Pump-driven espresso machines are the type of small kitchen appliance found in the homes of those who enjoy having the ability to control the strength and consistency of his/her espresso brew.
There are several types of espresso machines. The pump-driven models sell more and therefore have become more popular. Most versions also have a steam wand. The action itself is simple. Water that is stored in tanks is pulled into a heating chamber (a metal compartment housing a heating device) by a pump. The heating device is a wire that has been coiled and then placed within plaster; this can vary depending on price.
The water is heated using electricity once the coil warms up. After the water reaches the appropriate temperature, it travels through a valve and pushed through a filter, which leads to a spout from which the espresso pours into a shot glass. If the machine is also equipped for steam, water can be directed through the valve connected to the heating device to reach the steam wand.
Steams wands are metal pipes shaped like an ‘L’ and used to release water that has been converted into steam as well as froth milk for espresso and other coffee styles. Most espresso machines will have a control panel with indications for power to the machine and temperature for the water once it has been heated sufficiently. The valve control is built to direct that water to either the filter system or to the steam wand.
To make just a shot of espresso, the espresso machine needs to have water in its tank and its filter basket containing ¼ oz. of blended espresso beans that have been finely ground and packed tightly with the use of a tamper, a heavy tool used to press freshly ground coffee as dense as possible. The filter is then placed into the machine below the head casing where the water is forced through the ground espresso beans.
Once the machine has power, a light indicates when the water has reached the level just below boiling and brewing commences in earnest. This is when the valve is dialed to the setting for espresso and hot water that has been pressurized is pushed through the head and the coffee grounds by the pump. Spouts underneath the filtration system catch the liquid in shot glasses waiting for the espresso below. The entire brewing process yields 1.5 ounces of espresso in roughly thirty seconds.
The Dirty Secrets About Espresso Machines Credit Picture License: nalundgaard via photopin cc