The 10 Best Thermal Carafes
10. Thermos 32-Ounce
9. Melitta Pour-Over
8. Copco Chloe 1 Quart
7. Zojirushi Vacuum Insulated
6. Vremi 51 Oz
4. JPVictoria CC-10320
3. Cresimo Double Walled
2. Hastings Collective Heavy Duty
1. Hiware HTC64
How To Choose a Thermal Carafe
While perhaps the selection process for the right thermal carafe is not so complex as choosing the right computer, so impactful as finding the right school, or so costly as buying the perfect house, it is a decision that nonetheless merits a good dose of time and consideration. This is so because most such carafes -- also often known as insulated pitchers -- are durable enough to last for many years; if you're going to buy one, you might as well make sure it's one you'll long appreciate.
Fortunately, the thermal carafe selection process is also quite straightforward and can be handled with a simple methodology. Just weigh a few different factors and then make your decision based on which attributes are the most important to you within each category.
The most basic but ultimately also the most important consideration you must make is about simple liquid containing capacity. If you need a carafe than can keep an entire pot of coffee warm well after it has been brewed, then you will need one with a capacity of at least sixty ounces. (A standardized cup of coffee is measured at 150 milliliters, or 5.7 ounces, while standard full-sized coffeemakers brew twelve cup pots, thus the full pot will contain around 58 ounces.) Many carafes have a two-liter capacity which is more than large enough for big pots of coffee, tea, or other beverages, and also makes them ideal for keeping large servings of juices or soft drinks cool. (Note that a carbonated beverage is not to be placed in a sealed carafe based on the pressure that will build up within and the potential for spills or even for injury if the cap is propelled off the body.)
Next, consider the physical shape and size of the carafe, capacity notwithstanding. Some units are tall and slender and can fit into larger vehicle cupholders, making them ideal travel companions for the commuter or for use during a road trip. Other carafes are wider and more squat and will resist tipping over even if bumped or jostled in high-traffic areas, such as an office's break room or on a picnic table.
We arrive next at the key question of aesthetics; while of course the capacity and design of your carafe is more important that how the unit looks, as a carafe will likely be used during dinner parties, at holiday celebrations, or any other time when large groups are gathered, you don't want to have it clash with or detract from the otherwise elegant and stylish decor you will establish with fine flatware, plates, and associated trimmings.
Finally, note that while many carafes are perfectly safe for dishwasher cleaning, with some hand washing is advised. If this seems like a laborious prospect, then strike the latter from your list; just keep in mind that some hand-wash options are also some of the most handsome carafes.
How Does a Carafe's Insulation Work, Anyway?
Insulation provides no warming or cooling properties, it simply prevents heat gain. In the case of a cold drink kept in a carafe on a hot day, the reduced heat gain relates to the chilled beverage kept apart from external heat. With a hot beverage in the carafe, it is the ambient temperature that is prevented from (modest) heat gain. Keep in mind that, according to the scientific community, there is actually no such thing as "cold," there are only varying degrees of heat, or the lack thereof.
Most thermal carafes keep beverages insulated -- protected against the loss of internal heat or cold, e.g. -- using variations on a similar design. They used a double-walled structure with a gap left between the exterior wall and the interior lining. The space between these walls is often vacuum-sealed, which is to say all of the air within has been mechanically removed before the space was closed off and rendered airtight.
This lack of air leads to a much slower transfer of heat, and this is true in both directions, e.g. from the ambient temperature of the room or the outdoors and from the temperature of the beverage within the carafe. Some carafes also use another insulating material (usually a type of foam) in the space between the walls, thus approximating the design of a cooler intended for use in the warm outdoors.
Hacks for Helping Your Beverage Stay Cold or Hot
The simplest way to help keep the beverages stored in your carafe cooler for longer is to make sure they are as cold as possible when you initially pour them in. This is also true for warmth, of course; the hotter the drink is as it enters the insulated carafe, the longer it will stay warm.
To cool a beverage as much as possible without the risk of freezing it, you can set your fridge to around 34-degrees Fahrenheit, or you can keep the beverage in a thin container (a glass or plastic bottle) in an ice bath for an hour or so before decanting it. The best way to keep drinks extra cold, however, is to make ice cubes out of the beverage and to add these to the carafe. A few large, frozen cubes of orange juice floated in liquid OJ won't impact the taste of the juice but will keep it cool, for example.
When it comes to hot beverages in the carafe, keeping them warm for a long period is a bit more challenging, because you can't readily find a hot object that can be dropped into the liquid to add additional warmth. Instead, you can add some extra insulation and/or warmth to the carafe itself and help it keep its contents warm. Consider storing the carafe in an insulated cooler when it's not actively serving drinks, or even wrapping it in a heated blanket. There are also heated lunch boxes that can accommodate some moderately sized carafes. Finally, if you need to re-heat or maintain the temperature of a beverage as its warmth is lost over the hours, consider using an immersion heater to restore the warmth in a matter of minutes. This will not be a viable option while out at the campsite, but is quick and easy wherever an outlet is handy.