A coffee urn is a large, usually metal vessel capable of both making big quantities of coffee and keeping it warm for extended periods of time. Most are electric, but some are heated with propane, oil, or other internal fuel source. Urns are very popular at large meetings and banquets as they save hosts the trouble of constantly freshening smaller pots or carafes. Most make coffee easily accessible through a central spigot, so that guests can dispense however much they want while allowing the remainder to remain warm.
Main Purpose
Coffee urns are most popular in the entertainment and hostessing industries — basically, any place where big groups of people need ready access to coffee. The primary benefit of using this device is efficiency and consistency. Urns are often set up in hotel lobbies, for instance, so that guests can help themselves in the morning. They may be used in the home when throwing large parties or entertaining a lot of guests. Commercial varieties are also popular at weddings, large receptions, or meetings. Fancier urns may be set out for self-service, though they also may be kept behind the scenes in places like restaurants, accessible only to wait staff and servers.
Basic Mechanics
Aside from capacity, the biggest benefit of a coffee urn is its ease of use. Most serve as both brewers and dispensers, which makes them something of an all-in-one appliance. A typical urn comes with a special brewing chamber that may or may not require a coffee filter. Users will fill this compartment with coffee grounds, then add water to the main chamber. The unit must then be plugged on or lit, depending on specifics of the heat source. Once the coffee has reached its ideal strength, the appliance will go into a holding pattern that keeps the coffee warm but does not continue to brew it.
Choosing the Right Size
Many different manufacturers make and sell coffee urns, which leads to a lot of variety. As a general rule, each is capable of holding at least 10 cups of coffee, though many can accommodate much more. It is not uncommon, for instance, to find a commercial-grade coffee urn that can serve upwards of 100 people at a time. Most of the time, urns are sized by range: some can make between 10 and 20 cups, for instance, while others are marketed as 35 to 55, 70 to 100, and so on. Part of the reason for the range is that not all coffee cups are the same size; they usually hold anywhere from 4 to 6 ounces (118 to 177.4 ml), although some people use larger mugs. The price of the urn usually varies depending both on capacity and quality of workmanship and manufacturing.
One of the most important parts of a coffee urn is how it dispenses coffee. Urns typically have a spigot, or pull-handle, located either in the center or at the base. A good-quality spigot will dispense coffee quickly and accurately without dripping. More poorly made models are prone to dripping and squeaking, and may not always shut off properly. This can cause a problem in public settings, and often requires a lot of extra preparation when it comes to preventing big spills and messes. Hosts who are worried about the quality of their spigots often place small drip trays beneath the outlet, or else line the table or stand beneath the urn with absorbent towels.
Heating Considerations
Electric coffee urns are the most common type, and these models either come with an attached cord or are designed to fit into an electric “base” or plugged-in heating unit. The disadvantage to this style is that it must always be located near a wall outlet or extension cord. Many electric pots include a thermostat that helps keep the coffee at a consistent temperature.
Self-heating models are another option. Urns of this type are designed to sit over a small heating chamber containing either a gas, oil, or candle flame. There is a lot more flexibility when it comes to where this kind of coffee urn can go, but someone will need to monitor it to be sure that the flame doesn’t go out. If the heat is extinguished, the coffee inside will soon grow cold. The temperature of the coffee in this type of pot also can not always be as closely controlled as with an electric urn.
Care and Cleaning
One of the biggest complaints people have about coffee urns is that they can be very difficult to clean, in part because of how many different components each has. Electric models cannot usually be submerged in water, which can make thorough cleaning somewhat difficult. Hot soapy water is usually best, and urns should be left to soak for a few hours if at all possible to help remove the taste of old or stale coffee.
Cleaning is also a lot easier if coffee is the only thing that was in the urn. It can be tempting to add sugar and possibly even cream to the water chamber in order to create a perfectly balanced cup of coffee right from the spigot, but this is almost universally discouraged by manufacturers and food safety experts alike. Adding sugar and dairy products raises the likelihood of bacterial growth if the urn is not properly cleaned, and can also clog up the brewing mechanisms inside. In most cases, additives will sink to the bottom, which means that some cups dispensed will be quite sweet or creamy but others almost bitter in comparison. It is usually best to set cream and sugar alongside the urn so that each individual can make his or her cup to order.
Difference Between Urns and Carafes
It can be easy to confuse urns and carafes, and many have a similar outside appearance. The main difference comes in mechanics. A carafe is a way to dispense and keep warm coffee that has already been brewed, whereas an urn takes care of both the brewing and the warming. A number of cafes and coffee shops will rent out filled carafes of coffee that hosts can use for special events, which can be a good compromise when a certain kind of coffee is desired. An added benefit here is that the carafe can simply be returned when the party is over, often without having to worry about washing it.