Glass vs. Thermal Carafe: Which Is Best at Keeping Coffee Hot?
Consumer Reports' experts weigh in on the pros and cons of these coffee maker carafe types
Drip coffee makers keep coffee hot one of two ways: with a hotplate under a glass carafe (left) or in an insulated thermal carafe (right).
By Daniel Wroclawski
If you’re the kind of person who likes to brew a pot of coffee in the morning and go back for a second (or third) cup later in the day, you want a coffee maker whose carafe—be it thermal or glass—can keep your java hot for hours. Sure, you could throw your coffee in the microwave for a warm-up, but doing so can alter the flavor profile of your brew, potentially giving it a bitter or burnt taste.
Fortunately, traditional coffee makers are designed to help in one of two ways: with a hotplate under a glass carafe or in an insulated thermal carafe, which is often more expensive.
“We find that there isn’t a significant difference in temperature loss between the two types,” says Ginny Lui, a test engineer at Consumer Reports. To determine those differences on our coffee maker tests, we measure the temperature of the coffee after 30 minutes and again after 1 hour.
On average, glass carafes on hotplates can decrease—or increase—the temperature of coffee by about 2.5° F after 1 hour. Thermal carafes lose about 4° F after an hour.
We see more of a contrast in testing the use of different carafes, which Lui’s team conducts on both types. Generally, thermal carafes are heavier than glass carafes, making them more difficult to pour, and some of them dribble coffee. Thermal carafes can also be more difficult to clean. That said, the hotplates beneath glass carafes create a potential burn risk, so a thermal carafe might be best if you have children at home.
If you’re just getting started shopping for a coffee maker, get to know the basics in our Coffee Maker Buying Guide.
Best Coffee Makers With a Glass Carafe
If you prefer the ease of handling a glass carafe and the continued heating provided by a hotplate, these are three of the best drip machines with glass carafes. For more options, check out our complete coffee maker ratings.
Zojirushi Fresh Brew Plus 12-Cup (EC-YGC120)
CR’s take: The Zojirushi Fresh Brew Plus 12-Cup (EC-YGC120) is a great drip coffee maker that brews an excellent pot of coffee and has an unusual design that’s wider than it’s deep, thanks to the reservoir being next to the carafe rather than behind it. This makes it especially suitable for countertops with less depth but more width to stash an appliance. It has four warming plate settings, allowing you to keep your coffee at your desired temperature. And if you prefer your coffee on the cold side, it has a special ice basket insert for making iced coffee.
Calphalon Special Brew BVCLDCG1
CR’s take: The Calphalon Special Brew BVCLDCG1 is a terrific drip brewer from a brand known for cookware. This model earns strong marks in CR’s performance tests, with Excellent ratings for brew performance and convenience. Calphalon brewers, in general, also earn a Good rating for predicted reliability in our latest survey. This model offers brew-strength control, programming, an LED display, and a 10-cup glass carafe. It’s a bit bulky, but it comes in a stainless steel finish that should match other stainless steel appliances nicely.
Hamilton Beach 12-cup Programmable 49465R
CR’s take: The unassuming, inexpensive Hamilton Beach 12-cup Programmable 49465R might be easy to miss, but it can brew a mean cup of joe at a fantastic price. In a basic black-plastic finish, this CR Best Buy has the essentials—it’s programmable, as its name suggests, and offers auto-shutoff—and it rates Excellent for brew performance and can make a fresh pot in just 10 minutes. This model even earns a Very Good rating for convenience.
Best Coffee Makers With a Thermal Carafe
If you prefer to keep your coffee warm for long periods of time and avoid the potential for that burnt coffee taste, these are three of the best drip machines with thermal carafes that you should consider. For more options, see our drip coffee maker ratings and sort by thermal carafe under Features & Specs.
Technivorm Moccamaster KBT (79112)
CR’s take: The no-frills Technivorm Moccamaster KBT (79112) lacks brew-strength control and a programmable option that lets you set a time for when the machine brews coffee, but it delivers Very Good brew performance. Another selling point: Technivorm drip coffee makers receive Excellent ratings for reliability and owner satisfaction in CR’s member surveys.
Oxo Barista Brain 9-Cup 8710100
CR’s take: The Oxo Barista Brain 9-Cup 8710100 features a more unusual design than its comrades. With an exposed water reservoir and heating element on one side and a thermal carafe on the other, it’s a veritable conversation piece for your kitchen. Stainless and black accents might sit nicely with your larger appliances. This model aces our brew performance test and earns a Very Good convenience score, but it receives only a middling Good rating for carafe handling.
Cuisinart Coffee Center Thermal SS-20
CR’s take: The Cuisinart Coffee Center Thermal SS-20 pulls double duty as a drip machine with a thermal carafe and a K-Cup pod brewer. In our drip tests, it receives an Excellent rating for brew performance, a Very Good rating for convenience, and a Fair rating for carafe handling because of its heavier, insulated carafe. The Cuisinart model also does well in our single-serve pod machine tests, with a Very Good rating for first-cup speed and an Excellent rating for repeat speed. Our latest survey gives Cuisinart drip machines a Good rating for predicted reliability and an Excellent rating for owner satisfaction.
Editor’s Note: A version of this article also appeared in the November 2019 issue of Consumer Reports magazine.
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