Define Bottle | Eastman Innovation Lab

Define Bottle

Durable, transparent, and BPA free with Eastman Tritan™ copolyester



Carter Kostler, teen entrepreneur and inventor of Define Bottle.


Strawberry and lemon slices with basil. Cucumber and lemon slices with grated ginger. These are just some of the infused water combinations you can create with Define Bottle, a sleek, eco-friendly, and portable fresh fruit infused water bottle for people with an active lifestyle and want a twist to their H20 fix. “Define Bottle means you Define who you are, you Define what you drink, and you Define what you put in your body,“ explained Kostler.


Kostler saw a need and had a strong desire to help others develop a healthier lifestyle around water, while also being eco-friendly. Kostler shared his vision and first sketches of Define Bottle with his parents. They liked the idea and enlisted ANDesign Lab, an industrial design firm in Los Angeles, CA, to help with product design and development, and eventually guided them through manufacturing and production. The first design was Define Bottle Classic, a beautifully crafted glass and bamboo bottle.


Define Bottle’s second iteration was made of Eastman Tritan™ copolyester, a safer alternative to glass. “We looked at acrylic and polypropylene and they just didn’t measure up to Tritan’s glass-like clarity, durability, and it’s BPA-free,” noted Carla Weisman, Kostler’s parent. “Using a  BPA-free material and being associated with the Tritan™ brand was very important to me.”

All four bottle components: the base, filter, water reservoir (single and double), and twist top are made of Tritan™, except for the clear flip top. The re-freezable base piece is designed to keep the fruit cool and fresh throughout the day, while the filter piece is designed to keep infused pieces away from the mouth piece for an enjoyable drinking experience. Each piece can be easily disassembled for quick cleaning or placed in dishwasher. Tritan™ retains its aesthetic integrity after repeated trips in the dishwasher.


Define bottle currently has four bottle offerings: Define Bottle Sport (with twist top or flip top), Define Bottle Mini and Define Bottle Lite. With different bottle variations, the options to Define what’s in your bottle are endless.