If you’ve ever stopped mid-sip to admire the smooth, ice-cold edge of your morning iced coffee or noticed that your afternoon hot tea stayed steamy for hours in your go-to tumbler, you’ve probably wondered: what are these durable, everyday workhorses actually made of? As a tumbler and mug supplier who’s spent the last 12 years testing materials, troubleshooting common customer complaints, and refining every detail of the products we ship, I’m here to break down the science behind the most popular tumbler materials, what makes each unique, and which ones might work best for your needs (whether you’re stocking a café, outfitting a team, or just restocking your personal collection). Tumbler & Mug
Let’s start with the most ubiquitous tumbler material out there: 18/8 stainless steel. If you’ve ever held a double-walled tumbler that weighs just enough to feel sturdy without being bulky, chances are it’s made from this alloy. For anyone new to the numbers game, 18/8 refers to the composition: 18% chromium and 8% nickel, a balance chosen for its unmatched combination of durability, corrosion resistance, and food safety. Chromium forms a thin, invisible oxide layer on the steel’s surface that protects it from rust, even when in constant contact with acidic drinks like lemon water or tomato juice—something that cheap, lower-grade steel alloys can’t do. Nickel, meanwhile, boosts the steel’s flexibility, making it resistant to dents when you toss it in a backpack or set it down on a busy bar counter.
From a performance standpoint, 18/8 stainless steel is a thermal insulator’s dream. Unlike glass or plastic, it’s a non-porous material, meaning it won’t absorb flavors or odors over time. I’ve seen customers come to us with old plastic tumblers that still smelled like the chai tea they used six months prior; that’s never a problem with 18/8 steel. It’s also the gold standard for temperature retention. Double-walled, vacuum-sealed 18/8 tumblers will keep hot drinks at 140°F (or 60°C) for up to 12 hours and cold drinks at 40°F (or 4°C) for up to 24 hours—numbers we test rigorously in our lab every single month, because we know that’s the feature that keeps customers coming back. The only minor downsides? It’s not transparent, so you can’t easily see how much liquid is left, and it can scratch if you use abrasive sponges. Most of our customers prefer it for its long lifespan, though; a well-cared-for 18/8 tumbler can last a decade or more, making it a far more sustainable choice than disposable cups or even cheaper materials that need replacing every year or two.
Next up, a material that’s been growing in popularity over the last decade, especially among customers who prioritize lightweight designs and shatter resistance: BPA-free plastic. Wait, let’s be clear: not all plastic is created equal, and the term “BPA-free” only tells part of the story. The most common plastic used for tumblers is Tritan copolyester, a material developed by Eastman that’s been rigorously tested for food safety. Unlike older plastics that could leach chemicals when exposed to hot liquids (a big concern for many customers), Tritan is heat-resistant up to 212°F (100°C), so it won’t warp or leach even if you pour boiling water into a tumbler for soup or tea. It’s also incredibly lightweight—half the weight of a comparable stainless steel tumbler—and virtually unbreakable, which makes it a top choice for kids’ tumblers, hiking, or anyone who travels light.
That said, plastic does have its limits when it comes to temperature retention. Single-walled plastic tumblers will only keep drinks at their desired temperature for an hour or two max, though double-walled insulated plastic options have come a long way in recent years, with some matching the cold retention of stainless steel for shorter periods. The downside? Plastic is porous, so over time, it can absorb strong flavors (think: a week-old batch of mint chocolate chip smoothie that lingers in the tumbler) and it’s more prone to scratches and discoloration from UV exposure if you leave it in direct sunlight. It’s also less recyclable than metal for many consumers, though Tritan can be recycled through specialized programs, something we make a point of disclosing to all our bulk order customers.
For customers who want the best of both worlds: the clarity of glass and the durability of metal, there’s borosilicate glass tumblers. If you’ve ever used a Pyrex baking dish, you’re already familiar with borosilicate glass, which has a low coefficient of thermal expansion—meaning it can withstand extreme temperature changes without cracking. Pouring boiling water into a cold glass tumbler? No problem, as long as it’s made of borosilicate (regular glass would shatter instantly). It’s fully non-porous, so it never absorbs flavors or odors, and it’s transparent, making it easy to track your liquid intake or show off a colorful cocktail. It’s also 100% recyclable and free of any chemicals like BPA or lead, which appeals to health-conscious buyers.
The trade-off is that glass is fragile. It will chip or break if dropped on a hard surface like concrete, which makes it less ideal for outdoor use or households with young kids. It’s also heavier than plastic and most stainless steel options, though thin-walled borosilicate glass tumblers have gotten much lighter in recent years. At our company, we offer a line of borosilicate tumblers with silicone sleeves to add grip and a layer of protection against breaks, which has cut customer complaints about chipping by 70% over the last two years. For customers who prioritize ease of cleaning, transparency, and chemical safety above all else, glass is a fantastic choice—just be mindful of how you handle it.
A material that’s gaining traction in the premium tumbler market over the last five years is copper. Copper tumblers are most famous for their use in traditional mint juleps, but they’re growing in popularity for everyday use too. Copper has natural antibacterial properties, with studies showing that it kills 99.9% of harmful bacteria like E. coli and salmonella within two hours of contact. That’s a huge selling point for customers who use their tumblers for water, especially in shared spaces like offices or gyms. It’s also highly thermally conductive, meaning it can keep cold drinks extra icy for hours—some copper tumblers we tested kept ice frozen for up to 36 hours in our 70°F room temperature test.
That said, pure copper can react with acidic drinks like orange juice or coffee over time, leaving a metallic aftertaste or discoloring the drink. That’s why most copper tumblers you’ll find on the market have an inner lining of stainless steel or food-grade tin to prevent that reaction. The outer copper layer is often polished for a sleek, luxurious look, making these tumblers a popular choice for gift sets or brand activations. They’re also slightly more expensive than stainless steel or plastic, so they’re better suited for customers willing to pay a premium for unique benefits like antibacterial properties or fast cold retention.
Now, let’s talk about materials you’ll almost never see in a high-quality tumbler, and why: low-grade carbon steel, aluminum, and non-food-grade silicone. Carbon steel is cheap, but it rusts easily when exposed to moisture, and it can’t be used for hot drinks at all because it gets too hot to hold. Aluminum is lightweight, but it reacts with acidic drinks, leaving a metallic taste, and it’s not as durable as stainless steel. Non-food-grade silicone, which is often used as a cheap sleeve or seal, can leach chemicals when exposed to high temperatures, which is why we only use FDA-approved, food-grade silicone for all our tumbler lids and accessories.
So, as a tumbler and mug supplier with thousands of customers ranging from small café owners to large corporate buyers, what’s our advice for choosing the right material? If you need a workhorse that will last for years, retain temperature perfectly, and work for hot and cold drinks, 18/8 stainless steel is the way to go. If you’re looking for something lightweight and unbreakable for kids or outdoor activities, Tritan plastic is a great option. If you prioritize clarity, safety, and no flavor absorption, go for borosilicate glass. And if you want a premium option with natural antibacterial benefits, copper is worth the investment.
At the end of the day, the best tumbler material depends on your specific needs, budget, and lifestyle. We’ve tested every one of these materials extensively in our own operations, because we know that a tumbler is more than just a container—it’s a daily companion that carries your coffee, your tea, your water, and your favorite drinks through work, hikes, road trips, and lazy afternoons at home.
If you’re a business owner looking to order bulk tumblers for your café, team, or promotional campaign, or if you’re an individual who wants to learn more about the best material for your daily use, we’d love to chat. We offer custom branding, bulk pricing, and can help you find exactly what you’re looking for, no matter your needs.
Shaker Bottle References:
- Food and Drug Administration. (2023). Food-contact materials: Plastics. U.S. Department of Health and Human Services.
- Eastman Chemical Company. (2022). Tritan copolyester: Food safety and performance data.
- International Stainless Steel Forum. (2021). 18/8 stainless steel: Composition and applications for food contact.
- Corning Incorporated. (2020). Borosilicate glass properties and use in consumer products.
- World Health Organization. (2019). Antimicrobial properties of copper for food and water contact.
Jinhua Jinjun E-commerce Co., Ltd.
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