With PID

Many espresso machines have a feature called a PID or PID controller, a very common question people have when they are looking for espresso machines is, "What is a PID and why would I want to have an espresso machine with this feature?". 

PID stands for Proportional Integral Derivative. Fancy name, but it's pretty much a temperature controller that uses an advanced algorithm to maintain the temperature of the machine at a programmed temperature. Most PID controllers allows users to increase or decrease the temperature, which can have a big impact on the flavor of espresso being brewed. Every coffee bean has a different ideal brew temperature, so having a PID temperature adjuster for brewing espresso has the biggest impact, but PIDs can also be used to adjust the temperature of the steam boiler. Increasing or decreasing the steam boiler temperature will allow the user to fine tune the steaming performance of the machine. Some people prefer a hotter and drier steam, while others prefer the steam to be a bit cooler. A higher temperature means more steam pressure and a lower temperature means less steam pressure.