Espresso

May 30, 2007

We will try to explain here what exactly an espresso is. Let’s look at some definitions first:

World Barista Championship rules:

A. An espresso is a one ounce / 30 ml liquid including crema, +/- 5 ml is allowed.
B. Each single espresso should be produced with an appropriate and consistent amount of
ground coffee.
C. Espresso shall be brewed at a temperature between 195-205 degrees Fahrenheit / 90.5-
96 degrees Celsius. (Refer to section 2.6 WBC Espresso Machine).
D. Machine brewing pressure will be 8.5 to 9.5 atmospheres. (Refer to section 2.6 WBC
Espresso Machine).
E. Extraction time must be between 20 to 30 seconds.
F. Espressos must be served in a 2 to 3 ounce / 60 to 90 ml cup with a handle.
G. Espressos should be served to the judges immediately complete with spoon, napkin,
sugar and water.

Espresso

This tells us mainly how an espresso should be made.

Wikipedia says:

Espresso or caffè espresso is a concentrated coffee beverage brewed by forcing very hot, but not boiling, water under high pressure through coffee that has been ground to a consistency that is between extremely fine and powder.

So, an espresso is an one ounce hot beverage that flows out from an espresso machine. It is hot water that has been forced with great pressure through ground coffee.

Producing a good espresso

A good brewed espresso is the base of many popular drinks, i.e. the Caffe Latte and the Cappuccino. Espresso’s are very popular in the southern countries of Europe. It is important to ensure that your espresso is of good quality even when you add a lot of milk. The flavours of the espresso have to cut through the milk to make sure that your Caffe Latte or Cappuccino is the best in town! Here are the basic ‘rules’ for producing a good espresso.

Espresso - naked porta filter

High quality beans
The coffee beans that are used for espresso’s are usually a blend from different origins. The espresso is such a complex drink that you need to use coffee beans from different origins to make sure that you can extract all the flavours out of the beans.

The beans that you use for espresso’s have to be of very high quality. This usually means that the blend has a high percentage of Arabica beans and a lower to none percentage of Robusta coffee beans. A good rule is not to go cheap on coffee beans.

Fresh coffee
Coffee beans should be used quickly after roasting. The beans off-gas for months after roasting. The storage of the coffee beans is very important. Coffee beans should be stored in a dark and cool environment (not in a freezer or fridge). The beans should be stored in a sealed bag with a one-way valve. This one-way valve let’s the carbon dioxide out but doesn’t let any air in. Air is the biggest enemy of coffee so try to avoid as much contact with air as possible. Temperature, moisture and light also affect the deterioration of the coffee beans.

You can keep the coffee beans in the hopper of the grinder for about 3 to 4 days but try to use them as quick as possible. It is good practise to only load the hopper with the amount of coffee beans that you need for the day. Leave the rest of the beans in the bag and seal the bag tight.

Ground coffee goes stale very quick. This is because the coffee has more surface that can connect with air. Ground coffee should be used within 2 to 4 hours. But a good rule here is to only grind the amount of coffee that you need. So called ‘Grind on Demand’ grinders grind only the coffee that you need. These grinders grind the coffee straight into the group handle and do not have a chamber to store coffee.

The right grinder setting
The grinder has two blades that grind the coffee beans. The closer these two blades are together, the finer the coffee. The further apart the two blades, the coarser the coffee. Filter and cafetiere coffee needs a coarser grind than espresso. Turkish coffee needs a very fine grind.

It is very important that you have the correct setting of the blades. You can check the right settings by looking at the extraction. The extraction of the coffee should look like a mouse tail. It should have a golden color and not yellowish or really dark brown. The extraction time should be between 20 and 30 seconds from the moment the button is pressed (World Barista Championship standard).

Extractions that are too quick are called under-extraction and extractions that take too long are called over-extraction. Under-extraction usually means that the blades are too far away from each other, the grind is too coarse.

A single shot of espresso should be made from 7 to 8 grams of coffee and a double from 14 to 16 grams of coffee. Some people prefer to use more or less coffee but these are quite good guidelines. The manual of your grinder should explain how you can adjust the dose of ground coffee.

The grind can be made finer by moving the blades of the grinder closer together. Please refer to the manual of your grinder to see how you can change the setting of the blades.

Amount of liquid from the espresso coffee machine
A single espresso should be 1 oz or 30 ml of liquid. This means that you should get 1 oz of liquid from 7 to 8 grams of coffee. It is extremely important that you don’t push any more water through that coffee and definitely don’t use the same coffee twice. You can use shot glasses (see picture) to set the right amount of liquid.

Coffee only has a certain amount of flavour to extract. Try this little experiment to see what we mean here: produce a single espresso and then use the same coffee and make another espresso. The first espresso will taste fine and the second one more like an ashtray. This shows that it is important that you don’t push too much water through the ground coffee.

A good espresso is the base for Latte Art:
Rosetta by Youri Vlag

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