What makes espresso coffee beans extraction qualified?

Espresso is the concentrated base for lattes, cappuccinos and mochas, made by forcing nearly boiling high-pressure water through finely ground coffee. A qualified shot is defined by its extraction standards and dose rather than volume alone. Single and double shots differ mainly in the amount of ground coffee used and the resulting strength in the cup.

The production process covers grind size, pressure and time, with crema and dissolved solids as visible markers. Modern practice weighs the dose in grams instead of measuring milliliters. For a hot latte, specific parameters are given on the Feima E98 machine, along with suggested milk-to-coffee ratios for balanced flavor.

Espresso is the soul base of fancy coffee drinks like lattes and cappuccinos, but many friends who are just getting into coffee still have doubts about its definition, extraction standards, and the difference between single and double shots. Based on the production experience of Front Street Coffee, this article systematically sorts out the basic concept of Espresso, the differences between single and double shots, the production process and qualified standards, and combines the Feima E98 coffee machine to give specific extraction parameters for hot lattes and suggestions on the milk-to-coffee ratio. Whether you want to know how many milliliters an espresso must be to count as qualified, or want to know why grams are now mostly used for measurement, this article can provide clear and practical answers to help you build a basic understanding of espresso.

Nowadays, espresso mostly appears as the base for fancy coffee drinks, with lattes, cappuccinos, and mochas being typical examples. The flavor differences among them mainly come from the different ratios of espresso to milk. Some drinks use only a single shot of espresso, while others use a double shot. So what exactly does a double shot mean? And what is the volume of a cup of espresso? Next, Front Street Coffee will explain this one by one for coffee lovers.

What is espresso?

Espresso, also called Espresso, is a drink made by forcing nearly boiling high-pressure water through finely ground coffee powder. Compared with other extraction methods, Espresso is usually more intense, with a higher concentration of suspended particles and dissolved solids, such as the creamy layer of crema on the surface.

Because pressure is applied during production, Espresso has a strong taste impact, and the concentration of chemical substances in it is also quite high. For this reason, it is often used as the base for lattes, cappuccinos, mochas, and Americanos. However, at Front Street Coffee, many coffee lovers also prefer to directly order an espresso and carefully appreciate its rich and smooth mouthfeel.

From the name, it can be seen that espresso came from the Italians. At that time, intense and bittersweet espresso was popular in Italy, while single-origin coffee often leaned toward one extreme in flavor, with both strengths and weaknesses existing at the same time. In addition, high-quality single-origin coffee beans were expensive, so Italians mostly used blended beans to make espresso and continued to research and innovate on this basis up to today.

The difference between single and double espresso

According to Front Street Coffee, the difference between single and double espresso is mainly reflected in concentration. Taking Front Street Coffee as an example, a single shot uses about 10 grams of coffee powder, and a double shot uses about 20 grams of coffee powder, but the final volume of coffee liquid is 30 milliliters for both. A single espresso uses a single portafilter basket and a single-spout handle, extracting one shot at a time; a double espresso uses a bottomless basket or bottomless handle, extracting a double shot at a time.

However, according to Front Street Coffee, beneath the foam, espresso is actually tiny oil droplets in which sugar, acids, proteins, and caffeine are dissolved, and bubbles and solid solutions are also suspended on the surface of the foam. Therefore, the degree of wear on the grinder blades will gradually change with humidity and storage time, and the grind size needs to be adjusted every day to ensure stable espresso flavor.

Espresso production process

Espresso is made by forcing high-temperature, high-pressure water through very fine or slightly fine coffee grounds. The key is that finely ground coffee powder allows coffee components to be extracted quickly and in large amounts, while being evenly penetrated by high-pressure hot water. This process extracts the solids and soluble components in the coffee, ultimately forming a drink with a texture close to syrup. Crema is produced when the oils in the coffee powder are emulsified into a colloid, which does not occur in other coffee production processes.

According to Front Street Coffee, there is no unified standard for the Espresso production process, but some publications have attempted to regulate the roast level of ground coffee, powder weight, extraction water temperature, extraction speed, and even tamping weight, resulting in great differences in espresso production methods across regions. Making an espresso is usually called "pulling a shot." This expression comes from early lever-style espresso machines, because it was necessary to pull down the handle on the spring piston to force hot water under high pressure through the coffee powder. Today, however, most espresso machines rely on electric devices to generate pressure.

How many milliliters does a shot of espresso need to be to qualify?

So how many milliliters does a shot of espresso actually need to be to qualify? The common international technical standard is: about 7 grams of freshly ground coffee powder, using water at about 92 degrees Celsius and pressure at about 9 bar, extracted over 20 to 30 seconds to obtain a cup of about 20-30 ml of coffee, with the surface covered by a layer of crema.

As coffee becomes more specialty-oriented, some new coffee theory knowledge has been disclosed, and with many independent cafes flourishing, espresso extraction plans also have subtle differences. According to Front Street Coffee's standard production, a cup of espresso is based on 2 shots (1 serving of espresso), using 19 g of coffee powder, extracted at a 1:2 ratio to obtain 38 g of espresso liquid, in 28 seconds.

Why do most coffee shops in China nowadays no longer use milliliters as the standard for extraction parameters, but instead use grams? This is related to density. What you can see in a cup of espresso is the dark coffee liquid and the crema floating on top, and this crema has low density and large volume, and it cannot be guaranteed that the crema in every cup will be completely consistent, so using weight measurement is more precise.

A single shot uses about 10 grams of coffee powder, and a double shot uses about 20 grams of coffee powder, but the final coffee volume is 30 milliliters for both. A single espresso uses a single portafilter basket and a single-spout handle, extracting one shot at a time; a double espresso uses a bottomless basket or bottomless handle, extracting a double espresso at a time.

However, according to Front Street Coffee, beneath the foam, espresso is actually tiny oil droplets, dissolving sugar, acids, proteins, and caffeine, and bubbles and solid solutions are also suspended on the surface of the foam. Therefore, the degree of wear on the grinder blades will slowly change with humidity and storage time, and the grind size must be adjusted every day to ensure stable espresso flavor.

So how many milliliters a shot of espresso needs to be to qualify mainly depends on the coffee-to-water ratio. Next, Front Street Coffee will share the parameters and process for making a hot latte.

The ratio for making latte coffee

Front Street uses the Feima E98 espresso machine, and the extraction parameters are as follows:

Pressure: 9 bar

Temperature: 90.5~96 degrees Celsius

Time: 25~30 seconds

Coffee-to-water ratio: 1:2

Dose: 12g (single espresso) 20g (double espresso)

Extracted espresso amount: 20ml (single) 40ml (double)

Front Street uses a double espresso to make latte coffee, using Front Street. Front Street Classic Blend Espresso Coffee Beans, which combines three major origins: Costa Rica, Colombia, and Ethiopia, with aromas of roses, citrus, grapes, and dried blueberries, making Americano taste as sweet and fresh as fruit gummies.

Milk: whole fresh milk (Front Street uses Vitasoy fresh milk)

Milk steaming temperature: 50-60 degrees Celsius (too low a temperature cannot stimulate the release of lactose in milk, too high a temperature will destroy the protein in milk, resulting in a gritty mouthfeel)

Milk foam thickness: 1 centimeter (milk foam thinner than 1 centimeter is for making Australian white coffee, and milk foam thicker than 1 centimeter is for making cappuccino)

Recommended ratio for hot latte coffee

Front Street recommends a coffee-to-milk ratio of 1:6.5 for making latte coffee, that is, 40ml espresso with 260ml hot milk. By fully blending the milk and espresso in a circular motion, you can get a cup of hot latte.

After fresh milk is heated, the sweet molecules of lactose are better released. After being evenly mixed with espresso, the whole cup of latte naturally has the sweetness of milk without stealing the spotlight from the espresso. Instead, with the support of milk, it better reflects the flavor of the espresso. The flavor performance of Front Street's hot latte is: dark chocolate, caramel, butter, with lactose and coffee acidity colliding to create a milkshake-like sweetness, and the finish is a nutty aftertaste like hazelnut.

The above content is compiled by CoffeeHunters, a coffee news website.