While single boiler machines are extremely cost effective, they do suffer from wide temperature fluctuations which can result in poorly extracted espresso. As such, the technique for 'temperature surfing' was developed by home espresso enthusiasts and you can watch as Gail goes through the process on a Rancilio Silvia. This technique can be applied to any single boiler machine -- such as the Saeco Aroma, Ascaso Basic or Dream and any of the Gaggia semi-automatic espresso machines.