Plastic-Free Soy Sauce Fish Dropper Designed to Decompose in Weeks, Not Years

Rethinking Single-Use Objects with a Plastic-Free Soy Sauce Fish Dropper

Single-use food packaging is often designed for moments but persists for decades. The plastic-free soy sauce fish dropper created by Heliograf and Vert Design challenges this imbalance by aligning material lifespan with actual use. Named Holy Carp!, the small container replaces the iconic plastic soy sauce fish with a biodegradable alternative that decomposes in soil within weeks instead of years.

Designed specifically for sushi restaurants, the project demonstrates how thoughtful product design can significantly reduce waste without disrupting familiar rituals of use.

Made from bagasse, the fibrous by-product of sugar production, combined with other plant-based fibers, the plastic-free soy sauce fish dropper breaks down naturally in soil in approximately four to six weeks. No plastic, synthetic coatings, or long-lasting additives are involved. The object is intentionally temporary: it is designed to safely hold liquid for up to 48 hours, reinforcing the idea that a disposable product should not outlive its purpose.

Visually, the container maintains the familiar fish shape, preserving the cultural reference that customers immediately recognize. Functionally, users gently squeeze the dropper—ideally at its center—to release the sauce. A small opening positioned just below the fish’s eye allows controlled pouring, preventing spills while keeping the interaction intuitive.

One key departure from traditional plastic droppers is the filling process. Instead of being pre-filled in factories, restaurants fill the plastic-free soy sauce fish dropper on-site, ensuring fresher sauces and allowing flexibility beyond soy—such as tamari, ponzu, or other condiments. This local filling approach reduces industrial processing while giving restaurants more control over quality and customization.

Designing Against Overconsumption

The Holy Carp! container is deliberately larger than standard plastic versions. This design decision responds to a common behavior observed in restaurants: customers often take more than one small plastic fish, even when a single serving would suffice. By increasing capacity, the design discourages unnecessary duplication, directly reducing overall material use and waste generation.

Throughout development, Heliograf and Vert Design collaborated closely with sushi restaurants, gathering feedback on storage, filling, sealing, handling, and service speed. This hands-on testing ensured the final product integrates smoothly into real-world restaurant workflows.

Material Knowledge as a Design Advantage

The choice of bagasse was not experimental. The design team had previously worked with bagasse pulp in packaging applications, giving them a deep understanding of how the material behaves when pressed, formed, and dried. Rather than searching for exotic solutions, the designers describe the process as “looking inside the box” — refining existing material knowledge to solve a familiar problem more responsibly.

A Small Object with Large Environmental Impact

Conventional plastic soy sauce fish containers are typically used for minutes, discarded immediately, and persist in ecosystems for years. Over time, they fragment into microplastics that enter marine food chains and eventually return to humans. The plastic-free soy sauce fish dropper aims to interrupt this cycle by offering a functionally identical object without the long-term environmental cost.

Holy Carp! demonstrates how sustainable packaging design does not require radical behavioral change—only better alignment between material, use, and disposal.

Written by Otávio Santiago, a designer dedicated to translating ideas into visual rhythm. His work spans motion, 3D, and graphic design — connecting creativity, technology, and human emotion.