The Science Behind Koozies: The Ultimate Party Anecdote

What Is a Koozie? The Ultimate Party Anecdote

Since refrigeration, people have been trying to keep individual beverage bottles and cans colder, longer. Home-use refrigerators hit the market in 1913, and only nine years later, the first individual beverage cooler was introduced. It didn’t look much like the insulated sleeves we use for cans and bottles today, but it served the same purpose. 

Today, koozies and other beverage insulators are as ubiquitous as beer itself. You’ll find them stuffed in kitchen drawers, golf bags, and boat storage, covered in corporate and small business logos. Maybe it’s because the cheap ones are often given away as promo items that we take the cooling power of koozies for granted. But when you find a high-quality koozie that keeps your beverage ice-cold in the hottest weather, you’ll discover a new appreciation for this simple tool.

What Is a Koozie?

Koozies are insulating sleeves made of foam, neoprene, or fabric, and designed to keep individual canned or bottled beverages cold. They come in different forms, including slide-on cylinders and zip-on bottle shapes. Their thickness depends on the materials used. Classic foam koozies are the thickest, at around one-quarter inch. Neoprene koozies are thinner and more flexible and offer improved insulation, which keeps your drink cold, even if you’re a slow sipper.

Like Kleenex, Rollerblade, and Thermos, Koozie is actually a trademarked brand name that has crossed over into our lexicon as a generalized term to describe any insulating sleeve for beverages. The name derives from the noun form of “cozy,” which is a soft cover (often knitted) used to keep teapots warm

How Do Koozies Work?

Koozies work like any insulating layer, by slowing conductive heat flow across temperature gradients. In the case of koozies, they slow the conductive flow of heat between both the outside air and the body heat from your hand, and your beverage. Tiny bubbles trapped inside the foam or neoprene (the two most common koozie materials) slow the conduction of heat from outside elements to your beverage container and its contents. Without the barrier created by a koozie, heat simply transfers from your hand or the air through the thin wall of your beverage container to reach the liquid inside. 

A note about conduction: Glass is a poor conductor of heat while aluminum is a good one. If keeping your beverage cold is a top priority, choose glass bottles (as long as you’re using them in a glass-safe area). 

What Are Koozies Made Of?

Koozies are most commonly made of neoprene, foam, knitted yarn, or fabric. 

Are Neoprene Koozies Better Than Foam?

Neoprene koozies provide better insulation and last longer than foam koozies, making them the better choice for keeping your beverages cool. Foam koozies are often cheaper, which makes them the top choice for swag or giveaways, but you’ll notice they fall apart after a few uses. If you’re looking for a koozie that will hold up to repeated use and abuse on fishing trips, golf outings, and tailgating, choose a neoprene koozie.

How Do You Pronounce Koozie?

Koozie is pronounced with a long “U” like food (KOO-zee) but if your friend pronounces it with a long “O,” he or she technically correct, because of the product’s origins as a “cozy.” The long “U” sound is the correct way to pronounce the trademarked spelling with a “K.”

Is It a Drink Cozy or Koozie?

Both koozie and cozy are correct. But we stand by koozie being more correct.

Whether you’re chasing bonefish on the flats or targeting sailfish on the open ocean, koozies are an essential part of the adventure — or at least the moments that follow the adventure. Grab a few to throw in your fishing bag, or pick up one as an anytime gift for one of your buddies. Everyone loves a koozie!

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