Heliograf launches plastic-free alternative to single-use soy sauce fish

Holy Carp! packaging by Heliograf and Vert Design

Australian studio Heliograf has worked with Vert Design to produce Holy Carp! – a plastic-free, compostable alternative to the fish-shaped soy sauce packaging immortalised in its Light Soy lamp.

The Holy Carp! packaging is made of bagasse pulp, a fibrous by-product of sugar production, and was designed to be used by the same restaurants that may have once offered the plastic packets with their takeaway sushi.

Just like with the plastic packaging, Holy Carp! can be used as a dropper, allowing diners to squeeze the fish's "belly" to squirt small amounts of soy sauce on their food.

Photo of a classic plastic soy sauce fish next to the bigger bagasse pulp compostable packaging by Heliograf and Vert Design — Holy Carp! is a plastic-free alternative to the classic fish-shaped soy sauce packaging

The Holy Carp! project follows on from Heliograf's Light Soy lamp, a giant version of the iconic soy sauce fish that was intended as both a loving homage and an awareness-raising exercise about its problems.

The single-use plastic packaging is too small for recycling and so often ends up in landfill or, worse, in the oceans, where it can be mistaken for food by birds and marine life.

Photo of the top and bottom of the compostable soy-sauce plant pulp packaging seperated — The packaging is made of bagasse pulp and is compostable

"We created our recycled ocean-bound plastic lamps to highlight the big problem with the small, seemingly insignificant single-use soy fish and make a difference," Heliograf co-founder Angus Ware told Dezeen.

"The lamps fund plastic clean-ups and hopefully inspire change in the way we design and use everyday objects, but we always felt we could do more. We have wanted to not just talk about and foreground the problem, but actually offer a real solution to single-use plastic soy sauce 'fish' and sachets."

Having had the idea to adapt paper-pulp sauce containers for this purpose, Heliograf approached Vert Design, its collaborator on Light Soy and creator of the lamp's plant-pulp packaging.

Photo of Holy Carp! compostable soy sauce packaging next to a bottle of soy sauce on a restaurant table by a window — It is designed to be filled at restaurants

Using Heliograf's fish graphic, Vert Design worked to give it a 3D form that was highly functional and easy to manufacture, and that would make its recognisable shape an integral part of the design.

The bagasse-pulp fish has a diaphragmatic shape that allows it to function as a dropper when squeezed, with a slight doming of the belly area, just like in the plastic equivalent.

The tail fin becomes a grip to help with easy opening, while a flanged edge creates a leak-proof seal, and the tiny dropper hole below the fish's eye can be optionally closed with a compostable sticker to prevent spills.

Unlike with the plastic fish, which are pre-filled in factories, the Holy Carp! fish are designed to be filled fresh at the restaurant and used soon after, with Heliograf and Vert Design advising that the packaging retains its integrity for 48 hours.

Photo of a hand holding a fish-shaped beige-coloured plant-pulp packaging design in the shape of a fish with a small red circular sticker stuck on it — The dropper opening can be covered with a compostable sticker

With a 12-millimetre capacity, Holy Carp! is larger than the plastic fish, both for ease of use and manufacturing, and to account for the fact that customers often grabbed the old packets by the handful.

The packaging formula involves mixing bagasse fibres with a food-safe wax that eliminates the need for any lining, which would often be made of plastic or PFAS, and the product is expected to break down in four to six weeks in normal home composting conditions.

Photo of a hand holding the Holy Carp! fish packaging and squeezing it upside down so small droplets of soy sauce come out — The fish has a domed belly that diners can squeeze

Vert Design said that it wanted Holy Carp! to keep alive the memory of its characterful plastic predecessor, which is now being phased out in many places and has been outright banned in the state of South Australia.

The plastic fish packaging was invented in 1950s Japan to replace glass or ceramic soy sauce bottles and spread all over the world.

Close-up photo of a small plant-pulp cup being filled by a kikkoman soy sauce bottle — The packaging should be available from early 2026

"From an Australian perspective, discarding such a playful and familiar piece of packaging would be a loss," said Vert Design founder Andrew Simpson. "As a staple of takeaway sushi, it also carries significance within the Japanese diaspora."

"The aim was to create a sustainable alternative that preserves the essence of this familiar experience while honouring its traditional roots."

Heliograf estimates that between 8 and 12 billion soy-sauce fish have been used since 1950. According to Ware, the company has received hundreds of enquiries about Holy Carp! since revealing the design in October and expects to make the product available to restaurants in early 2026.

The photography is courtesy of Heliograf.

Earlier this year, we rounded up 10 alternatives to single-use petroleum-based plastic for the food industry.

The post Heliograf launches plastic-free alternative to single-use soy sauce fish appeared first on Dezeen.