Timers are used in coffee makers for various applications. The most common applications are: timing the brewing, starting the coffee maker, or turning it off, timing coffee grinders, as a way to measure the amount of coffee beans used, timing the extraction as a way of controlling the brewed coffee volume.
A timer is a specialized type of clock for measuring time intervals. A timer which counts upwards from zero for measuring elapsed time is often called a stopwatch, a device which counts down from a specified time interval is more usually called a timer. A simple example is an hourglass. Some timers sound an audible indication that the time interval has expired. Time switches, timing mechanisms which activate a switch, are sometimes called “timers”.
The most typical use for a timer within the context of coffee is timing the brew or extraction time. It is very important to time the extraction time in order to achieve well balanced, well extracted coffee.
For espresso extraction, ideally the timer would record a total extraction time of between 20 and 30 seconds from when the brew button is pressed.
For Filter coffee, the brewing should be complete when the timer reads a time of between 2 and a half and 3 minutes.
If the timer is recording different times to the ones stated above, an extraction factor, such as grind size, water volume or coffee dose, needs to be adjusted.