What is espresso？
Espresso originated from the coffee culture of Italy, is a kind of coffee loved by Italians. In Italian, Espresso means “fast” and “pressure”, because it is the extremely concentrated coffee essence extracted under the steam pressure of the Espresso machine under high pressure, with a total of about 30-45cc, so it is called “Espresso”.
Espresso is not only the base of all fancy coffees, it can be blended with milk and cream to make colorful fancy coffees, but also has its own flavor when drinking directly.
What’s so special about Espresso?
Espresso is generally divided into single and double .
Strong and intense. The strong bitter taste goes straight to the tongue embryo, but in a moment a variety of rich flavors will also emerge and fill the whole mouth. Tasting a cup, endless mellow fragrance is continuous, bitter taste disappeared and left a variety of subtle taste mainly based on sweetness, which makes you exciting and happy. After drinking, even the bottom of the cup contains sweet.
What kind of Espresso is good?
A cup of standard espresso, is supposed to balance the flavors, with a smooth and a mellow taste without bitterness.
To be professional, it contains moderate sour taste, bitter taste, sweet taste, solid mellow feeling, and makes people feel like tasting liquor, the flavor lasting for a while.
Espresso is a test for barista
It is one of the main iterms in the world barista competition.
Espressoat the WBC,World Barista Championship requires the following criteria：
- The volume of a cup of Espresso is one ounce(25-35ml containing crema)
- A cup of Espresso is made from a few grams of coffee(usually depending on grams and propotion)
- The water used for brewing is between 90.5 and 96 degrees Celsius (195-205 degrees Fahrenheit)
- The extraction pressure of Italian coffee machine is between 9 and 15 atmospheres (9 is the international standard, different coffee machine has errors)
- The best time to brew is between 20 and 30 seconds, but it is not mandatory (20-28 is common)
- For the same drink, the difference in brew time must be less than 3.0 seconds
- Espresso must be served in a 60-90ml (2-3 ounce) handlebar cup
- Espresso should be served with a coffee spoon, paper towel and water.
A cup of standard Espresso
- Observe color: crema color, color likability, grease thickness, extension. (usually dark yellow or reddish)
- Smell of the wet sweet: aroma of caramel, nutty, (common aroma)
- Taste: sweet, sour, mellow, aftertaste, etc., especially to pay attention to experience the bitter taste
Common drinking ways of Espresso
- Quick drink: concentrated in 35-45cc, it can be drunk in one gulp.
- However, it is generally recommended to drink it in two bites, the first to feel the impact, and the second to feel the full flavor
- Warm drinks with sugar
- It is generally recommended to add sugar cubes, but personally it is recommended to add syrup directly, because sugar cubes take time to melt, and Espresso is recommended to drink within 30 seconds, so adding syrup allows us to avoid bitterness and taste its strong flavor at the same time.
How to make a cup of relatively standard espresso, we first need to understand the details of a good cup of espresso.
Problem1： Degree of coffee grinding
Under normal circumstances, a cup of espresso extraction time of 20~30 seconds is an ideal extraction time
There will be a slight difference between different machines and grinders.
- Over coarse grinding：
- It’s too fast to extract more than 45 milliliters of coffee fluid in 20 seconds. The concentrated color is light yellow, the texture is thin, the crema is scarce and the maintenance time is very short; It has high acidity, simple taste and strong bitterness。
- Excessive grinding：
- The flow rate is very slow, > 30 seconds extraction time, can extract the desired milliliter of coffee liquid; but it was dark brown and thick. Bitter taste, strong irritation. (normal extraction, concentration) the concentrated liquid will flow out after 3-5 seconds.
Every day when we open a bar, we have to make a cup of espresso to see if the flow rate is normal and if we need to adjust the grinder.
Problem2：Powder quantity problem：
- Too much powder: the flow rate is too slow, even the handle can not be pressed on the boiling head.
- Too little powder：the velocity is too fast, the extracted powder cake is like a slurry. The reason is that the water will be too large space between the blanching head and the powdery cake, and the water shock during the extraction makes the powdery cake roll. The ideal amount of coffee powder is the powder hammer to crush the powder into a horizontal line with the powder bowl。
- About the choice of the powder bowl：
- It is recommended to use double powder bowl as far as possible. Compared with single powder bowl, the successful extraction rate is higher and the production is more stable
- Know the capacity of your coffee bowl. For example, the carrying capacity is 18 grams (normal quantity). It is recommended to use powder quantity to choose between 16 and 18 as the ideal quantity.
- About Espresso grams：
- Some people concentrate by looking at milliliters, some by looking at grams, and I personally prefer grams. Although coffee is liquid, milliliters are taken for granted as a measure of the volume of liquid in coffee.
- But the crema is a big factor to be reckoned with. Milliliters are not accurate enough to measure the amount of carbon dioxide removed from the bean’s crema over time. (the more crema, the fresher the beans are .)
- Brewing time
- The time to stop extraction is also an important factor in determining the final taste of a concentrated glass. When the color of the coffee solution becomes noticeably lighter, the flow of water trembles and the flow rate increases, it is time to stop the extraction immediately. At this point, the extractable substances in the coffee are almost completely extracted.
- Excessive extraction results in bitter, astringent, woody fiber flavors that destroy the concentrated flavor of the cup. So choosing when to stop is also very important.
- The proper time is between 20s-30s.
In addition to summarizing the above variables, you can also try the elimination method
For example, if the flow rate is too fast, but you don’t know whether the component is too small or too coarse, change one of the variables and either add powder or fine grind. Change the variables one by one and check the reasons one by one. (this is very important in daily operation, and it is an indicator to adjust the grinding degree every day.)）
Record. Recording the parameters of each adjustment, such as powder weight, grinding degree, extraction time and coffee liquid weight, is very helpful for beginners to form a clear extraction scheme, and can be understood and mastered as soon as possible.