounds during processing. What's left is odour-absorbing carbon, not coffee scent — the fabric is designed to neutralise smells, not add one.
Is coffee ground fabric actually sustainable?
It diverts post-consumer coffee grounds from landfill, avoiding methane emissions, replaces a portion of virgin polyester with recycled content, and is dyed in a single low-impact process. It's a blend, so end-of-life recycling remains harder than for single-fibre garments — a genuine trade-off, not a solved problem.
Does the coffee wash out?
No. The coffee carbon is embedded within the fibre itself, not applied as a surface coating or finish. The performance lasts as long as the garment does.
Is it good for sensitive skin?
The outer face of a ReBrew tee is organic cotton, with the technical layer sitting inside. The blend contains no added antimicrobial chemical treatments — the odour resistance is structural.
How is it different from bamboo or recycled polyester?
Bamboo viscose is soft and breathable but usually chemically processed. Standard recycled polyester reduces virgin plastic but adds no functional benefit. Coffee ground fabric does both — it uses recycled polyester as the carrier and adds waste-derived carbon that delivers real wicking and odour performance.
Can I wear it in winter?
Yes, though it's built for heat. The moisture management works year-round, which makes it a strong base layer under knitwear.
Care
Five steps, and two of them matter more than you'd think.
Wash it in a full load, and skip the softener. Those two do most of the work.
In short
Your flat white leaves about 20 grams behind.
Multiply that across Australia and you get 75,000 tonnes a year of a material currently generating methane in landfill — when it could be doing something useful. We picked one useful thing: a breezy summer staple that gives used coffee grounds a second life.