What Coffee Beans to Use for Espresso? Yunnan Blend Extraction Characteristics and Water Ratio? How to Make Latte?

Although more and more people are paying attention to single-origin coffee these days, based on the ordering situation at FrontStreet Coffee, espresso coffee still accounts for the majority of output. This is simply a matter of preference trends and doesn't represent that espresso coffee is superior to single-origin coffee, or that people who drink espresso don't understand single-origin coffee. FrontStreet Coffee has always believed that coffee is a highly inclusive culinary culture. It can simply showcase the flavors of a single origin, or it can blend multiple origins to present comprehensive flavor characteristics. When it comes to blending origins, we have to mention the most common blended coffee beans in espresso coffee. Today, FrontStreet Coffee will discuss an espresso blend from the perspectives of origin selection, roasting, and blend ratios.

What are espresso coffee beans? What coffee beans are suitable for espresso?

Espresso coffee beans mostly refer to blended coffee beans. What is blending? It's mixing various single-origin coffee beans together, typically with two or three coffee beans being more common. FrontStreet Coffee currently offers several espresso coffee beans that use both two-bean and three-bean blending methods.

The purpose of blending is quite obvious—it's to gather the flavors of different coffee beans together to present a completely new flavor profile, achieving a more balanced effect. For example, if one coffee bean is smooth but lacks aroma, you can add another bean rich in aroma to complement each other's strengths and weaknesses. FrontStreet Coffee believes it's precisely this complementary nature of espresso coffee beans that makes them more widely accepted by the public.

Espresso Blend Coffee

Espresso blend coffee roasting is generally divided into two schools: one prefers to blend first then roast, while the other roasts each origin separately before blending. These two different methods naturally result in different flavor profiles.

FrontStreet Coffee has found that blending green beans first then roasting results in more uniform color and more consistent flavor presentation, making this method more convenient. When using the roast-first-then-blend method, you need to already understand the different characteristics of various origins, including their hardness and moisture content, and adjust the roasting process accordingly. Roasting first then blending is equivalent to a one-on-one mode, presenting the unique flavors of each coffee bean one by one, with richer layers than the former method, but it also challenges the roaster's understanding of the beans.

Espresso Blend Coffee Bean Recipes? What coffee beans are suitable for espresso?

What coffee is suitable for espresso? FrontStreet Coffee currently has four different flavored Frontsteet espresso blend coffee beans.

1. Frontsteet Premium Espresso Blend Coffee Beans

Selected from Colombian and Brazilian coffee beans blended in a 3:7 ratio to meet daily café needs.

Flavor characteristics: Comfortable bittersweet taste, extremely smooth entry, with a faint grassy aroma, fresh and slightly bitter, sweet and smooth, with a pleasant aftertaste.

2. Frontsteet Sunflower Warm Sun Espresso Blend Coffee Beans

Selected from Frontsteet Honduras Sherry and Frontsteet Yirgacheffe Red Cherry blended in a 7:3 ratio.

Flavor characteristics: Obvious fruit acidity, with faint berry aroma lingering, rich wine and chocolate flavors, comfortable sweet aftertaste.

3. Frontsteet Commercial Espresso Blend Coffee Beans

Selected from Colombian, Brazilian coffee beans and Robusta in a 3:6:1 ratio, suitable for daily café production.

Flavor characteristics: Richer crema, classic taste, with caramel sweetness, nutty and cocoa-like, dark chocolate flavors, balanced sweet and sour, slightly bittersweet, with lasting aftertaste.

4. Frontsteet Basic Espresso Blend Coffee Beans

Selected from Yunnan and Brazilian coffee beans in a 3:7 ratio, suitable for café and home users who prioritize cost and have moderate flavor requirements.

Flavor characteristics: Gentle fruit acidity, caramel sweetness, nutty and dark chocolate flavors, smooth and thick, but taste is relatively light.

What is Latte Coffee?

The "latte" in latte coffee is transliterated from the Italian "latte," meaning "milk." Latte coffee can be literally understood as "milk coffee." Every coffee shop has slight differences in milk-to-coffee ratios, bean selection, extraction parameters, etc. However, under normal circumstances, latte coffee is a coffee beverage made with a large amount of milk mixed with espresso.

Many friends privately message FrontStreet Coffee asking what one needs to learn to become a barista, and whether knowing latte art is enough to become a barista. In fact, becoming a barista requires not only knowing how to make coffee but also learning a lot of coffee knowledge. Among these, the most basic skills are of course espresso extraction and milk steaming. Many cafés test barista candidates using latte coffee as the assessment topic to determine whether they possess basic barista skills.

How does FrontStreet Coffee make latte coffee?

FrontStreet Coffee uses its own Frontsteet Sunflower Blend beans for demonstration. The coffee bean information is as follows:

Coffee name: Frontsteet Sunflower Warm Sun Espresso Blend Coffee Beans
Blend source: Frontsteet Honduras Sherry Barrel & Frontsteet Natural Yirgacheffe Red Cherry
Composition ratio: 7:3
Flavor description: Vanilla, cream, fermented notes, wine notes, chocolate

Espresso Extraction Parameters:

Coffee dose: 18 grams
Coffee liquid output: 36 grams
Extraction time: 28 seconds

Milk Parameters:

Milk type: Whole milk
Steaming temperature: 50 degrees Celsius
Foam thickness: 1cm
Milk to coffee ratio: 1:9

Cup Details:

Cup capacity: 200ml
Material: Ceramic

How to make good espresso extraction?

1. Choose beans

FrontStreet Coffee generally recommends letting espresso beans rest for about ten days. But everyone knows that dark-roasted beans degas faster than light-roasted ones, so why do we recommend such a long resting period? This is because when making espresso, unlike pour-over, there isn't enough space for the coffee to degas. If the coffee beans are too fresh, degassing will be vigorous, which can easily lead to channeling, resulting in unstable espresso extraction.

2. Adjust grind size

With suitable coffee beans ready, we need to look at the espresso grind size! This is basically something that needs to be done daily—adjusting the grind. The grind size for espresso isn't fixed at a single setting. When should you adjust the grind size?

Situations that may require grinder adjustment:

1. Sudden changes in temperature, air pressure, or humidity: Especially obvious in open spaces.
2. When replacing old coffee beans with new ones: When one bag of coffee beans is used up and new, freshly opened beans are added. Because newly opened coffee beans may have different roast dates, batches, or resting periods, leading to different extraction situations.
3. Continuous brewing: After 5-6 consecutive shots, the grind may suddenly become much finer. This is because continuous use of the grinder transfers motor heat to the burrs, plus heat generated by friction between the burrs and coffee beans, causing the upper and lower burrs to expand due to heat, making the gap smaller.

The moisture and storage time of coffee beans are constantly changing, and grinder burr wear also changes over time, so baristas should regularly adjust their grinders to ensure the ground coffee powder remains perfect.

When coffee beans enter the grinder, the blades inside crush the beans into powder. The smaller the distance between the blades, the smaller the particles the coffee beans will be ground into. The finer the ground particles, the more compact and dense they become, making it more difficult for water to pass through, thus significantly extending extraction time. Conversely, if the distance between blades increases, the ground particles become coarser, water passes through more easily, and extraction time becomes faster.

Generally, we use the previous extraction parameters to make a shot of espresso, controlling the time within 25-30 seconds, with single doses of 13-14 grams and double doses around 20 grams.

After excluding factors like puck perforation, if extraction time becomes longer, it might be surface over-extraction with under-extraction inside,表现为 sharp acidity, burnt bitterness, and astringency. In this case, the grind might be too fine, and you can adjust it slightly coarser. However, if the coffee flow becomes faster, the water flow is thick, extraction is light, and the color appears pale, the grind might be too coarse, and you can adjust it slightly finer.

3. Dosing

Dosing is the first step in distribution. Uneven dosing can greatly mislead and affect the subsequent distribution steps. Even with advanced distribution tools, you cannot completely ignore the impact of dosing on espresso extraction.

What are the effects of uneven dosing?

1. Flavor differences: If dosing is uneven, it's impossible to remedy the distribution of the lower powder layer during distribution. Uneven density distribution in the powder layer leads to uneven puck thickness and different water flow speeds through different positions during extraction. Slight carelessness can easily lead to perforation or channeling (water's inertia makes it choose easier paths to pass through, ignoring other routes), causing parts of the puck to be under-extracted and parts over-extracted, making each coffee's taste unstable.

2. Large discrepancies in extraction parameters: Leading to spending a long time adjusting the grinder, with incorrect flow rate, incorrect time, and still incorrect grind size, wasting a lot of coffee beans while still unable to achieve stable output.

So how to practice dosing?

1. Prepare a digital scale
Weighing each dose before extraction is essential for making perfect espresso. Even with a dosing grinder, I recommend regularly checking the accuracy of your grinder's weighing, as even the most advanced machines can have errors and malfunctions.

2. Rotational dosing
Whether using manual dosing or direct output, as long as the coffee grounds don't fall completely vertically, the influence of lateral acceleration will cause some degree of bias in the powder layer. For example, when manually dosing, the effect of forceful versus gentle dosing is different—the more force, the more it leans to the left.

At this point, you need to maintain even dosing while uniformly rotating the portafilter to ensure the powder is evenly distributed to different positions in the basket—of course, absolute uniformity is impossible, but it's much better than fixed-position dosing.

4. Distribution

Common distribution methods include the following:

First, Scraping Distribution Method

Scraping distribution has three great tools: bean hopper lid, bamboo strips, and fingers. Scraping distribution is one of the most common and earliest methods beginners encounter, usually combined with back-and-forth movements, divided into four-way scraping (front, back, left, right) and 360-degree rotational scraping.

Second, Light Tapping and Gentle Knocking Distribution Method

Light tapping and gentle knocking are two actions but are usually used consecutively. Quickly tap the bottom of the portafilter with your palm to shake the powder pile evenly, then supplement with vertical gentle knocking to effectively eliminate large gaps in the powder layer, making the coffee powder pile denser while increasing the amount of powder that can fit in the basket.

Third, Tool-Assisted Distribution Method

When it comes to tool-assisted distribution, various methods emerge. Based on various tools on the market, they mainly fall into several categories: ① Stirring or shaking; ② Smoothing the surface; ③ Sieve dispersion; ④ Rotational distribution.

Distribution Effect Check

If during the extraction process you find that the coffee liquid flow state quickly becomes unstable, with large fluctuations and the color quickly becoming very light, you can judge: there are problems inside the puck (cracks) or uneven tamping causing areas with less coffee powder to be over-extracted (which is often caused by uneven distribution), or simply uneven distribution where edge areas aren't covered by coffee powder, causing water to flow directly through there.

After extraction is complete, remove the portafilter and observe the puck shape. If the edges have no coffee powder, or the coffee powder is floating, or the puck has obvious gaps, then the extraction failure was caused by uneven distribution.

Fourth, Tamping

Tamping is applying pressure through a certain force to compact loose coffee powder so that pressurized hot water can penetrate evenly.

The direction should be vertically downward. If you tamp at an angle, the high-temperature, high-pressure hot water from the group head will seek the path of least resistance to penetrate, causing uneven extraction. At the same time, it easily leads to what we commonly call channeling.

The amount of tamping force and what tamper you use don't have much relationship, as long as you compact the powder. Therefore, maintaining consistent tamping force each time is more important.

How to foam milk?

How can you create fine, dense milk foam, which is essential in lattes? FrontStreet Coffee recommends using whole milk with 3.2-3.8% fat content.

For this experiment, FrontStreet Coffee used Kowloon Dairy fresh milk.

Milk Steaming Process

1. Place the steam wand at the center point of the milk pitcher, tilted 45 degrees to the upper right against the pitcher edge, at a depth of about 1 cm. (This depth is quite common, but面对咖啡机蒸汽强度不一, this is just a suggestion.)

2. Open the steam wand steam, slowly move the milk pitcher downward, and make the steam wand air vent contact the milk surface to create aeration effect, presenting an up-and-down flipping motion to slowly let the volume expand and foam.

3. When the aeration and expansion reach your desired thickness, tilt the steam wand to the center point of the pitcher near the steel cup edge, making the milk foam present a vortex rolling motion.

4. Control the steel cup angle and depth to fold in coarser foam, stopping when reaching the desired temperature.

Milk Steaming Principles

The first stage is: Stretching/Aeration - stretching is when the steam wand air vent contacts the milk surface, and steam enters the milk to stretch it into foam.

The second stage is: Texturing - texturing is using vortex motion to fold air into the stretched milk, causing larger bubbles to break down into fine foam, and creating adhesion between milk molecules to make the foam texture more dense.

Points to Note

Stretching, Aeration

Open the steam to begin aeration, observe the milk surface. If the milk is rotating without hearing the "chi-chi-chi" sound, it means air isn't being incorporated. At this point, you need to lower the milk pitcher slightly to expose the nozzle a bit for air intake. When you hear the "chi-chi-chi" sound of air intake, stop lowering the pitcher and keep it in place.

At this point, observe the milk's movement state. Under normal circumstances, it should be aerating while the liquid rotates, forming a vortex.

The action of lowering the pitcher for air intake must be subtle and gradual, not too forceful. When the sound indicates air is being incorporated, stabilize and stop lowering.

Steam Wand Angle When Foaming Milk

Many people are accustomed to placing the steam wand at the 2-3 o'clock or 9-10 o'clock position of the milk pitcher (taking the pitcher spout as the 12 o'clock direction).

In addition to placing the steam wand in the correct position, the angle between the steam wand and the liquid surface is also very important.

If the steam wand is too vertical, most steam sprays downward, making it difficult for the milk to form a small vortex. If the steam wand is too horizontal, most steam will spray in a parallel direction, making the small vortex too large and creating turbulence that's hard to control or causing milk to overflow.

Beginner Latte Art Practice Methods

When we've extracted a shot of espresso and prepared the milk foam, first shake the cup in a circular motion to make the crema adhere to the cup walls, then tilt the cup at about 40 degrees.

When pouring the milk, control the stream to not be too large, allowing the milk to penetrate directly through the coffee liquid to the bottom layer, then begin circling to mix the milk and coffee liquid.

What needs attention here is that the milk stream should be fine when pouring, and it should be positioned in the center of the coffee liquid. As shown below:

Then begin circling to mix the milk and coffee liquid until about six-tenths full before starting the latte art.

Push Layer Heart Latte Art

For push layer heart, pour milk at the 1/3 position of the cup, pushing out a semicircle, then immediately push forward another one. When forming the final heart shape, raise the pitcher height and pour for a moment to let the initial semicircle surround the entire heart, finally use a thin stream to finish.

Frontsteet Latte Coffee Flavor Description

FrontStreet Coffee's current espresso blend is the Frontsteet Sunflower Warm Sun Blend Coffee Beans, made from Frontsteet Honduras Sherry Barrel fermented processed beans blended with Frontsteet Ethiopia Yirgacheffe Red Cherry Project natural processed coffee beans. This blend's espresso combined with milk presents obvious liquor-filled chocolate, with noticeable sweetness, long and clean aftertaste, making it very suitable for friends who enjoy wine-flavored profiles.

For more specialty coffee beans, please add FrontStreet Coffee on private WeChat, WeChat ID: kaixinguoguo0925

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473