Simply put, an espresso is a concentrated shot of coffee that is made very quickly using an espresso machine.
This espresso shot is extracted by forcing a small amount of hot water through a bed of fine ground coffee, using high pressure that the machine provides.
This shot of espresso can then be consumed straight up, or be added to water, milk and other mixers to form other beverages such as your lattes, cappuccinos, mochas..etc
While most roasters usually label or categorise their coffees into Espresso Roast/Filter Roast/Roasted for Espresso/Roasted for Filter, you can actually use ANY roast and any coffee, for an espresso. The difference, is in the taste. When a roaster labels a coffee 'for espresso', they usually do this to indicate that this roast style may be better suited for the addition of milk as compared to a coffee that is roasted 'for filter'. A filter roasted coffee is usually a LIGHTER roast, which may be lost in a sea of milk. Taken straight up, this filter roast as an espresso, may be a lot brighter and punchier.
Making a good shot of espresso is highly tricky, especially with the additional variables.
With filters/pourovers, you have your variables such as water temperature, extraction time, pouring style, grind size, roast dates...etc With espressos, you have to add in variables such as your tamp pressure and machine stability.
Steps for a simple espresso.. and latte.
Before we get started on the espresso, first, switch on your machine and let it heat up. Flush your group heads and run 1 test shot through to clean out residual coffee/cleaning solution from the previous run. Dry your portafilter, and let's get started.
Simple Latte. 21:21:21
Coffee Input 21g
Extraction Time 21 seconds
Target Output 21g
Milk: 140g to 150g
Roast Date Best between 7 days to 21 days from Roast Date.
Grind. Tamp. Distribute . Extract.
Froth. Pour. Serve & Enjoy