If you are looking at buying an espresso machine and you have been looking at the different models available, you may have noticed that many of the descriptions of the machines talk about features such as ’steam-driven’, ‘pump-driven’ and ‘piston-driven’. Although these seem to be quite important it is unlikely that you actually know what they mean unless you are a barista. This is where I am going to help you! A pump-driven machine is the most common type of machine on the market and is the type which you will find in most coffee shops. This is where a motor-driven pump creates the force which is necessary to force…