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Chapter 1: Preface

Bubble Tea, The Pride of Taiwan

First, let's start with the name. "Bubble Tea" (珍珠奶茶 - Zhēnzhū Nǎichá) reflects the three important components of this drink: "Pearls" (珍珠) – actually referring to tapioca starch balls processed in food factories; "Milk" (奶) – usually creamer or fresh milk, creating different thicknesses depending on the fat content; and "Tea" (茶) – mostly black tea, green tea, or oolong tea, offering different flavors based on fermentation level and processing methods. Additionally, another extremely important element is sugar.

Benefits This Guide Offers Readers

This guide primarily provides information for anyone interested in bubble tea. Based on the author's past experiences, it explains the processes of production, preparation, and mixing from a scientific perspective, enabling readers to accurately learn the correct methods and break through common misconceptions, understanding this subject from a completely new angle. Furthermore, this book will also incorporate information about raw material suppliers and various equipment introductions, allowing you to easily obtain raw material information. Unlike typical recipes, through the content of this book, we will learn to stably control ingredients and flavors, and increase the potential for innovation.

『What should go here, a Slogan?』

History of Bubble Tea

The origin of bubble tea can be traced back to Taiwan in the 1980s, when beverage shops began combining milk tea and tapioca balls (粉圓 - fěnyuán) to enhance the drink's texture and visual appeal, creating this unique beverage. Within just a few years, bubble tea became immensely popular in Taiwan and gradually spread worldwide. Whether in other parts of Asia, or in Europe, America, and Australia, its presence can be seen everywhere.

However, the charm of bubble tea far exceeds its nature as just a sweet drink. Bubble tea is not only a beverage; it is more of a cultural phenomenon, symbolizing Taiwan's innovative spirit and food culture. Its emergence broke the norms of traditional tea beverages, showing people the diverse innovative possibilities for tea drinks. Bubble tea has become a representative cultural symbol of Taiwan, gaining recognition globally and deeply loved by enthusiasts of all ages.

In this text, we will explore various aspects of bubble tea, from its history, production process, and ingredients, to various flavor variations, and how it has influenced and changed our food culture. Let us unveil the mystery of this sweet treasure together and delve deep into the world of bubble tea.

The content of this text is based on various reference materials and shared experiences. Scan the QR code to watch video explanations.

About The Author

Chapter 2: Pearl Ingredients

Firstly, the main ingredient of pearls is tapioca starch (樹薯澱粉), one among many types of starch, slightly different from sweet potato starch (地瓜粉) or potato starch (太白粉).

Below is a discussion of the differences in product Hardness, Springiness, Gumminess, and Chewiness after heating for different starches (Reference: [Reference citation missing in original]):

Formula	Hardness (g)	Springiness	Gumminess (g)	Chewiness (g)
Tapioca starch 100%	122.6±4.0c	1.00±0.02a	94.5±1.9c	94.3±1.8c
Sweet potato starch 100%	174.8±12.3b	0.97±0.03a	132.0±11.7b	127.9±13.3b
Potato starch 100%	236.4±12.9a	0.97±0.03a	162.0±6.2a	157.8±7.3a
Values are mean±SD, n=5 Different letters(a-c) in the same column indicate significant difference (p<0.05)

Samples made with potato starch had the highest hardness, valued at 236.4g, followed by sweet potato starch (174.8g), with tapioca starch being the lowest (122.6g). There was no significant difference in springiness among the starches (p>0.05). Gumminess and chewiness tests also showed potato starch was the highest, followed by sweet potato starch, and the lowest was tapioca starch.

Additionally, all starches still possess common starch properties, such as: starch can break down (disperse) in cold water, thickens upon heating, hardens when cold, softens when hot, etc. These physical characteristics are closely related to the production process, and it is essential to memorize these properties to control stability.

Chapter 3: Cooking Pearls

What is the Goal (Purpose) of Cooking Pearls?

This is a difficult question, and many people will likely provide varied answers. The same question can be applied to ramen: If the question were changed to "What is the purpose of cooking noodles?", I believe more people could provide a correct and complete explanation.

There are many types of nutrients: protein, fat, carbohydrates, vitamins, minerals, water, etc. In the process of cooking, we transform food into the state we desire. For example, searing a steak not only enhances flavor but also uses high temperature to kill bacteria and parasites. Simultaneously, the temperature causes protein denaturation (like frying an egg), resulting in different textures and colors, making it easier for the human body to absorb. Protein grading and changes at various temperatures have corresponding experiments and literature explanations, which will not be elaborated here.

Returning to pearls, pearls are a type of starch, just like noodles or rice. Therefore, we can understand the purpose of cooking pearls from our daily experiences of cooking rice and noodles. When cooking rice, the grains start absorbing water, their volume expands, and density increases. Increased density causes them to sink (sinking followed by heating leads to scorching, which also applies to pearls). The more water absorbed, the softer the rice becomes. If too much water is absorbed, the rice turns into congee. So, when cooking starchy foods, it's essentially about cooking with water and allowing the starch to absorb sufficient moisture. The amount of water changes its texture, hardness, and elasticity. Similarly, preferring harder noodles means the noodles contain less water, implying less contact time with water. This indicates that water is the primary factor influencing texture when cooking pearls.

The Process of Cooking Pearls

Raw Material Selection:

References for many long-established pearl factories in Taiwan:

• Andes Boba https://andesboba.com.tw/
• Ting Jean Foods https://ting-jeanfoods.com/

Raw Material Selection:

Mainly using pearls from pearl processing factories; these are for commercial use, not the type made at home. There is a huge difference between the two, which will be detailed in later chapters.

If buying small quantities, you can find vacuum-packed brown pearls, typically in 5kg bags, on major Taiwanese shopping websites or Amazon. When purchasing, check if the vacuum seal is intact, and also check the color for any signs of turning white or moldy. Additionally, if there's a desiccant pack, pay attention to whether the pearls near it have turned white (the desiccant absorbs moisture towards itself, so pearls around it are more likely to get damp). If damp or moldy, the pearls will have changes in color and taste, not to mention hygiene and safety issues.

Size Specifications:

1.0mm, 1.2mm, 2.0, 2.3, 2.5mm... etc., different sizes. Pearls of different sizes will have different cooking times. Under the condition of maintaining the same texture (softness/hardness), larger pearls require more time. In the following introduction, we will use 2.5mm pearls for explanation.

Tool Usage

Part 1: Heating Tools (Choose one):

• a. Induction cooker
• b. Gas stove
• c. Pressure cooker
• d. Electric cooker - Author's favorite - a 30-liter electric cooker, wider > deeper is sufficient
• e. Semi-automatic pearl cooker

Part 2:

• a. Pot - Minimum capacity should hold over 10 liters of water. A deep and wide pot is preferable. If limited, at least ensure it's deep.
• b. Spatula, Wooden spoon: Needs some length to avoid burns.
• c. Coarse strainer:
• d. Fine strainer:
• e. Measuring cup: With markings, choose a larger one around 4L or more. One 5kg bag of pearls (approx. 4 liters) can make about 80 servings.

Part 3:

• a. Brix meter (Refractometer) - Measures liquid concentration, a very important tool for standardization.
• b. Second-grade granulated sugar (二砂糖) - Sugar between brown sugar and white sugar. Pure brown sugar has a heavier flavor; although higher in molasses and nutritional value, its stronger taste can clash with some drinks. White sugar lacks sugarcane aroma but can be used for special flavored pearls, like strawberry or mango. Therefore, second-grade granulated sugar is more neutral and pairs well with most drinks.
• c. Clean water - Low TDS and filtered water, especially important that any taste is completely removed.
• d. Heat-resistant gloves: Protect your lovely hands from burns.

Hands-on Start - Tool: Induction Cooker:

Preparation

First Step:

Cut an opening in the pearl bag, but try not to make it too shallow, as subsequent storage still requires sealing as much as possible. Next, use a large *dry* strainer to sift out the pearl debris. Since pearls are made of tapioca starch + liquid (like snowballs), collisions during transport or handling can create debris that affects appearance, texture, and even cooking quality. After sifting, pour the pearls into a *dry* measuring cup to measure their volume.

Second Step: Boil Water

The minimum water requirement suggested by the author is at least 6 liters, and the ratio of water to pearls can be 6:1 or even 10:1. More water means higher heat content, which slows down the cooling rate after turning off the heat, similar to the human body (water is crucial for temperature regulation due to its high specific heat). Fill the pot with water and heat it on high power until it reaches a rolling boil.

Similarly, when cooking pasta, Gordon Ramsay adds a large amount of salt to the water, changing its concentration. This slows down the speed at which water enters the pasta, making the cooked pasta less likely to be too soft while also adding a slight salty flavor.

When making pork rib soup, salt is always added last. If salt is added first, the water's concentration becomes higher than the ribs', drawing water out of the ribs due to osmosis, resulting in dry and tough meat.

Adding salt when pickling kimchi also draws out water, another application of osmosis.

Some high-end restaurants use a lot of sugar to extract flavors from fruits, creating a flavored syrup. I once saw a process in a Las Vegas restaurant making strawberry ice cream: chefs put frozen strawberries in a large container with a lot of white sugar, refrigerated it overnight, and then used the resulting sugar water to make ice cream.

So, Controlling Osmosis = Controlling the Direction of Water

Third Step:

With the water boiling vigorously and the heat on medium-high, there will be a lot of hot steam, so be careful. Stir the water in the pot to create a vortex. Pour the pearls in very slowly, preferably from the side. Pay attention to whether the water bubbles disappear; if they do, it means the temperature has dropped, and you should stop adding pearls and wait for the water temperature to recover before continuing.

Therefore, pouring slowly is a crucial step. If the water becomes too thick, you must change the water or use other methods to lower the concentration. Additionally, pouring too quickly can damage the surface of the pearls, affecting the texture.

The process of pouring slowly, combined with the manually created vortex, allows the surface of each pearl to cook instantly upon entering the water. The vortex also whisks the pearls away immediately, preventing them from clumping together when poured continuously, thus avoiding pearls sticking to each other.

After all the pearls have been added, cover the pot and wait for one to three minutes (depending on the heat intensity; higher heat means shorter time) until the water returns to a boil. Then, start timing for 30 minutes (this is a tentative time, adjust based on the process, observations, and tools).

Cooking Process - 30 to 50 minutes

Fourth Step:

Cover the pot about 90% full, do not seal it completely. This step is also quite important, serving two purposes:

1. Because the pearls have low density at this point and float on the water, covering the pot traps steam to humidify and heat the floating pearls.
2. It increases the pressure inside the pot. Increased pressure makes the pearls expand larger, thus widening the pores, allowing water to enter the pearls more quickly.

As shown in the right picture, you can use a long spoon to prop the lid, leaving a small gap.

Furthermore, pearls being heated by steam will appear lighter in color.

, If not heated or touched by steam, the pearls will appear black. You can perform a small experiment: the moment you lift the lid, the pearls will instantly change from a light color to a dark color, indicating that opening the lid let the steam escape, and the dark color means the pearls were not being cooked. The first picture shows the pearls just scooped out, the second picture shows the pearls turning dark. Therefore, we can easily determine if the pearls are being cooked by observing the color difference.

Important Notes:

• ! Once the lid is on, try not to disturb it. Every time the lid is opened, temperature, humidity, and pressure need to build up again.
• ! Up to this point in the process, there is no need to stir.
• ! Set the timer for 30 minutes, then observe.

Finishing the Cooking Process - 1 to 10 minutes

This step requires multiple trials to establish the in-store recipe. During food cooking, many factors influence quality. Of course, temperature, time, and ratios, commonly heard factors, definitely have an impact. But there are also many other factors such as: heat power (火力), pot material, local ambient temperature, water quality, pearl moisture content (powder properties also differ; tapioca is a plant, its moisture content varies with season and weather; although factories control it, storage, packaging, etc., all have an impact), different brands of pearls... and many other factors. Therefore, this step requires observing the state of water absorption by the pearls.

As shown in the picture, throughout the cooking process, the pearls continuously absorb water, and their density gradually increases, just like the Titanic, they will eventually sink. If the pearls sink while the heat is still on, the entire pot will scorch and burn. Therefore, this step requires observing when the pearls start to sink in your specific shop (environment). Note down the time when sinking is imminent, conduct multiple experiments, and then establish a Standard Operating Procedure (SOP).

At this point, you can scoop out some pearls and use a transparent container to observe if they are about to sink. Reaching this state is sufficient. The picture on the left indicates that only 10% or less being submerged is enough.

The right picture shows the condition of cooked white pearls. The state on the right is that the pearls are sinking, but in the pot, they might not appear fully sunk. This condition has also met the target.

!Note: Even if they have started sinking, because it's just the beginning, the pearls are not yet heavy enough to stick to the bottom. Therefore, there is some buffer in this operation, and it's unlikely to scorch, but it's still recommended to observe until the first condition (just starting to sink) is met.

At this point, the pearls have absorbed enough water and are starting to sink. Therefore, continuing to heat will cause burning, whether using an induction cooker or a gas stove. So, the heat needs to be turned off at this time, but simultaneously, we want the temperature of the water in the pot to remain high, and ensure that all the pearls are immersed in the water.

Now, open the lid, stir for about 10 to 15 seconds, ensuring nothing is sticking to the bottom. Then, close the lid, possibly placing a weight on top, and wait for 10-30 seconds (depending on the density of the pearls; if they sink too quickly, don't apply heat for too long - *implies using residual heat*).

After sealing and covering (potentially with weight), immediately turn off the heat. No further heating is possible at this time because the pearls are now close to sinking, and continued heating risks scorching. A burnt taste will permeate the water, so this must be carefully avoided.

At this stage, the pearls will slowly absorb water. The center part is harder (denser) and requires a longer time to absorb water. This time is related to the factory manufacturing process (granulation - 造粒).

Osmosis

The change in the direction of water movement due to different concentrations is a physical phenomenon and a method constantly used during the pearl cooking process. Below is a simple explanation of the osmosis phenomenon:

• When pasta is placed in hot water, the starch particles in the noodles absorb water and begin to swell. At this time, water molecules move from the external environment (hot water in the pot) through the starch network on the noodle surface towards the inside. This is because the concentration of starch particles inside the noodles is higher than the external water, so osmotic pressure drives water molecules inward. This way, the noodles can absorb water and soften. Replacing noodles with pearls follows the same principle.
• Placing green papaya together with sugar + salt causes the moisture within the food to move outwards, thereby achieving dehydration and preservation effects. This is logically similar to the final step of marinating pearls (醃珍珠).

Soaking Process - 40 to 80 minutes

The following procedure is very simple. If your pot is large enough and contains enough water, it's just a matter of waiting + checking.

Key Points for This Step:

1. Keep the pot covered the entire time, except when checking.
2. Maintain a high temperature, at least 80°C or higher. If the temperature is insufficient, the entire water absorption process will be very slow.
3. Try to place the pot on a well-insulated surface, such as a wooden mat. Placing it on a metal platform is not recommended.
4. The goal of the soaking process is to allow the pearls to continuously absorb water in high-temperature water. Naturally, the thicker (more viscous) the water, the slower the process. If the water is too clear, the surface layer is more likely to become soft and mushy.

During this step, you can check once every 30 minutes. It is recommended not to check too frequently, as the pearls are slowly absorbing water, and opening the lid or checking will lower the pot's internal temperature and slightly reduce the pressure. Just check at the designated times.

Observation Focus:

Observe the color of the pearls. This observation is somewhat difficult, as most black pearls quickly turn black upon cooling. You will need to use a flashlight (a phone's flashlight works) to observe. The main goal is to observe the hydration status throughout the pearl. After absorbing water, the pearl will become transparent with a black hue and translucent. The part that hasn't absorbed water will be light brown but opaque. So, scoop out the pearls and use a flashlight to assess the progress.

The image on the right shows that starch becomes translucent after absorbing water. This picture uses white pearls as an example, clearly showing the difference in the pearls themselves based on varying degrees of water absorption.

Question: Why do pearls need to absorb water?

• Starch softens and becomes slightly elastic after absorbing water.
• If starch contains little water, it will harden upon cooling, like the pearls in the picture. Once placed in something cold like a smoothie, they instantly become hard, regardless of how soft they were initially.
• Facilitates flavoring. Pearls themselves have a very faint taste, especially after soaking in water for a long time; flavors, preservatives, etc., dissolve away with the water. Therefore, subsequent flavoring becomes the main source of taste. If the inside of the pearl has not absorbed enough water, flavors like honey or brown sugar cannot penetrate (water is the best solvent; without water, it's difficult to transmit sweetness to the pearl's center).

Therefore, to make brown sugar pearls (黑糖珍珠), it is even more crucial to increase the proportion of water absorbed by the pearls, so that the entire pearl tastes flavorful.

Next, during the soaking process, you need to observe the color of the pearls periodically. Because they become translucent when hydrated and remain opaque when not, you can proceed to the next step once they reach your desired level of hydration.

There are two images here. The upper part of the first image shows some parts with white centers (白心 - bái xīn). A white center indicates that it will harden when cold, similar to the texture of cold white rice (somewhat like taro balls - 芋圓, but less powdery). Simultaneously, it also means the white center part is less likely to absorb flavor.

The image below shows that almost all pearls have absorbed sufficient water. This is a very good state, but it may not necessarily match the preference of Taiwanese people, some of whom prefer firmer pearls. However, from an international perspective (non-Asian regions), people prefer chewy (Q) but dislike hard textures. In many international cuisines, it's less common to add such non-fruit, hard items to beverages. Therefore, popping boba (爆爆珠 - bào bào zhū) is actually very popular because it's like a fun juice ball. Furthermore, in some culinary and alcoholic dessert applications, products equivalent to popping boba are quite common. (Popping boba is a combination of sodium alginate and calcium lactate, which will be provided later).

Once the pearls reach this state, proceed to the next step.

Rinsing and Flavoring - 5 to 10 minutes

After completing the previous step, the pearls need to be rinsed. However, this is not necessary for pearls intended for Brown Sugar Milk Tea (黑糖撞奶 - hēitáng zhuàng nǎi, literally "brown sugar hit milk").

Purpose of Rinsing:

• a. To wash off some of the starchy water clinging to the pearl surface, which affects the ease of scooping (too sticky can be messy). After rinsing, the pearls become shiny, and the lower the water temperature, the shinier the pearls appear.

• b. Can separate some pearls that are stuck together, improving the issue of clogging when using a straw.
• c. To cool down the pearls, similar to the principle of rinsing noodles with cold water after cooking.

Equipment Preparation:

• a. A strainer with holes; being easy to clean is important.
• b. If the pot is too hot or heavy, be sure to use a measuring cup to scoop slowly.

Rinsing Method:

• Using warm or cold water is fine.
• When rinsing, just look for shininess and ensure there are no sticky starch clumps (which look like snot - 像鼻涕的東西).
• The water needs to be very clean; if it has an odor, it cannot be used. Therefore, installing a water filter is necessary.
• After rinsing, it is imperative to rinse again with potable/drinking water (生飲水 - shēng yǐn shuǐ). When doing this final rinse, use a large amount of water at once, suggested 4 liters or more, to ensure all pearls are washed. Injecting too little water at a time will not achieve a clean rinse effect and will waste a lot of water.
• Large quantities can be rinsed in batches.
• Brown sugar pearls do not need washing; they can be separated beforehand.
• Rinsing time doesn't need to be long; just ensure the stickiness is washed off. Rinsing more is unnecessary.

Flavoring:

Prerequisites for Flavoring:

• a. Pearls are full of water. Water acts as the solvent for flavor (sugar dissolves in water).
• b. High-concentration granular sugar (powder, not liquid).
• c. A basin or bowl.

• d. TDS meter (for stabilizing concentration).

Ratio: 1:4 (Visual estimate by volume)

Principle of Flavoring:

This is the reverse of the pearl cooking process. During cooking, we sent water *into* the pearls, making them full of water like a cucumber. Now, we add crystalline sugar.

The sugar creates a huge concentration difference, causing osmosis to occur. This is why we use powdered or crystalline sugar, as these forms can achieve over 99% sweetness concentration, making it the most efficient method. (Many shops use fructose or other liquid sugars for flavoring, ultimately resulting in a lot of sugar being poured down their sinks.)

• The pearls on the left are mostly water, with lower concentration (L). The right side represents crystalline sugar with higher concentration.
• Direction of water movement: Net movement from pearls to the outside > from outside to the pearls.
• Under osmosis, the sugar dissolves quickly and slowly distributes evenly within the pearls. It often takes 5-20 minutes for the flavor to reach the very center.
• Pearls will start to become less soft as water is drawn out. The texture will become increasingly firm and elastic (扎實 - zhāshi).

Precautions Before Secondary Flavoring:

1. Ensure there are no remaining sugar crystals; they must be completely dissolved.
2. You can use a TDS meter to test the concentration. A concentration between 50-55 (reference value) ensures the pearls won't excessively swell or become hard.
3. If the TDS reading is too low, more sugar needs to be added. If too high, add a small amount of hot water to reach the target value.
4. You can test the texture and taste. Placing the pearls in water filled with ice is an excellent way to test. If the pearls didn't absorb enough water during cooking, they will harden quickly (although if the test reveals they are too hard, there are few ways to remedy it; however, if they are too soft, you can still add more sugar to draw out more water from the pearls for fine-tuning).

Principle of Secondary Flavoring:

When the pearls and the sugar liquid reach equilibrium, the liquid flows evenly between the pearls and the sugar water. At this point, simply adding a small amount of flavorings like "honey" or "maple syrup", or other preferred seasonings, into the liquid will allow the entire pearl to be filled with flavor. Generally, for half a bag of pearls (2 liters), adding 100ml of honey for flavoring is sufficient. This is somewhat like seasoning cold-tossed cucumber salad: first use 3% salt to draw out the cucumber's internal water and reach equilibrium, then add small amounts of chili, garlic, etc.; these flavors will dissolve in the water and be carried to every corner (sometimes adding too much salt causes excessive water loss from the cucumber; in this case, no matter how you season it, because the cucumber has too little water, the flavor struggles to penetrate, resulting in a feeling of seasoned surface but raw inside).

So, at this stage, you can choose your favorite flavors to add to the pearls, because any flavor that can dissolve in water can diffuse into every pearl.

Pearl Storage:

There are many ways to store pearls. Some people prefer to keep them warm, while others like to store them in plastic containers. Regardless, there are a few things to pay attention to:

• a. Temperature should not be too cold. Because if the pearls were not cooked well (insufficient water absorption), they will quickly harden in a low-temperature environment, much like white rice. Therefore, keeping them warm is best, room temperature is acceptable, but low temperature is not advisable.
• b. Always cover the container to prevent foreign objects from falling into the pearls and affecting hygiene.

One Last Thing

Storage typically isn't completely airtight, meaning that water will inevitably evaporate over time. Consequently, the concentration of the liquid preserving the pearls will inevitably become higher. In drier regions, the concentration may need adjustment after about an hour, which means adding a little water and re-measuring the TDS to between 50-55. If you accidentally add too much water, you can stir, pour out the excess water, and add an appropriate amount of sugar.

This adjustment step needs to be repeated approximately every hour. This helps control the softness and hardness of the pearls and can extend their lifespan to 8 hours or even longer. However, food hygiene issues still need attention; it's recommended to keep them covered and use them within 6 hours.