How to prepare espresso coffee

Preparing and making espresso coffee
When a traditional Italian espresso machine is used to prepare espresso coffee, a number of factors need to be considered and controlled to ensure a quality espresso based beverage is made.
Temperature
Temperature is key to producing a good espresso, and while your espresso machine will do some of the work for you, there are things you need to do to ensure a quality drink. Keep the Portafilts in the group between shots, cold portafilts will make a cold espresso. If it is a long time since the group you are using made a coffee, run a cooling shot of water into the waste tray while you are loading the portafilt.
Grind
The grind of your coffee has a fundamental impact on the quality of coffee you produce. The coarser you grind coffee the faster water runs through it and the weaker the brew will be. Grind finer and the water will pass through the coffee slower extracting more taste. In terms of espresso you should grind the coffee fine enough so that from pressing the brew button to getting one fluid ounce of espresso in the cup should take between 22 and 25 seconds. Beware, grind too fine and the water will not pass through the coffee at all, or so slowly that the resulting espresso will be bitter and overextracted. It is worth noting that for espresso the quality of crema is related to both the fineness of the grind and the freshness of the beans. Crema will be reduced the older the beans, also exposing the beans to air will reduce crema, so do not fill the grinder bean hopper if it will take you days to use the beans. Also once ground coffee stales very quickly, within hours really, so do not grind large amounts if you can not use it wirhin an hour. The ground coffee chamber of a commercial espresso grindee will hold around 45 cups, do not fill it unless you will be using it.
Keep it clean
It may seem obvious, but many people fail to appreciate how much difference to the taste of coffee a clean machine will make. That does not mean you can polish the outside and that will do. The group handles, otherwise known as portafilt's, need cleaning daily. Remove the baskets from the handles and soak in cold water overnight. Wipe off any stubborn oils the next day. Once a week soak pans and handles in dusty caff cleaning powder and hot water to clean thoroughly. Backflush nightly with water, and once a week with dusty caff. Have your group seals and diffusers replaced once a year, do this yourself or have an engineer do it for you. Coffee oils build up on any surface the coffee comes into with, and if left will go rancid affecting every brew you make.
Techniques of the Barista
To get the best espresso shots, you need to observe the techniques of a Barista - professional espresso coffee maker, and replicate them. You still need to understand the basics.
Little and often, this is how a barista grinds coffee for espresso.
After emptying the waste grounds, wipe dry and clean the portafilt.
Load the correct dose of ground coffee into the portafilt, and them tamp hard with a hand tamper. You are auming for 30 lbs per square inch pressure.
If the group has not been used very recently, run a shot of water through as a cooling flush before locking the portafilt in.
Brew your espresso shot and serve immediately.
The little points make a big difference to espresso shot quality, it can help a great deal to watch an expert in action or to take some advanced Barista courses. If you get the chance to visit a Barista Championship heat you can learn a great deal about the Art of making espresso, and the skills and attention to detail involved. Judges rate not only the drinks imvolved (four of each, espresso, cappuccino, signature drink) but also the technical aspect of machine use, cleanliness and serving skill.
Quality coffee sells itself, so don't cut corners with staff, make sure they know what they are doing or get some training for them. Buying expensive equipment will not make your drinks perfect, your staff will, so invest in them as well.