digging into glass.

Glass is the holy grail of zero waste - jars upon jars upon jars holding bulk dry goods, coffee, leftovers, you name it. I prefer glass over plastic or even metal because it's nontoxic and pretty much endlessly recyclable...plus it's so lovely. I love opening my cabinets and seeing jars of dried goods lined up and waiting to be cooked. My friend Bailey recently got a peek into how it's made, and what she learned was so interesting we wanted to share. A bit of a departure from what I normally chat about here, but it can be illuminating to remember that behind (almost) everything we use, there's a manufacturing process. Here's Bailey:

Through my day job in workforce development in the manufacturing industry, I have come to understand the industry that supplies, and feeds on, our consumer culture. I’ve toured metal manufacturers that produce the gears that make nearly everything in your car work, a company that produces (but doesn’t fill) aerosol cans, and a massive chocolate factory that sometimes makes the whole of downtown Chicago smell divine. I often feel a disconnect between my values and my work; manufacturing lies at the heart of mass consumption, something that zero wasters and environmentalists are at odds with.

Last week I had the opportunity to tour a glass manufacturing plant in Illinois; the company I met with also works internationally, with plants in 21 countries over the globe. In their plant just outside of Chicago, they produce the glass containers that house so many foods and drinks: Honest brand lemonade, Tabasco sauce, Mt. Olive pickles, Svedka vodka, and more. They even make Ball jars! I was pretty excited to get an insider look into how my favorite packaging material is manufactured.  

To start the meeting they showed me a video about their production process. In a nutshell:

  • The three primary ingredients used to make glass are all natural materials: sand, limestone, and soda ash. Typically, 10-60% of any final batch is composed of recycled crushed glass, called The majority of this recycled material comes of the containers they produced which did not meet quality standards. Only a small portion comes from the general public’s recyclables.
  • That mixture is heated in an industrial furnace, turning it into molten glass.  It flows out of the furnace and is divided into the amounts needed for the container being produced.
  • These "gobs" of blass are dropped into a series of molds depending on the shape of the jar. Lastly, compressed air is blown into the top, expanding the molten glass to shape of the mold.

Every individual bottle is checked for quality. Those that do not meet standards are recycled as cullet. Those that move forward are cooled and sprayed with a “food grade organic coating material” to lubricate and strengthen them. Finished bottles are either shipped in bulk or placed in cardboard packaging and stacked for shipment. The pallets are strapped and wrapped in plastic wrap for stabilization and sterilization before being shipped to the customer.

In my conversations with the operations manager, he mentioned the glass industry’s competition with the plastic industry. Glass is more costly to manufacture than plastic upfront, but it is infinitely recyclable and its incineration does not cause carcinogens to be released in the air. He emphasized that the majority of plastics end up in waterways and landfills, and that the small percentage of it that is recycled reduces in quality over time, so that even recyclable plastics eventually end up as trash.

One interesting note about their manufacturing process is that it's structured to "add value to the packaging design process.” They offer custom glass designs, something that is unique to North America. In Europe, their glass plants have thirty to forty molds for their customers to choose from. Instead, the shapes of glass jars over here are intensely brand-oriented: think Crown Royale bottles, Starbucks Frappuino bottles, Tanqueray gin.

One of the many wonderful tenants of zero waste is reducing that supply chain by making it yourself, buying it from the creator, or buying in bulk. With bulk, I choose my purchases based on what I really want - not based on what package looks most familiar. I’m happy to be a part of a movement that is slowly galvanizing people’s purchasing power to reduce the imprint of the production process and, where necessary, support more ethical industry processes. 

Thanks, Bailey! If you're curious about how other things are made/disposed of, Colleen of No Trash Project also writes well about the topic. Check out a few of her posts here, here, here, and here.