“Most people have no idea there’s plastic in their tea bag. Or in their coffee filter.” – Why a 76-year-old Bendigo potter is selling his last ceramic filters at a special price

For two winters, Darcy Pengilly fired filter after filter in his Bendigo workshop until he had one that holds back the tea leaves with nothing but ceramic. Now arthritis has taken his hands, and the last 167 sets are going out before his studio closes on 30 November.

Every afternoon for over forty years, Raelene Pengilly did the same thing. She dropped two tea bags in the brown pot, poured the water straight off the boil and sat down with her cuppa on the back verandah. In the morning she made coffee, a little plastic cone on her mug with a paper filter folded into it. Her husband Darcy never thought twice about either. Neither did anybody else in their kitchen.

Then, one summer evening in early 2023, their granddaughter Kirra came in from turning the compost heap with a handful of something and said a sentence that changed the last years of Darcy’s working life.

“Pop, why are Nan’s tea bags still in the compost?”

Darcy is 76. He has been making pottery in Bendigo, Victoria, since he was eighteen, in a city that is home to the oldest working pottery in Australia and has been firing kilns since 1858. He knows what happens to materials in heat better than almost anyone. And what Kirra showed him that night bothered him enough to spend two winters solving it.

The Plastic Nobody Mentions

The tea in those bags had long rotted away. The bags themselves were still there, months later, little pale pouches that wouldn’t break down. Most people think of a tea bag as paper and a coffee filter as paper. Neither is quite true.

Many tea bags are sealed with polypropylene, a plastic that keeps the bag from falling apart in boiling water. The “silky” pyramid bags are often nylon or PET outright. And the newer “plant-based” bags are mostly PLA, which the British consumer group Which? put plainly: it is “still a type of plastic.” PLA only breaks down in an industrial composting plant, not in a backyard heap. In a 2019 lab study at McGill University, a single plastic tea bag steeped at brewing temperature released billions of micro- and nanoplastic particles into the cup.

Paper coffee filters have the same problem in a quieter form. Plain paper turns to mush in hot water, so most filters are made with plastic-based resins that hold the fibres together while you pour water just off the boil through them. It says nothing about that on the box.

And then there are PFAS, the so-called forever chemicals. They are used to help paper and packaging stand up to water and grease, and an independent lab test found PFAS markers in a popular brand of paper coffee filters. Most people have never heard the word in connection with their cuppa or their morning coffee.

“That’s what got me,” Darcy says. “Not that it’s there. That nobody tells you. You pour water at near enough a hundred degrees through it every day of your life and you don’t even know what it’s made of.”

Kirra did the sums for her nan: three cuppas and two coffees a day, for forty-odd years. That is somewhere around seventy thousand bags and filters. Every one of them used once, chucked out, and bought again.

What His Pop Kept on the Bench

Darcy didn’t need a laboratory to find the answer. He needed to remember his grandfather’s kitchen.

His great-grandfather came out from Cornwall to dig for gold, and the family stayed in a miner’s cottage in Eaglehawk. On the kitchen bench stood a tall stoneware water filter with a little brass tap at the bottom. Inside was a fired ceramic filter. Tank water went in at the top, seeped through the stone-hard walls and came out clean at the bottom. Nobody ever replaced it. It had been there before Darcy was born.

He was right about the history. Henry Doulton built porous ceramic water filters in London from 1827, and Queen Victoria had one at Balmoral. Stoneware filters like them stood in Australian kitchens for generations. The paper coffee filter wasn’t invented until 1908, and the tea bag only took over from the pot of loose leaf in the second half of the twentieth century. For most of history, the thing between you and your drink was something you kept for life.

Two Winters and 300 Firings

“If water can run through ceramic,” Darcy told Kirra, “so can a cup of tea.” Getting there took two winters, after the regular pottery orders were done.

The hard part was the pores. Too coarse, and the leaves and dust came through and the cup tasted of sludge. Too tight, and the water sat on top and went cold. Darcy mixed a fine ceramic body, pressed each filter by hand into a small cone, let it dry and fired it hot enough to turn it stone-hard without closing it up. He left it unglazed on purpose. A glaze would seal the pores shut.

The minerals in the mix and the heat of the kiln turn every filter the same deep charcoal grey. Inside, it feels like fine stone. Through the walls run thousands of pores far smaller than a tea leaf or a grain of coffee.

He went through more than 300 firings before he made one he would sell. Raelene was his tester. Every afternoon she got a new filter on her cup, and every afternoon she told him what was wrong with it. “She was harder on those filters than any customer,” Darcy says. “When she stopped complaining, I knew I had it.”

The Filter Is the Ceramic

This is the part people misunderstand. Plenty of shops sell a ceramic cone that still needs a paper filter or a tea bag inside. Darcy’s doesn’t. The ceramic itself is the filter. There is no paper, no metal mesh, no plastic ring, nothing to replace.

• Nothing but fired ceramic. No paper, no plastic, no glue, no mesh. Hot water touches ceramic and tea, nothing else.
• Fine pores, clean cup. The leaves stay in the filter. What reaches the cup is tea, not bits.
• Made for one perfect cup. At 8.5 centimetres across and 5.3 centimetres tall, it sits right on top of most standard mugs and holds a heaped teaspoon of loose leaf or about two tablespoons (12 g) of coffee. Darcy never made a pot-sized one. “Nobody needs a whole pot just for themselves,” he says.
• Two in every set. One for your morning coffee, one for your arvo cuppa, so neither picks up the taste of the other. Or one in use while the other dries.

How It Works

Darcy built it to be no more work than a tea bag, and Raelene held him to that.

Afterwards you tap the leaves or grounds onto the compost, where this time everything actually breaks down, and rinse the filter under the hot tap. No detergent: ceramic soaks it up, and you would taste it in the next cup. Every couple of weeks, Darcy boils his for ten minutes in a pot of water with a spoonful of bicarb soda. That keeps the pores open, and it is the whole secret to a filter that stays fast for years.

“I’ve Binned Every Infuser I’ve Ever Bought”

Bronwyn Tait has run a tea shop and café in Castlemaine for 22 years, and she has heard every promise a reusable infuser can make. “Metal infusers let the fine bits through and leave that gritty bottom in the cup,” she says. “Cloth tea socks start to smell. I’ve binned the lot and gone back to paper.”

Kirra sent her two of her grandfather’s filters. Bronwyn brewed the same Assam through a bag and through the ceramic, side by side, then did the same with the café’s house coffee. “I expected bits,” she says. “I got a clean cup. No leaves, no metal taste, no papery taste either. I kept one by my own kettle.”

Here is how it compares with what most kitchens already use:

Coffee in the Morning, a Cuppa in the Arvo

Raelene still drinks both, and that is why every set has two filters. One stays the tea filter: a heaped teaspoon of loose leaf in the ceramic, hot water over it, and a few minutes later a clear cuppa with not a single leaf floating in it. No bag, no string, no little paper tag. The other is her coffee filter, two tablespoons of grounds on her mug first thing in the morning.

“She hasn’t bought a box of tea bags or a pack of filters in two years,” Darcy says. “That was the whole idea.”

Why the Last Ones Are Half Price

Darcy pressed and fired every filter himself, a few dozen at a time, the same way he has made his pottery for 58 years. Since spring 2024, about 1,300 sets have gone out, first from the shelf in his shed and then by post once Kirra started taking orders online.

This winter the arthritis in his hands got bad enough that he couldn’t press the cones evenly anymore. “If the wall isn’t even, the water finds the thin spot and runs straight through,” he says. “Some mornings now I can’t close my hand. I won’t send out a filter I can’t stand behind.”

So the studio closes on 30 November. Kirra, 20, who packs every order, counted what is left: 167 finished sets, each one tested with a cuppa before it went in the box. There won’t be more.

What the First Owners Say

The Questions Readers Keep Asking

“Fifty-eight years I’ve made things people keep. I reckon these two filters will outlast every box of tea bags you’d have bought.”
Darcy Pengilly, Pengilly Pottery, Bendigo, Victoria