My grandmother’s waterpot was not the first I ever saw, but it was the first I got close enough to look inside and drink from. I was immediately shocked by how cold the water was. Curious as I was, I began asking questions about the science behind it. It was in this process that I learned about its smaller counterpart, the gourd, which was easier to move around with and drink from, yet had the same cooling effect. Learning this gave me a lot to ponder in relation to the insulated drinking cups we have today.

Sometime in 2022, the world woke to find that a particular kind of cup, the travel tumbler, had taken over the market. These are insulated bottles or cups which are, simply put, designed to keep a drink hot or cold for an extended period. It is one of the few consumer trends that has surprisingly endured, remaining strong four years later. Beyond excellent marketing and stylish design, its success also suggests that these kinds of drinking containers meet a genuine need. Before their popularity, the most available options were regular sports bottles, some plastic and others steel. They were often large, heavy, difficult to hold and, in many cases, not designed for the increasingly mobile lives of their users. The travel tumbler offered something different: a cup that could keep a drink at its temperature while fitting comfortably into everyday movement such as carrying a laptop.

The evolution of insulated water bottles, from the heavier containers of the 1900s and early 2000s to the drinking cups and mugs that have taken over the market, raises questions about production choices and environmental care. Manufacturers of these products, particularly those made from stainless steel, often point to their durability and recyclability as evidence of their sustainability. And there is some truth to this. A durable, reusable cup can reduce dependence on disposable containers, while stainless steel can be recycled at the end of its useful life. But sustainability cannot begin at the recycling bin. It must also account for what happens before the product gets there. The popularity of these cups, therefore, raises a question that is less visible than their carefully designed exteriors: what does it cost the planet to make them?

How much energy is required to make the cup? Where do its raw materials come from? What happens in the mines where those materials are extracted? How much carbon is released during processing and manufacturing? And, perhaps most importantly, how long will the consumer actually use the cup before replacing it with another? A reusable object may have a longer life than a disposable one, but its environmental value cannot be determined simply by what happens to it at the end of that life. We also have to ask what happened at the beginning.

Many are made with food-grade stainless steel, using two layers with a vacuum between them to reduce heat transfer. Producing stainless steel, however, requires the extraction and processing of raw materials such as iron, chromium and nickel, as well as significant amounts of energy. The environmental cost therefore begins long before the finished cup is placed on a shelf. Mining, refining, manufacturing and transportation all form part of the product’s life cycle and greatly affect our climate. The greenhouse gases produced throughout energy-intensive extraction and manufacturing contribute to the accumulation of emissions responsible for global warming. 

There is another part of the equation: consumer behaviour. Rather than replacing a disposable cup with one durable tumbler and using it for years, some consumers are collecting them in different colours and designs. The object marketed as an alternative to excessive consumption can itself become another object of consumption. If a company describes a product as sustainable because it is reusable and recyclable, but its consumers are buying several versions of it, where does responsibility lie?

This does not mean that insulated cups are inherently bad. A durable cup that is used for years can reduce dependence on disposable containers, and stainless steel can be recycled at the end of its useful life. The problem is that recyclability can become the most visible part of a product’s environmental story, while the extraction and manufacturing required to create it remain largely invisible. 

This is where I think about my grandmother’s waterpot and the gourd. What if, instead of continually improving industrial materials to reproduce properties that already exist in nature, we looked more closely at the materials nature has already given us?
The waterpot can keep water cool. The gourd can serve as a vessel for carrying and drinking water. Both have existed for generations without requiring the climate-harmful mining and industrial processing involved in producing stainless steel. Gourds are made from the hardened shells of fruits that grow on climbing vines. Traditionally, they are allowed to dry for months before being prepared for use as containers. In some communities, their interiors are treated with natural materials such as beeswax to make them suitable for holding liquids. 

Gourds are not perfect substitutes for the modern tumbler. Moreover, their preparation processes are local and may not easily translate into mass production. But technology can help investigate this knowledge. If research and manufacturing can transform timber into paper, furniture and countless other products, surely they can also explore how plant-based materials, clay and other naturally insulating materials might be developed into durable, functional and beautiful vessels for contemporary life.
Perhaps the future of sustainable production and design is not always about inventing something more sophisticated, but about paying closer attention to what nature, and the people who have lived close to it, already knows how to do. Modernity does not have to be at the expense of the earth.

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