Barista skills "Professional barista Handbook" (5) how to play milk foam?

Chapter IV Milk

Get rid of the milk

Milk is the main ingredient in most Espresso drinks by volume. Because of this, milk should be handled as carefully as Espresso is extracted.

Like choosing a coffee roaster, choosing a milk supplier should start from quality and blind testing. Cold milk and whipped milk bubbles should be sampled and tasted directly, and then mixed with Espresso.

Baristas should understand that the quality of milk provided by suppliers fluctuates with climate change and the diet composition of dairy cows. For several years, I had to change suppliers according to the season, because one supplier's milk was better in winter, while others were better in summer.

The main points of getting rid of milk foam

The following is a basic requirement for any barista to get rid of foam.

Only pour out the amount of milk you need for the drink you are about to make.

Create dense small bubbles by inflating the milk; the surface should be smooth and there should be no visible bubbles.

Heat the milk to 150-160 ℉ (about 65.6-71.1 ℃).

Plan ahead, so that the foam and Espresso extraction are basically completed at the same time.

Supply the drink to the customer before the foam breaks down!

Foam decomposition:

The same cappuccino or latte tastes much better before the foam breaks down than after 1 to 2 minutes. Putting a cup of milk coffee in the foam to decompose before drinking is as sinful as putting Espresso into spoilage. The quality of the drink is not long-lasting, if not finished in time, then the quality will decline. However, we cannot guarantee that customers will finish the drink as soon as they get the freshly baked drink, so providing each drink to the customer in the ideal form has become a goal pursued by baristas.

The following three steps can make milk-based drinks full of milk and long-lasting texture.

1. Steam gets rid of. The milk must be dense and bubbly after it has been whipped. The appearance of visible bubbles, overheating and overstretching will affect the texture of the drink.

two。 Pour. Pouring with an appropriate flow rate, or using the "spoon method", can help to delay decomposition.

3. Supply. After the beverage is made, it should be provided to the customer as soon as possible.

How to get rid of foam:

Use the smallest volume of milk tank that can fully accommodate the amount of milk required for the drink to be made. it is best to allow the tank to be about 30% to 50% full before it is disposed of.

1. Break the steam stick onto a wet dishcloth or dripping pan and turn on the steam to remove condensate from the steam stick.

two。 Insert the steam sprinkler just below the surface of the milk, near the center. The angle of the steam rod is about 10 °to 30 °.

3. According to the degree to which the milk needs to be whipped, the pressure of the steam stick is fully opened, or close to full boil. Less pressure is needed to dispense with a very small amount of milk (such as making Maggiados).

4. It begins to swell (i.e. foaming) and ends before the milk reaches 100 ℉ (about 37.8 ℃). Once the temperature of the milk exceeds 100 ℉, it becomes very difficult to produce high-quality foam.

5. In the process of expansion, the steam sprinkler is kept just below the surface of the milk and carefully inflates the milk so as not to form any obvious bubbles. There is a slight sipping sound when you pump air.

6. When the expected expansion is reached, lift the milk tank and let the steam stick sink into the depths of the milk. Adjust the angle of the steam stick to keep the milk spinning until the desired temperature is reached.

7. Turn off the steam stick, remove the milk tank, wipe the steam stick with a wet dishcloth, wrap the steam sprinkler and deflate.

Please note: when using certain shapes of steam sprinklers or machines with high pressure, pumping air under the surface of the milk will quickly cause the milk to become too foamy. At this time, the barista should put the steam sprinkler deeper, the pressure does not have to be fully turned on, or lower the setting value of the constant pressure.

Milk forms in different drinks:

In order to better discuss the contents of this section, the author will mention some drink names. All drinks mentioned here use classic Italian 180-ml and 240-ml wide-mouth ceramic cups as containers and 30-ml to 45-ml Espresso as the base.

Cappuccino (Cappuccino): use well-whipped milk. After the drink is fully layered, the foam should be about 1.3 cm thick with a spoon (this is only an estimate, which will be affected by the diameter of the cup mouth).

↑ cappuccino foam is required to be thick and soft, and you should not see an obvious unbeaten milk layer after pushing it away.

Latte (Cafe Latte): use moderately whisked milk. After delamination, the thickness of the foam should be about 0.6 cm.

2 minutes after the ↑ latte is made, the milk and coffee will be completely layered.

White coffee (FlatWhite): use minimum whipped milk. Only a thin layer of foam floats on top.

Adjustment of milk foam

No barista can make the perfect foam for every drink. If there is not enough milk, there is no chance to remedy it, so we can only send a new one right away. However, if the milk is sent too much, it can be adjusted to achieve the desired state.

To determine whether the milk is properly disposed of, put the vat on the bar and circle the milk slightly in place to rotate the milk. The rotation speed of the milk tank should be controlled properly, both fast enough to throw milk into the inner wall of the milk tank, and slow enough to avoid forming large bubbles. The more milk is whipped, the thicker it becomes as it rotates.

When it is too out of date, the thick layer of blisters on the top of the milk can be removed by adjustment. First of all, use a large spoon to remove some foam from the surface of the milk. Be careful not to let the spoon sink completely when skimming, so as not to scoop out the lower layer of milk. The surface should be laid aside as evenly as possible. After the adjustment, shake the density of the milk by rotation, and repeat adjustment and rotation if necessary. Adjust and rotate repeatedly until the density of the milk reaches the desired level. The whole adjustment process should be completed in a few seconds.

Rotation also slows the decomposition of milk. The effective rotation speed is fast enough to keep the surface of the milk smooth, but not so fast that new foam is created or the milk is spilled.

The harmony of extraction and dispensing.

Within a few seconds after the end of the Espresso extraction, the milk should be sent so that the milk can be reconciled with Espresso. After the Espresso extraction is completed, it is better to merge with the milk as soon as possible, but it takes about 5 seconds to stabilize after the milk is finished, and the adjustment needs to be completed in this short interval.

If the Espresso is not extracted after the adjustment, shake the milk to delay decomposition. Shaking does not require the help of a stick or other tools, however, even if you shake the milk, its structure will still decompose over time, so the milk must be used within 30 seconds.

The injection of milk

The author will introduce two kinds of milk injection methods: injection molding method and spoon method. Both methods have their own advantages and disadvantages, and both are essential skills for baristas.

Injection molding method

Injection molding is the mainstream way at present. First put the milk into the milk jar with a mouth (that is, the flower jar), and then inject the foam into the Espresso. Pay attention to control the flow rate of milk injection, not too fast to destroy the integrity of Crema, nor too slow to make the milk foam decompose in the flower jar. The flower jar is widely used because it allows milk to flow out vertically, making it easier to create flowers.

How to draw flowers

If you want to pull flowers, you must use fresh Espresso with a certain amount of fat, and properly mixed milk. Milk should look glossy and have no obvious bubbles.

The most common mistakes for beginners are to inject milk too slowly and to hold the tank too far from the liquid level. Too slow injection will cause the foam to break down in the tank, causing underfoamed milk to be injected into the drink, leaving enough foamed milk in the jar. This will make it difficult to pull flowers and end up with a cup of underfoamed drink. Holding the tank too far from the liquid surface will cause the milk to sink directly under the Crema rather than float on top of the Crema to form a pattern.

Tips: pulling up the vat during injection will prevent the milk from floating on the Crema, because gravity makes the milk flow faster. Lifting the vat up is like a platform dive: the milk will dive directly to the bottom of the cup, with little impact on Crema. Just as divers don't make big ripples when they pierce the surface of the water, and they also dive deep. On the other hand, keeping the spout of the tub close to the surface is like diving on the edge of the pool: milk pounces on the liquid surface of the drink, just as a diver jumps to the surface.

Spoon method:

The spoon method was first common in New Zealand, but the author has seen it applied all over the world. The benefits of the spoon method include delaying the decomposition of milk bubbles and maintaining the structure of the milk during injection. The disadvantage is that it takes more time than injection molding, requires both hands, and is more difficult to master.

When using the spoon method, it is best to choose a round-mouth bell-shaped milk jar whose edges are bent outward. When injected, the wide mouth of the bell-shaped milk jar is easier to observe the structure of the milk, and the spoon is easier to enter the milk tank to operate.

Before operating the spoon method, dispose of the milk and adjust it (if necessary). Then use the spoon as a valve to control the speed and density of milk injection. The details are slightly different when making different drinks, but they are basically the same.

1. At the beginning of the injection, cover it tightly with a spoon to allow only the densest and least beaten foam to flow out. Some baristas also use spoons to push away coarse milk bubbles before starting to inject them.

two。 The central part of Espresso was injected to stabilize the flow velocity and avoid destroying Crema.

3. Slowly loosen the spoon during the injection process to let the thicker milk flow out.

4. The surface of the finished product should be as smooth as a mirror and be able to make patterns on it.

When using a bell-shaped milk tank, the feeling of sending, adjusting and injecting is different each time. As a result, even experienced baristas need to be trained patiently, from adapting to mastering the use of bell-shaped jars and spoons.

The skill of using a spoon

Cappuccino. Use sticky milk foam that is fully whipped. When you gently rotate the milk tank, the foam will seem to "stick" to the inner wall of the milk tank. Use a spoon to block the coarse bubbles on the surface of the milk, allowing only the densest and least beaten foam to be injected into Espresso. When the cup 1x3 is full, gradually loosen the spoon to allow more foam to be poured into the drink. When the cup is full, remove the spoon completely from the milk. In the final stage, use a spoon to push some of the remaining fully whipped foam into the drink. The final product will form a bulging bag on the surface, with a dark Espresso around the edge of the cup and smooth white foam in the middle.

Cafe Latte. Use moderately whipped foam. The foam is significantly thicker than pre-disposed milk, but produces little reaction when rotating the tank (that is, it does not stick to the inner wall of the tank). Cover the rough bubbles on the surface with a spoon and begin to inject. During the injection process, slowly loosen the spoon to allow more foam to be injected into the drink, while raising the vat a few centimeters. In the end, lower the milk tank, and at the end of the injection, the spoon is removed completely or has only a little contact with the surface of the foam. After practice, you can also draw flowers.

White coffee. Use a minimum amount of milk foam. This kind of milk foam is only slightly thicker than the milk before it is sent off. Use a spoon to block all the foam and inject it into the beverage center at a steady flow rate. Be careful not to damage the Crema. In the final stage, take away the spoon and finish the drink, and the final product has only a thin layer of milk foam on the surface. The surface of orthodox white coffee is dark, with only a small white dot in the middle, but some baristas make patterns on white coffee.

Anecdote: who stirred my latte

A few years ago, I went to a cafe in Wellington, New Zealand and ordered a small latte. After the first sip, I felt that the flavor was more refined and mellow than any latte I had ever had before, and the taste lasted until the last sip. Usually, because most of the Crema floats on top, the latte will taste a little strong and irritating when you drink it, and it will become soft and light at the end of the drink. But I don't know what happened to that latte. I think I should order another one anyway. This time, I kept an eye on how barista Dave works. He first made an Espresso into the cup and used a flower jar to dispose of the foam. Then use a spoon to limit the flow, inject about 1 ounce (about 30 ml) of fine milk foam (rarely beat), then gently stir the mixture of Espresso and fine milk foam with a spoon. Finally, he turned the vat a few times and used the injection molding method to finish the drink. The design on the top of this latte is very beautiful, and it tastes as good as the previous one.

After talking to Dave for a long time, I realized that he stirred some fine milk foam with Espresso every time because he thought it would help the coffee flavor to be more evenly distributed in the drink.

↑ limits the flow rate, injecting about 1 ounce (about 30ml) of whipped milk foam into the Espresso, then stirring gently.

Why use the spoon method?

The author found that the drink made by spoon method is more stable for longer. I don't know why, maybe it's because at the beginning, only the tiniest foam is fused with Espresso, and then gradually increase the degree of milk foaming, so that the newly injected foam can be better distributed and maintained. According to the author's experience, if you quickly inject too many coarse milk bubbles, it will make the drink unable to merge with the milk bubbles added later, and eventually cause the milk bubbles to float on the top. For example: first inject the fullest milk foam, and then gradually limit the flow to inject finer milk foam. The thicker foam injected at the beginning does not blend well with Espresso, and it will be the same for the whole drink.

Foam sharing: using injection molding to make multiple drinks

When baristas use a large milk tank to continuously make several drinks by injection molding, the fullest foam will enter the first drink, and the foam in the next drink will become more and more inadequate. If you want to provide the right foam for every drink, baristas need to use "foam sharing".

To share bubbles, baristas need to create a sufficient amount of foam for all drinks. It takes practice to accurately estimate the extent to which milk bubbles will be sent when making multiple drinks. When the barista is not sure how much to spend, the barista can beat the foam a little more than expected, because even if excess foam is produced, it can be removed during adjustment.

After getting rid of the foam in the big milk tank, you need to take another milk tank out and exchange the milk foam back and forth between the two milk tanks several times. During the exchange, the thickest foam on the top is always poured out first, which means that the foam in the receiving tank will be thicker at first and thinner in the tank poured out at the same time. When the foam in the first jar reaches the consistency needed to make the next drink, you can end the exchange.

The following example illustrates the process of continuously making a 7-oz (210ml) cappuccino and a 7-oz (210ml) latte.

1. Fill with milk and fill a 20-oz (600 ml) conical pattern cylinder to 2 inches (0.6-1.3 cm) away from the cylinder mouth.

two。 Start the bean grinder.

3. When grinding beans, empty the handle and wipe it clean.

4. Put water on the first head, install the handle when finished, and put water on the second head at the same time.

5. Buckle the prepared handle and boil the head. Start the bean grinder. Remove the second handle and complete the preparatory work.

6. The two boiled heads begin to extract at the same time.

7. Dispose of the milk, and when it is finished, the milk is about 1.5 inches (about 3.8 cm) from the edge of the jar.

8. Pour about 1 beat 3 milk foam into another empty 20-oz milk jar.

9. Turn the foam in the first vat to see if its consistency meets the needs of cappuccino. If it does not match, it is necessary to exchange foam back and forth between the two vats until they meet the needs.

10. Use the first vat to make a cappuccino. Remember: priority is given to making drinks that use thicker milk bubbles.

11. Give me a cappuccino.

twelve。 Pour all the remaining milk into the second vat. Observe whether the viscosity of the mixed milk meets the needs of the latte. If the milk foam is too thick, it can be adjusted; if the milk bubble is too fine, you need to send a new jar of milk foam.

13. Make a latte and give it to you.

Use the spoon system to make multiple drinks:

When using the spoon method, you don't have to share the foam. Instead, you have to deal with the thickness of the foam before making each cup of drink. Baristas only need to use a spoon to control the thickness of the foam as if it were the flow rate.

The following example shows how to use only one jar of milk and use the spoon method to make two cups of 7-oz (210ml) drinks as above, first prepare the Espresso and dispose of the milk in a 25-oz (750ml) bell-shaped milk jar.

1. To make a cappuccino, at first use a spoon to block all the foam, then slowly loosen the spoon and gradually let the thicker foam flow out of the vat. There is a significant increase in the number of milk bubbles in the vat compared to when making a single cappuccino, so the spoon barrier needs to be increased, and the coffee needs to be used to this when injected.

two。 Give me a cappuccino.

3. Turn the milk tank to see if the consistency of the remaining foam meets the needs of making lattes. If the foam is too thick, you can adjust it, or use a spoon to limit the foam during injection.

4. Make a latte and give it to you.

When making multiple drinks from only one vat, you can also use a spoon to stop the coarse bubbles, fill each cup with 1 cup and 3 fulls, and then fill the cups with fine bubbles. This is a very useful technique when you need to make more than two drinks at the same time.

Use a milk jar to make 4 cups of drinks

I once saw a barista make up to four cups of drinks from a milk tank through foam sharing (as my good friend Jon Lewis did in the 2006 American barista contest final). With the spoon method, it is easier to inject some coarse milk bubbles into 4 cups of drinks, and then inject fine milk bubbles respectively to complete the product.

When using the injection molding method, the foam sharing technology must be used, and the milk needs to be exchanged back and forth between the two vats before the first three drinks are injected. If the barista plans properly, the consistency of the remaining milk after three drinks will be just right for the fourth drink.

(chapter 4 ends)