Crystal Boba: A Tapioca Pearls Alternative Using Agar Powder

Crystal boba is a chewy bubble tea topping, a lower-calorie alternative to boba or tapioca pearls. Its translucent white appearance and soft jelly texture make them as delicious and fun to eat as black tapioca pearls. 

Using our recipe, you can make roughly a batch of 1 cup of agar agar boba, which will be enough for 4 servings. We'll show you how to make these using a mould and without one via spherification. Spherification might sound difficult without special tools, but trust us, it's easy to do at home. It also makes a fun "science project" for the kids at heart.

If you want to make some fun coloured agar boba topping, we've also included our brown sugar crystal boba recipe alongside taro, purple sweet potato, matcha, blue pea and strawberry.

Jump to:

• What Is Crystal Boba?
• Crystal Boba vs Boba (Tapioca Pearls)
• Crystal Boba Ingredients
• Crystal boba recipe using a mould
• How to make crystal boba from scratch (No Mould)
• Cooking Tips
• Crystal Boba | Agar Agar White Pearls
• How To Store
• Brown sugar crystal boba
• Matcha flavoured agar agar boba
• Strawberry pink boba
• Blue Crystal Boba
• Taro Crystal Boba

What Is Crystal Boba?

Crystal boba is made from fruit juice, sugar and either agar agar powder or konjac powder. Fruit juice is added for flavour, as crystal pearls are relatively flavourless without it. To make basic crystal boba, you will only need water, sugar and a gelling agent (agar agar powder or konjac powder).

Agar agar powder is a gelatinous substance made from algae that helps solidify the pearl shape and gives you a firm jelly texture. Konjac powder from the starchy root vegetable can also help make the jelly-like ball shape and have a bouncier and chewier texture.

White pearls or agar agar boba are a milky white iridescent colour. However, if fruit juice, food colouring or other liquid substance is added, it can change colour.

Buy or make at home?

As the ingredients are plant-based, they are safe for vegans and vegetarians. However, if you are buying these, you should check the ingredients to see if manufacturers have added animal gelatin for costs and to maintain the ball shape for longer.

Most manufacturers will pack them in flavoured syrup, which means the flavours are limited, and you can't customise the sugar level.

You only need a few ingredients to make this, which are relatively cheap, and it doesn't take more than 10 minutes of active work (or 5 minutes if you're using a mould) to make a big batch. We think making crystal boba from scratch is cost-effective and healthier, which is more flavourful than store-bought.

Crystal Boba vs Boba (Tapioca Pearls)

Crystal boba is milky white and slightly translucent, while tapioca pearls are usually black and opaque due to food colouring. They are similar in size and relatively flavourless without added flavouring, like brown sugar. Tapioca pearls are chewy and denser to bite, while crystal boba is bouncier, softer and jelly-like.

In addition, white pearls retain their texture and any added flavour better when added to a drink. In contrast, tapioca pearls can firm up over time and begin to impart their flavour to the surrounding ingredients. Therefore, they are different in appearance, texture and taste.

Generally, tapioca pearls are higher in calories than white crystal pearls. However, this can vary depending on how much sweetener has been added.

Crystal Boba Ingredients

For the crystal boba ingredients, you will need agar agar powder, sugar and coconut water (optional).

Agar Agar Powder

Agar agar powder is the gelling agent for crystal white pearls. We use this instead of Konjac powder as it's easier to find and has more uses. For example, you can use it to make vegan coffee jelly, raindrop cake and matcha pudding.

LIVING JIN Agar Agar Powder for Crystal Boba (4 oz)
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Coconut Water (Optional)

We add coconut water to give our white crystal boba a slightly sweet, sour, nutty taste. You can also use Sprite or plain water if you want to use something other than coconut water. However, to maintain the white iridescent colour, try sticking with liquids that are clear in colour.

For coloured pearls, you can play around with different kinds of fruit juices or fresh fruit puree. Try making taro crystal boba, matcha-flavoured, strawberry-flavoured, blue and brown sugar crystal boba for some fun variations. Measurements for each one are listed in the sections below.

White Sugar

White sugar is used for added sweetness. If you prefer your crystal boba to be less sweet, you can use less of this or omit it entirely. 

You can also use brown sugar for our recipe and make brown sugar crystal boba. However, it will look slightly yellow to dark brown depending on the type of brown sugar and how much you use. If you use palm sugar like gula melaka, your pearls will have a richer toffee-like sweetness and a darker brown colour.

Using gelatin or jelly powder

Some recipes use animal gelatin or vegan-friendly jelly powder to make crystal boba. These alternatives are fine. From our recipe testing, crystal boba made using gelatin or jelly powder is slightly firmer than agar-based crystal boba.

The difference in texture is miniscule. So, please go ahead with whichever ingredient is most convenient for you. 

If you want to mix the ingredients, we recommend using a 1:1 agar-to-jelly powder ratio.

Crystal boba recipe using a mould

If you're using a mould, making a large batch is quicker. We recommend using a smaller circle-shaped mould to mimic the shape of the pearls.

1. Add coconut water to a pot and heat it over medium-high heat. Add sugar and agar powder once it becomes warm but not yet boiling. Stir continuously using a whisk to dissolve both the sugar and agar powder.
2. Bring the mixture to a boil while still stirring continuously. The mixture will bubble up vigorously when it reaches boiling point due to the agar powder. At this point, reduce the heat to a medium level and allow the mixture to simmer for another 5 minutes. Continue to stir to prevent clumps from forming.
3. Once the agar mixture has been simmered for 5 minutes, remove it from the stove. Then, pour the hot agar mixture into the mould. 
4. As a tip, pour it into the centre area of the mould. Then, using a flat scraper, spread the agar mixture across the mould. Let it sit for 10 minutes.
5. Pop them out of the mould, and they are ready.

How to make crystal boba from scratch (No Mould)

If you're making crystal boba from scratch without a mould, you will need water, ice, vegetable oil, a small spoon, and the ingredients above.

1. Fill up a bowl with cool water and add ice to it. Set it aside in the fridge to allow the water temperature to decrease further.
2. Add coconut water to a pot and heat it over medium-high heat. Add sugar and agar powder once it becomes warm but not yet boiling. Stir continuously using a whisk to dissolve both the sugar and agar powder.
3. Bring the mixture to a boil while still stirring continuously. The mixture will bubble up vigorously when it reaches boiling point due to the agar powder. At this point, reduce the heat to a medium level and allow the mixture to simmer for another 5 minutes. Continue to stir to prevent clumps from forming.
4. Remove the pot from the heat and let it cool to at least 50-60 degrees Celsius. You don't want this to be any cooler than this temperature, as it will begin to solidify otherwise. If you don't have a kitchen thermometer, let it cool for about 5 minutes. 
5. Remove the bowl from the fridge and carefully pour oil into the bowl, ensuring the entire surface is covered in oil. Ideally, you want at least a 0.5 cm layer of oil.
6. Using a ½ teaspoon measuring spoon, remove some of your cooled mixtures and gently drop this into the oil and water mix. If you're using a clear bowl, you should be able to see the ball-shaped form and the crystal boba drop to the bottom of the bowl. Repeat for the amount you want.
7. Strain the crystal boba and rinse it 2 to 3 times using clean water.

Cooking Tips

Here are some cooking tips that will be useful when making this at home.

Using a squeezy bottle

This method aims to fill up a squeezy bottle with the agar mixture and then squeeze out droplets into the bowl of oil-water mixture. Although it may sound more convenient than hand dripping with a spoon, we don't recommend using a squeezy bottle for a few reasons.

From our experience, the crystal boba turns out stringy, and you need to control the squeezy bottle well for the crystal boba to turn out spherical. Just like how it's difficult to control the squeeze of ketchup using a squeezy bottle, you will run into the same problem here.

Instead, use a spoon to scoop the agar mixture to form the crystal spheres. Based on our experiments, the ½ teaspoon measuring spoons worked best for us as they have a fully round bowl to increase the chances of forming spherical crystals. The 1 teaspoon measuring spoon works fine to form the agar boba, but the spheres are a tad too big for the boba straw.

Stir continuously

Agar at the bottom of the pot may cook faster and solidify as a clump. Therefore, continuously stirring the mixture will ensure even heating of the agar mixture. 

You may also see some of the agar clump up if you add the agar powder too close to when the liquid mixture is close to boiling point.

Temperature of the agar mixture

For spherification to happen, the agar has to cool down to a temperature that is below 40 to 45 degrees Celcius.

We do this because agar solidifies between 40 and 45 degrees Celcius (104 - 113 degrees Fahrenheit). When it's above that temperature, it remains in a semi-solid state and at near-boiling temperature, it will become liquid.

We use the cool water and ice to allow the agar's temperature to drop upon contact. However, if the agar's temperature is still above 45 degrees when it is spooned and dropped into the ice bowl, spherification will not happen.

Based on our experience, allowing the agar to cool down to about 50 - 60 degrees before you start spooning it into the ice bowl is best.

If the agar mixture starts to solidify in the pot, put it back on the stove and reheat it for a few minutes to revert it to a semi-solid state.

Amount and type of oil

The amount of oil we put in our recipe is merely a suggestion based on a regular bowl that we use. However, you may need more oil if you're using a wide bowl for the spherification step. On the contrary, if you're using a narrow bowl or glass, you may get away with using much less oil.

If you're using a see-through bowl, add enough oil to form a 0.5 cm layer at the top. Any less will reduce the chances of spherification.

We also recommend using a neutral-flavoured oil. When spherification occurs, the oil will form a thin coating layer around each crystal boba piece. Straining and rinsing the crystal boba would remove most of this oily layer, but you can get some residue. The oil residue will contribute to the final flavour of the crystal boba. So, avoiding intensely flavoured oils like extra virgin olive oil is best.

For a more robust flavour and fragrance

We highly recommend using fresh fruit when making crystal boba. The fruit's natural aroma, flavour and colour will impart to the crystal boba, resulting in a much nicer crystal boba. We love doing this.

How To Store

Like other jelly desserts, agar agar pearls can last up to 7 days refrigerated. However, we recommend you eat these as soon as possible before the flavour starts to fade.

Brown sugar crystal boba

Following the same method as our recipe, here are the ingredients you'll need to make 1 cup of brown sugar crystal boba:

• 3 tbsps brown sugar
• 250 water
• 5 g agar

You will need to add the brown sugar simultaneously with the agar powder. We use light brown sugar, which makes champagne-yellow crystal boba. You can use palm or dark brown sugar for a darker brown-coloured crystal boba.

Matcha flavoured agar agar boba

Using the same recipe, here are the ingredients you'll need to make 1 cup of matcha crystal boba: 

• ½ teaspoon matcha (culinary or ceremonial; either is fine)
• 250 g water
• 1 tablespoon white sugar
• 5 g agar

First, whisk the matcha powder with some water to form a smooth paste. Then, you can add it in alongside the agar. 

This will produce a dark green-coloured boba with a relatively strong matcha flavour. 

Add less matcha powder if you want it to be a lighter colour, but you will get a lighter taste. Otherwise, add a touch of plant-based milk for a brighter green colour.

Strawberry pink boba

Using the same method as our main recipe, here are the ingredients you'll need to make 1 cup of pink strawberry crystal boba:

• 75 g (½ cup) of strawberry
• 250 g water
• 1 tablespoon sugar
• 5 g agar

We blended the strawberries in a smoothie blender before adding them to the pot at the same time as the agar. You can add more strawberries for a stronger flavour, aroma and colour.

Blue Crystal Boba

Using the same recipe, here are the ingredients you'll need to make 1 cup of blue crystal boba:

• 2.5 g (¾ tsp) blue pea powder
• 250 g of water
• 15 g sugar
• 5 g agar powder

Blue pea powder has a very subtle floral, sweet taste. ¾ teaspoon of the powder will result in a dark blue crystal boba. We recommend adding less blue pea powder or a touch of plant milk for a lighter colour.

Taro Crystal Boba

Using the same method as our recipe, here are the ingredients you'll need to make 1 cup of Taro crystal boba:

• 2 tablespoon (25 g) Taro powder mix
• 250 g of water
• 5 g agar powder

Mix butterfly pea water with lemon juice or use food colouring for a stronger purple colour. 

However, for a more vivid purple colour, use purple sweet potato powder:

• Purple sweet potato crystal boba(makes 1 cup)
• 1 teaspoon purple sweet potato powder
• 250 g water
• 15 g sugar
• 5 g agar powder

Be careful with adding too much sweet potato powder. As the colour is quite potent, adding too much will result in a very dark indigo that is close to being just black.