Making espresso for your coffee drinks - cappuccinos, lattes, mochas, etc., requires that you understand the process or Ritual, as I call it. The visual clue that tells us that we have achieved Java Heaven is called the "crema". The crema is that golden marbleized foam that covers the top of the espresso. Without waxing poetic which is often done in this business, the crema is simply nirvana. It’s the foundation of the coffee culture that you have joined and the reason why you’re reading and why I’m writing this "Understanding" segment. I know this may sound intimidating, but if you spend a little time learning you will be able to teach those Starbucks kids a thing or two in short order. The reason this is so important is because it is too easy to make a bad cup of coffee. With the proper knowledge you can break the mystique and brew high quality espresso in no time at all. So, grab a cup from that good old Mr. Coffee, sit down and read everything you need to know on brewing better coffee.
Extracting espresso is part "Art" and part "Science". The "Art" is understanding the nuances of your coffee, grinder and espresso machine. The "Science" is applying specific variables to the coffee roast, fineness of grind, tamp pressure, temperature, brew pressure and time. The best method to learn how to make espresso is to begin with the science aspect. Identify the necessary variables and then apply the art aspect to fine tune the extraction (brewing). We break this mystique when we teach people everyday on how to "dial in" or "calibrate" their espresso machines. We begin with the "golden rule" of espresso making.
The Golden Rule
Double shot = 2 to 2.5 ounces in 20 to 25 seconds
This means that a double shot of espresso should equal 2 to 2.5 fluid ounces and take approximately 20 to 25 seconds to extract from the moment you start the pump until you reach the appointed liquid volume. Do not be dismayed if you have come across other versions to the rule. Stick with me on this one and in latter discussions we can explore alternatives. With this "Understanding" we will begin with the Science.
This is controlled by your machine’s thermostat. Our tests have shown that the machines we sell all fall within the proper temperature range of approximately 190 to 196 degrees so you do not have to consider this parameter when selecting a machine. Generally, you do not have to be concerned about this when you are operating the machine except under certain circumstances. I do not want to confuse you too much at this time, but as long as you watch your "ready lights" you will be just fine.
The "in cup" temperature should be around 160 to 165 degrees. The heat loss seems substantial, but it is attributable to the brew group, the air and the cup. This temperature will feel hot to the lips but not scalding.
To ensure that you get the proper "in cup" temperature you should preheat the cup as well as the brew group. The cup can be heated several ways - cup warmer on the espresso machine, hot water from the espresso machine or even hot water from your faucet.
The brew group for this discussion includes the portafilter handle (what you put the coffee into) and the part of the machine that you lock it into. This can be preheated by letting the machine warm up for 5 to 6 minutes. However, I suggest that you run 2 ounces of water through the group with the handle in place (without coffee) and into the cup. I call this shooting a blank. It is the most efficient method and the second shot is always better than the first anyway!
This is the amount of pressure developed when extracting the coffee. We look at approximately 8 to 9 bars or atmospheres as being the optimum environment. You may have noticed that the home machines show pressure ratings of 15 to 19 bars. This is purely an indication of the maximum pressure the pump is capable of producing. More pressure does not mean better coffee!