A timer is a specialized type of clock used to measure a set length of time. Tea brewers, especially those brewing styles requiring infusion time of above one minute, often choose to use a timer to help prevent over- and underbrewing.

Common timers used in tea brewing can be sand-based, mechanical, or digital, though a growing trend is the use of specialized software applications. Because tea brewing does not require more than 15 minutes of infusion time, timers with shorter time capacities are often preferable to those that can measure several hours.

Sand Timer

Example of a sandglass timer. Perfect Tea Timer.

A sand timer, also known as an egg timer, sand glass, sand clock, or hour glass, consists of two glass bulbs placed one on top of the other which are joined by a connective tube or neck. A pre-determined measure of sand is placed into one bulb, and when the glass is inverted, the sand flows at a certain rate into the second bulb. When all the sand has run into the second bulb, the glass is inverted again to measure another period of time.

Factors affecting the amount of time a sand glass measures includes the size and angle of the bulbs, the volume and fineness of sand, the width of the neck. Because of these variables, sand timers are more accurate at smaller amounts of time. Today, they are usually found only in intervals of a few minutes.

The sand timer's chief advantage is that it requires no battery or electrical power to operate and will practically never malfunction. However, any particular sand timer can only accurately measure one set period of time. Therefore, several sand timers ranging from a capacity of 30 seconds to 15 minutes may be needed by any one brewer. Some manufacturers have attempted to expand the range of their products by making timers holding multiple sand vials. However, many brewers still find the ranges afforded by these products too limiting. The sand timer must also be visually attended in order to catch the moment when the last grain of sand falls to the second bulb. Many brewers find the lack of an audible alarm a sever handicap.

Mechanical Timer

Example of a mechanical timer. 60-minute mechanical kitchen timer.

There are several types of mechanical timers, all of which are powered some sort of physical action. Clock timers open and close a circuit based on the position of internal or external clockwork. Spring-driven timers use a spring and trip lever to generate mechanical action. Dashpot timers pass compressed air or hydraulic fluid into or out of a contained space through an opening with a fixed or variable diameter. However, most available kitchen timers use a flat beater that spins against air resistance.

Most mechanical timers make a pleasant clicking or 'tick-tock' noise as they count down an interval of time and conclude their interval with a loud ring. Unfortunately, mechanical kitchen timers are often grossly inaccurate, particularly at short time intervals. In fact, most such timers have a minimum settable time of 5 minutes, rendering them completely useless for most tea brewing applications.

As with sand timers, the mechanical timer's chief advantage is that it requires no battery or electrical power to operate. However, due to its many moving parts, it can easily malfunction.

Digital Timer

Example of a digital timer. Taylor digital timer with clock, #5807.

Unlike mechanical or sand timers, digital timers are more complicated machines. However, they are also much more accurate.

At their basest, digital timers are they are simply quartz clocks with special electronics. Usually basic watch technology is used in their construction. While digital timers had been quite expensive in the past, the costs of integrated circuitry has fallen to the point where a digital timer is often less expensive than its mechanical counterparts.

Digital timers often offer a myriad of features, the most popular of which include alarms that can be set to either sound, vibrate, or put on a small light show. Timers with functions such as these make great time-measurement tools for those who are blind or deaf. Other features include timing to the nanosecond, large display faces, multiple timing functions. Most digital timers also offer 'counting-up' functions, allowing a user to know exactly how much time has elapsed since the sound of the alarm.

Though digital timers run on electricity, most basic kitchen timers are powered by a simple, long-lasting AAA battery.

Software Timer

Example of a software timer. Tea Timer for Mac OS X

A plethora of timing software applications exists for free download on the internet for every operating platform, and many exist expressly for the purpose of timing different teas. Some online tea vendors, such as Adagio, even offer their own tea timer applications.

These various programs can offer as much or more functions than a digital timer, and can even be programmed to 'remember' times for specific teas. However, many of the programs take several seconds to load. For optimum accuracy, then, they must be opened before brewing begins.