Front Street Coffee can be said that steaming milk is a basic and core skill for every barista. Whether one can steam perfect milk is one of the factors for judging whether a barista's level is qualified. For example,The milk foam of a latte is on the thin side, making it smooth and delicate to drink. So when steaming milk for a latte, it should not be too thick. The steamed milk should have a glossy surface, with no obvious large bubbles or small bubbles, and should be delicate and beautiful overall.
 

The basic principle of milk foaming is to use steam to strike the milk, forcing air into the liquid milk, and using the surface tension of milk protein to form many tiny bubbles, causing the liquid milk to expand in volume and become foamy milk foam.

During the foaming process, lactose dissolves in the milk as the temperature rises, and the foaming action seals the lactose within the milk. The role of milk fat is to make these tiny bubbles form a stable state, so that when these milk bubbles are drunk, the tiny bubbles burst in the mouth, allowing the flavor and aromatic substances to be better released and amplified, giving the milk a sweet, rich taste and mouthfeel. Moreover, when blending with coffee, the binding force between molecules will be stronger, allowing coffee and milk to fully combine, so that the characteristics of both coffee and milk can each stand out while also being completely integrated, achieving a complementary effect.
　　

Front Street Coffee is here to answer some questions everyone commonly encounters when steaming milk foam!　　

Why doesn't the steamed milk foam blend?

The milk foam immediately blends with the coffee as soon as it is poured into the espresso. Forget about making a pattern—there isn't even a line, it just floats away. Or else, the blending at the beginning is fine, but when it comes to latte art, the milk foam clumps up and floats directly on top. Front Street Coffee will first explain the first situation: this is because the foaming amount is small and the steamed milk foam is thin, being mainly hot milk, so how could it form a pattern? So friends who encounter this situation should be bolder and foam a bit more!

Then why is it that although the blending is fine, the milk foam floats on top during latte art?

This is mainly because the integration between the milk and milk foam is relatively poor, so the milk and milk foam separate, and in the end the milk foam floats on the coffee. In this case, adjustments can only be made during the milk foam texturing stage!
　　

What determines the degree of integration between milk foam and milk? The degree of integration mainly depends on the following two points:

1. The size of the steam wand's air pressure. (The size of the steam wand's air pressure will cause the milk foam to roll to different degrees during steaming. The greater the air pressure, the higher the degree of integration.)

2. The fineness of the milk foam. (The finer the steamed milk foam, the less air contained in each individual milk bubble, the higher the density and the smaller the buoyancy; the coarser the steamed milk foam, the more air contained in each individual milk bubble, the lower the density and the greater the buoyancy. If the steamed milk foam is relatively coarse, the milk foam will quickly float to the surface of the milk, and the degree of integration will be lower; if the steamed milk foam is relatively fine, the milk foam will float to the surface of the milk more slowly, and the degree of integration will be higher.)
 

Why is a high degree of integration between milk and milk foam required?

The higher the degree of integration between milk foam and milk, the clearer and more delicate the lines of the latte art pattern will be; conversely, the lines of the latte art pattern will be blurrier and coarser.
　

How should the degree of integration of milk and milk foam be judged?

Front Street Coffee teaches you how to judge the degree of integration of milk and milk foam! Pour the steamed and integrated milk and milk foam into a glass and let it sit, observing the time it takes to separate. The length of the separation time indicates the degree of integration of the milk and milk foam!

If it separates within 30 seconds, it is poor; if within 30-60 seconds, it is medium; if after 60 seconds, it is excellent.

Also, do not ever leave the steamed milk foam aside to use later, as this will also cause separation!

Some people may ask, why is there a requirement for the temperature of steamed milk?

　　
Generally, Front Street Coffee heats the milk to around 60 degrees, but it must not exceed 70 degrees, otherwise the protein structure in the milk will be destroyed.
　　

Front Street Coffee previously conducted experiments, steaming milk to different temperatures:

The situation at 90°C is: when it exceeds around 70°C, even if the milk foam is not deliberately foamed, the foam will rapidly expand. At high temperatures it keeps rolling, and when it was almost 90°C, the editor's milk had already overflowed the milk pitcher (as shown in the picture above), stopping at 94°C. Obvious signs of foam dissipation had already appeared at around 1 minute 30 seconds.

The situation at 60°C is: this is the temperature we use more commonly. Steaming milk foam according to conventional operations, stopping when it feels hot to the touch, the temperature is 63°C. Obvious signs of foam dissipation appeared at around 10 minutes 50 seconds.

The situation at 30°C is: foaming according to conventional methods, the temperature felt by hand is warm, and the stopping temperature is 33°C. Obvious signs of foam dissipation appeared at around 4 minutes 20 seconds.

　
The situation at 12°C is: here we directly used milk from the refrigerator and a manual frother. The temperature when poured into the frother was 8°C, and the temperature after frothing was 12°C. Obvious signs of foam dissipation appeared at around 5 minutes 15 seconds.

Milk foam within the 50~70°C range has the best durability whether in pure milk or after being added to coffee, for two reasons: first, after steaming the milk foam there is relatively sufficient time for mixing and texturing between the milk foam and the liquid milk; second, it is in the period when the milk has begun to denature but has not yet reached irreversible denaturation, so the stability is relatively high.

When milk foam is steamed to around 80~90°C, irreversible denaturation occurs in the milk. There are two kinds of protein in milk: whey protein and casein; whey protein begins to denature above 60°C. So when we steam to around 90°C, the protein's elasticity is insufficient, so the foam dissipates relatively quickly.

When milk foam is steamed to around 30~40°C, the reason the foam dissipates relatively quickly is caused by insufficient time for mixing and texturing between the milk foam and the liquid milk after the milk is foamed.

The reason frozen milk foam dissipates quickly is that we used a manual frother, and its degree of mixing cannot compare with the integration achieved by the high-speed mixing of a steam wand. The degree of integration is not high, and in addition, during the period when it transitions from low temperature to room temperature, for the milk foam this is a heating process. Under external heat pressure, the internal gas expands when heated, so the milk foam bursts relatively noticeably.

How can Front Street Coffee produce abundant and finely textured milk foam?

Regarding how to make a good batch of milk foam, here is an foolproof milk foam method: pour half a pitcher of milk into the stainless steel pitcher, position the steam wand perpendicular to the milk either in the very center or at the edge of the pitcher, then let the steam tip just touch the surface of the milk, then open the steam to the 1/2 position, do not move the pitcher, slowly close it when the milk reaches 50 degrees, and close it exactly at 60 degrees. The final temperature will reach 66 degrees. In this way you can make a good pitcher of milk foam.
 

What type of espresso machine should be used to steam milk foam?

Generally, machines have three-, four-, and five-hole steam tips. As long as you become somewhat familiar with them, you can steam good milk foam. However, the machine's steam output, the dryness or wetness of the steam, and the size of the steam holes still affect milk steaming.

　　
Why practice steaming milk foam with water?

First, as everyone knows, water is transparent, which allows you to see more clearly how the vortex is formed.

Second, it allows you to better master the steaming method for different numbers of holes! Third, beginners must remember that when you are not yet able to steam milk foam to a silky consistency, you should use a thermometer. If you cannot better control the temperature, then the coffee you make will be unstable. Perhaps out of ten times you may steam good milk foam once or twice, but that is not stable quality.
　

The difference between steaming milk with steam and frothing milk by hand

　　
First of all, hand-frothed milk foam simply cannot compare with machine steam. The fineness of steam makes the milk foam it produces very fine and silky. Steam has a wide radiation area, so the milk foam produced is relatively even and blends relatively well. Hand frothing mainly relies on pressing through the small holes of a filter screen, so the milk foam produced is relatively coarser.
 

How does Front Street Coffee make milk foam?

Method One: Make handmade milk foam with a milk frother / French press

1. Pour milk into the milk frother, and the amount should not exceed 1/2 of the milk frother, otherwise the milk will overflow due to expansion when making the milk foam.

　　
2. Heat the milk to around 60 degrees, but it must not exceed 70 degrees, otherwise the protein structure in the milk will be destroyed. Note! The lid and filter screen must not be heated directly. (If making iced milk foam, cool the milk to below 5 degrees. Of course, do not chill it too much and let the milk freeze.)

3. Put on the lid and filter screen, and quickly pump the filter screen to press air into the milk. When pumping, there is no need to press all the way to the bottom, because the goal is to beat air into the milk, so just move it at the surface of the milk; there is also no need to do it too many times, gently pumping about thirty times is enough.

4. Remove the lid and filter screen, and use a spoon to scrape off the large coarse foam on the surface. What remains is dense hot (iced) milk foam.

Method Two: Make milk foam with a steam milk frother

First, do not insert the steam wand into the milk yet, because there may be some condensed water in the steam wand, so first release some of the steam from the front section, and at the same time discharge the excess water.

Insert the thermometer into the container, then insert the steam wand diagonally into the milk, and turn on the steam switch.

Slowly adjust the position of the steam nozzle to just a little bit away from the surface of the milk, but never above the liquid surface, otherwise the milk will splash everywhere. When the position is correct, you will hear a steady "hissing" sound; otherwise it will be very loud or almost silent.

When there is enough milk foam, you can bury the steam wand a bit deeper and let the steam continue to heat the milk. The best angle for burying the steam wand is just enough to make the milk rotate.

When the temperature reaches between 60°C and 70°C, you can turn off the steam switch.

Use a wet cloth to wipe clean the milk attached to the steam wand, and at the same time release some steam again, so that the milk does not become difficult to clean after it dries.
 

Tips for testing temperature by hand when steaming milk foam:

1. The most suitable temperature for milk foam

When milk is foamed on a coffee machine, the most suitable temperature is controlled within the range of 55~65 degrees, for the following reasons:

　　
1. If the milk temperature is below 60 degrees, it will lower the temperature of the coffee a lot and affect the taste;

2. The lactose in milk between 55~65 degrees will be brought out, making the coffee more fragrant, sweeter, and smoother.

　　
3. For milk above 70 degrees, the nutrients in it will be destroyed. After all, the milk will become more watery, and the smoothness and sweetness will both deteriorate.
 

2. Tips for testing temperature by hand when steaming milk foam

Now that we know the most suitable temperature for milk is between 55~65 degrees, how do we master this temperature? My personal suggestion is that you need to equip yourself with a thermometer. You can directly insert the thermometer into the foaming milk, so the temperature of the milk will be clear at a glance. Of course, with accumulated experience, in the end you can also do without the thermometer and directly rely on your hand to sense the temperature of the milk foam.

The techniques are as follows:

1. Hold the milk pitcher with your left hand, turn on the steam with your right hand, and begin foaming the milk;

2. After turning on the steam, place your right hand back against the wall of the milk pitcher to feel the temperature of the milk foam;

3. When your hand feels very hot and you can no longer keep it against the pitcher, stop foaming the milk, then insert the thermometer into the milk foam and measure the temperature.

4. If the temperature has not reached the range of 55~65 degrees, it is suggested that next time when it becomes hot to the touch, you can move your palm away and begin counting silently in your head 1, 2, 3, 4, usually in seconds, to add time. For example, after you move your hand away from the milk pitcher, if after adding four seconds the measured temperature reaches 65 degrees, then congratulations, you have found the pattern. From then on, just add about four seconds each time it becomes hot to the touch. By adding or subtracting time according to point 4 above, you can easily master the technique of testing milk foam temperature by hand. The above techniques are somewhat of a shortcut. Actually, as long as you steam milk foam for a period of time, you will more or less find the pattern and the feel, and the temperature of the milk foam will also be easier to control.

Five major misunderstandings about steaming milk foam
 

Regarding milk foam, there are several misunderstandings we need to understand, so that we can better understand milk foam.

Misunderstanding One: Using up-and-down shaking of the latte art pitcher to remove the coarse foam on the surface. This is a very good method, but many friends have developed a strong dependence on this method. If their milk foam is not steamed well, they do not summarize why it was not steamed well, but instead use this method to compensate. Over time, dependence develops. Front Street must say here that if you rely only on this method to remove coarse foam, your milk foam technique cannot improve, and you also cannot practice advanced latte art techniques.

Misunderstanding Two: Using a spoon to scoop away the coarse foam on the surface. Front Street does not recommend this method. Although some competitors use this method in competitions, Front Street believes this is because their milk foam technique is not up to standard, with too much coarse foam on the surface that cannot be shaken off, so they can only scoop it. Anyone who uses similar methods to handle milk foam should definitely strengthen their steam control technique when steaming milk foam.

Misunderstanding Three: After steaming the milk foam, leaving it aside to sit for a little while. This method is very troublesome. This is a manifestation of milk foam technique not yet having even entered the door. It will intensify the separation of the milk foam, and the integration of hot milk and milk foam will be very difficult to complete. If you are not careful, it becomes milk as milk and foam as foam. The whole cup of coffee has no balanced taste.

Misunderstanding Four: When pouring back and forth between two latte art pitchers, keeping them at a very high position. The original purpose is integration, but instead it stirs up more coarse foam.

Misunderstanding Five: Blaming the steam when the milk foam is not steamed well. Front Street believes that a coffee machine steam pressure (that is, boiler pressure) of 0.8 BAR is a relatively easy-to-master air pressure for steaming milk foam. At this pressure, steaming milk foam is very prolonged, and it is also easy to understand the principle of milk foaming, but making a pitcher of milk foam takes about 13 seconds. Ha, it is not as fast as high pressure. If the pressure is 1.0 or 1.1 BAR, then the ways and methods of steaming milk foam will change somewhat, but the principle is the same. (This point excludes the "spitting" phenomenon caused by impure steam, which also makes the latte art pitcher shake badly. If this phenomenon occurs, please empty the steam and try fully heating it once more.

When making complex patterns, the most important thing is to have a pitcher of high-quality milk foam, and the temperature of the milk foam is a key factor affecting the quality of the milk foam.

Front Street Coffee is here to share with everyone the method for making tulip latte art:
First, you still have to extract the espresso. Front Street Coffee uses its own Front Street Sunflower Warm Sun espresso blend beans.

Espresso part 

Coffee bean information

Extraction parameters

How Front Street makes tulip latte art
 

1: Integrate until four-tenths full, choose a point at the one-third position for pouring, and keep the latte art pitcher against the edge of the coffee cup.

2: Slowly move to the center position, paying attention to just gently swinging left and right.
 

3: When the textured pattern flows back, reduce the flow rate and speed up the swinging, paying attention to the amplitude of the swing.

4: Raise the latte art pitcher. This step is similar to the leaf pattern.

5: Pour again at the one-third position, paying attention to the flow rate and the height of the latte art pitcher, then push forward, paying attention to the pattern changes at the arrow position.

6: Push until the pattern is surrounded, raise the latte art pitcher, and finish with a thin stream, which will create a small gap.

7: Pour again, grasp the flow rate well, keep the spout of the latte art pitcher on the surface of the coffee liquid, push forward, and pay attention to the small gap in the previous forward-pushed pattern.

8: When the "petal" is surrounded by the previous "petal," raise the latte art pitcher and finish with a thin stream, again leaving a small gap.
 

9: Pour again, swing slightly left and right, pause, and form a small heart, paying attention to the change in the gap at the black line position.

10: Raise the latte art pitcher and finish with controlled flow rate.

　　
11: You can clearly see how the "petals" are formed. When finishing, be sure to pay attention to the flow rate.

The textured tulip is not particularly difficult, and it is also quite suitable for practice. Watch the video a few more times to understand the formation and changes of the pattern, as this will be relatively helpful for latte art practice. When practicing, pay attention to the amplitude of the swing. There is no need to go too fast, and there is no need to worry about too little texturing. You can also just push forward twice. Once you are proficient, you can appropriately add some texturing and push forward a few more times, which can make the pattern look even better.

For more specialty coffee beans, please add the private WeChat of Front Street Coffee, WeChat ID: kaixinguoguo0925

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