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Espresso is more than a drink. It’s not just a cup of coffee. It’s more than the mixture of ground coffee beans and water at a particular temperature. Espresso is a state of mind. It is an elixir. The pursuit of the perfect shot of espresso is akin to the pursuit of the Holy Grail in the minds of many espresso lovers. They even refer to that elusive perfect shot as “the god shot”, elevating it above ordinary mortal drinks and into the realm of ambrosia. There are even those who theorize that espresso WAS ambrosia.
Espresso is coffee made by heating water to temperatures about 15 degrees below boiling, then forcing it through a compacted puck of very finely ground coffee beans at about 9 atmospheres of pressure. The reasons for the precise temperature, the compacted beans and the measurement of pressure all have to do with chemistry – the chemistry of the coffee beans and the chemical interactions between the beans and the hot water. The flavor of coffee comes from fats and proteins in the coffee beans. When the beans are mixed with hot water, those oils and proteins are released. The longer the water is in contact with the coffee, the more chemicals are washed out of them. If the water is too hot, the coffee can overcook and taste burnt. If it is too cold, the coffee can be watery and tasteless. If the water takes too long to get through the coffee, it can extract the more bitter tannins and other chemicals from the beans. If it doesn’t take long enough – well, you get the idea.
When water and coffee meet with all the variables at precisely the right measurements, the result is a cup of thick, rich, creamy brew with a complex flavor that resides as much in the foamy emulsion on top as it does in the liquid that sits beneath it. Every Barista has their favorite machine, their favored technique and their own method for achieving that perfect shot of espresso. What follows is just the instructions for making espresso. It’s rather like explaining the tools of painting to an artist and giving him a set of step by step instructions to create a masterpiece. It’s a starting point on which to build your own technique for making espresso.
Your technique for making espresso will also largely depend on the kind of espresso machine you’re working with. A fully automatic machine requires far less management than a semi automatic espresso machine. These are general directions for making espresso. Adjust them to fit your machine and equipment.
Preheat the espresso machine by running a blank shot through it.
Pour water into the reservoir to heat.
Measure out .25 ounces – about 1 1/2 teaspoons – of finely ground coffee into the coffee filter for one 1 1/2 ounce espresso. Use 2.5 to 3 teaspoons for a double shot.
Put the filled coffee filter on a sturdy surface. Take your coffee tamper and place it on top of the coffee in the filter. It should fit snugly into the top of the filter. If the tamper is too small, the coffee around the edges of the filter won’t be compressed, and the water will naturally flow through the grounds there, missing most of the flavor in the center of the puck. Press straight down, applying even, firm pressure. You should aim for about 30 pounds of pressure. You can get a feel for how much pressure that is by using a bathroom scale to measure your strength. Push down, twisting slightly in one direction and lift straight up. The surface of the coffee should be smooth with no crumbs. Brush away any crumbs of coffee from around the edge of the filter and place the filter into the group handle.
Twist the group handle into the group head, making sure that it’s seated firmly.
Place a warmed espresso cup beneath the spout.
When the water reaches the right temperature, turn on the pump to force the water through the coffee. The right temperature is between 192 and 195 degrees. This is one of the areas where artistry comes into play. Many baristas “temperature surf” to find the precise temperature that works best for their machine. If your machine has an indicator light rather than a temperature gauge, turn on the pump when the indicator light goes on.
The coffee should flow out of the group head like honey rather than dripping or dribbling. The first coffee through the group head will be thick and dark. It will gradually lighten until the last of the coffee is a thick froth.
Serve the espresso immediately before it has a chance to cool.
Depending on your machine, you may need to wait for it to cool and reheat before making another shot of espresso.
In general, it should take about 20 to 25 seconds for the water to filter through the coffee and into the cup. If it takes less or more time, you may have to adjust the grind of your coffee or the amount of pressure you use in tamping it.