The iconic, red-capped plastic soy sauce fish has been a staple of the global sushi experience for over half a century, but its legacy is one of environmental persistence rather than culinary joy. With an estimated 10 billion plastic fish used since 1950, these tiny containers—used for mere seconds—often spend centuries in the ocean, contributing to the global microplastic crisis. In response, Sydney-based studio Heliograf has collaborated with industrial design firm Vert Design to launch “Holy Carp!” on the Dezeen Showroom in late 2025. This home-compostable alternative is crafted from renewable bagasse plant pulp, a byproduct of sugarcane processing. By reimagining the material and the supply chain, Heliograf is turning a symbol of plastic pollution into a champion of circular design, proving that even the smallest objects can drive a massive shift toward a plastic-free future.
Geological Guilt to Biological Grace
The “Holy Carp!” project is the culmination of a five-year mission for Heliograf founders Jeffrey Simpson and Angus Ware. The duo first gained international acclaim with their “Light Soy” lamp, a high-end glass luminaire designed to shine a light on the irony of a fish-shaped object poisoning the marine ecosystem. However, they realized that raising awareness was only the first step; a functional, commercial-scale replacement for the single-use plastic fish was the ultimate goal. The breakthrough came when the designers noticed the protective paper-pulp inserts inside their own lamp boxes, realizing that bagasse (sugarcane pulp) possessed the structural integrity and flexibility needed to mimic the “squeeze” of the original plastic dropper.
Unlike traditional plastic soy fish, which are pre-filled in factories and shipped across the globe, Holy Carp! containers are designed to be filled fresh at the point of sale. This shift in the logistics model is revolutionary; it allows for the use of more sustainable, plastic-free materials that wouldn’t survive long-term storage in a factory but can easily hold liquid for up to 48 hours in a restaurant setting. This “fill-in-store” approach also grants restaurants the freedom to choose their own high-quality sauces, elevating the sushi experience while simultaneously meeting the stringent single-use plastic bans currently sweeping through Australia and the EU.
Functional Anatomy: Engineering the Perfect Squeeze
In collaboration with Vert Design, Heliograf spent months perfecting the 3D form of the bagasse fish. The challenge was to create a material that felt familiar to the user but functioned within the limits of plant-based fibers. The final design features a domed belly, specifically engineered to be squeezed by the diner to release the sauce. The dropper opening is strategically placed just below the fish’s eye, allowing for precise control over the flow—a common complaint with the original plastic version which often “squirted” unpredictably.
Each dropper is slightly larger than the traditional 3ml or 8ml plastic fish, holding up to 12ml of sauce. This design choice was informed by observations that sushi diners often grab three or four plastic fish for a single meal; a larger, single compostable container reduces overall waste and simplifies the dining experience. Internal fill lines allow restaurant staff to provide a “half” or “full” serve, further minimizing the millions of liters of soy sauce that are discarded globally every year.
The Bagasse Revolution: Why Sugarcane Matters
The choice of bagasse as the primary material is a strategic nod to the future of zero-waste packaging. Bagasse is the fibrous residue left over after sugarcane stalks are crushed for juice. It is an abundant agricultural byproduct that requires no extra land or water to produce, making it one of the most sustainable fibers on the planet. For Holy Carp!, Heliograf ensured that the pulp is free from PLA (bioplastic), PFAS (forever chemicals), and other traditional plastic liners that often sneak into “compostable” products.
This commitment to purity means that once the sushi is eaten, the Holy Carp! container can be tossed into a home compost bin or an organics bin, where it will break down into soil-enriching nutrients in just a few weeks. In contrast to the “bioplastic” alternatives that often require industrial composting facilities to degrade, Holy Carp! is truly “homegrown.” It represents a shift from “recycling”—which is often ineffective for small, contaminated plastics—to “regeneration,” where the packaging literally feeds the earth.
Market Readiness: Navigating the 2026 Global Bans
The timing of the Holy Carp! launch is no coincidence. In 2025, South Australia became the first state to officially ban single-use plastic soy sauce fish, with the rest of Australia and several European nations expected to follow suit in 2026. Heliograf has already received hundreds of inquiries from major sushi chains and independent restaurants eager to find a compliant solution that doesn’t sacrifice the “personality” of the original experience. As the state-of-the-art production line readies for a full-scale rollout in early 2026, the Holy Carp! is positioned to become the new global standard for takeaway condiments.
To address concerns about leakage during transport, the designers introduced an optional compostable sticker that can be applied over the fish’s eye. This sticker provides a hermetic seal for “stormy seas” (the bumps of a delivery bike or car), ensuring the soy sauce stays inside until the diner is ready to decant. This blend of high-level industrial design and practical commercial utility is what sets Holy Carp! apart from other sustainable experiments—it is a product designed to work in the real world of high-volume hospitality.
A Small Change with a Tidal Impact
As Heliograf prepares to ship the first commercial batches of Holy Carp! in 2026, the significance of the project extends far beyond the sushi tray. It serves as a blueprint for how other “micro-plastics”—from hotel toiletries to airline condiment packs—can be reimagined using plant-based technology. Angus Ware emphasizes that while a soy fish may seem small, every drop matters in the fight against ocean pollution. “Most of the world is hooked on disposable things that last seconds,” Ware noted in a recent interview. “Holy Carp! is about letting go of the old and embracing a future where design heals rather than harms.”
With its tactile, beige-toned aesthetic and its playful name, Holy Carp! is a rare example of sustainable design that doesn’t feel like a compromise. It preserves the “spark of joy” that the original soy fish provided to millions of children and adults alike, but it removes the shadow of environmental guilt. As it begins to appear in sushi shops from Sydney to San Francisco, Holy Carp! is a reminder that the most impactful innovations are often the ones that are designed to disappear.
