Insulated Vs Glass Coffee Carafes: Which Keeps Coffee Hotter?

For coffee lovers, there's nothing better than that first cup in the morning. The only problem is, depending on how you've brewed it, each successive cup is in danger of losing its allure. It's a delicate balance, preserving the robust flavor of your morning brew and keeping it hot. 

What many people do not know is that the two are, in fact, very much connected. The flavor of coffee changes with its temperature. Specifically, as it starts to cool, it begins to lose much of its aroma and taste. 

There are ways to make sure that first cup starts and stays perfect — beginning with preheating your coffee mug with boiling water for a tastier cup and following these tips to keep your coffee piping-hot to the last drop — but what about the rest of the freshly brewed pot? What's the best way to keep it hot?

Coffee machine makers have long since tackled this problem by placing glass carafes on hot plates. And, more recently, insulated carafes have started to make their mark in the drip coffee market, boasting more durability and sustainability, but the all-important question remains for coffee obsessives: which ones keep your coffee hotter? 

It turns out the differences are negligible. Hot plates keep coffee in glass carafes hot by turning power on and off periodically. Because of this, the temperature of your coffee sitting on a hot plate will move about 2.5 degrees Fahrenheit, either up or down, every hour. Insulated carafes, on the other hand, slowly lose their heat the longer they sit (about 4 degrees Fahrenheit after one hour).

The classic glass carafe is what comes to mind for most of us when we think of drip coffee. Aesthetically speaking, many people prefer the familiar look of a glass carafe, giving a down-home diner feel, plus the added comfort of knowing exactly how much coffee is left in the carafe. It's also lighter to carry than an insulated carafe and more affordable. The one big downside to the glass carafe is that it keeps coffee hot by sitting on a hot plate, and the longer it sits on the plate, the more unpleasant your coffee tastes. This is because the hot plate basically cooks the coffee from the moment it starts brewing and continues to do so until you turn the machine off. Your coffee stays hot, but it also becomes stronger and more bitter the longer it sits.

The insulated carafe, on the other hand, acts just like a big thermos and keeps coffee hot and fresh tasting for hours, without the need for electricity. An insulated carafe may cost more, but it will lower your home energy use, potentially helping to cut some costs in the long run. Stainless steel is also recyclable and is made to last for years, meaning it's a solid investment all around. 

Whatever type of carafe you prefer, make sure you do due diligence before buying by checking out the best drip coffee makers on the market right now.