An edible water bubble or bottle is water that has been solidified into a bubble-like shape. It is made from water, sodium alginate, and calcium lactate. If you prefer something more flavorful, you might enjoy a Japanese raindrop cake instead. The raindrop cake itself is flavorless, unless you sweeten it with vanilla sugar, or drizzle sweet syrup on top.


Edible Water Bubbles[1]

  • 1 gram sodium alginate
  • 5 grams food-grade calcium lactate
  • 5 cups ( 1.2 L) water, divided

Serves: varies

Japanese Raindrop Cake[2]

  • 3/4 cup (180 mL) water
  • 1/8 tsp + 1/16 tsp agar powder


  • 1/2 to 1 tablespoon (2.63 to 5.25 g) roasted soybean flour (kinako)
  • 1 to 2 tablespoons (15 to 30 mL) black sugar syrup (kuromitsu)

Serves: 2 to 6

Method 1
Method 1 of 2:

Making Edible Water Bubbles

  1. Use a kitchen or a digital scale to measure out 1 gram of sodium alginate. Place it into a bowl, then add 1 cup (240 mL) of water. Mix the 2 ingredients together using an immersion blender until the sodium alginate dissolves.
    • You can purchase sodium alginate online. It is a natural ingredient that comes from brown seaweed.
    • If you don't have an immersion blender, you could try a regular blender or a whisk.
    • Don't worry if the mixture develops air bubbles. These will go away as you prepare the other ingredients.
  2. Pour 4 cups (950 mL) of water into a large bowl, separate from the first bowl. Add 5 grams of calcium lactate. Stir the 2 ingredients together with a spoon until the calcium lactate dissolves.
    • Make sure that you are using food-grade calcium lactate. It's a type of salt used in cheese that can be bought online.
  3. Take a deep spoon, such as a sauce ladle, and scoop up some of the sodium alginate mixture. Hold the spoon over the surface of the calcium lactate mixture, then carefully tip its contents in. Do this a few more times until the bowl is filled.
    • Do not overcrowd the bowl with sodium alginate.
  4. Use a slender spoon to gently stir the contents in the large bowl. Keep stirring for 3 minutes. This will help activate the ingredients, and cause the sodium alginate to condense into "bubble" shapes.
  5. Fill a large bowl with plain water; the exact amount does not matter, as long as it is filled. Use a slotted spoon to remove the sodium alginate bubbles 1 by 1, and transfer them into the water. This will help stop the reaction.
  6. Set them down onto a plate or into a bowl. At this point, you can eat, drink, or slurp the bubbles up. You can also give them to young children to play with as a sensory activity!
    • Because these bubbles don't contain much, don't expect them to be very tasty!
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Method 2
Method 2 of 2:

Making Japanese Raindrop Cake

  1. Get out a set of measuring spoons. Use the 1/8 teaspoon to measure out 1 1/2 scoops of agar powder into a saucepan.
    • For best results, use Japanese-style "Cool Agar." Do not use agar flakes.
  2. Japanese raindrop cakes are supposed to be flavorless; you add the flavor with soybean flour and sugar syrup once you are ready to serve the cakes.[3] If you want a sweeter, less-traditional raindrop cake, add 1 pinch of vanilla sugar.
  3. Pour the water into the saucepan a little bit at a time. Stir the water with a spatula until the agar powder dissolves.
    • The traditional recipe calls for mineral water, but if you can't find that, spring or filtered water will do.[4]
  4. Set the saucepan on a stove. Turn the heat up to medium, and wait for the mixture to come to a boil. Cook the mixture for 1 minute, stirring occasionally, then take the saucepan off the stove.
    • The timing is important. If you undercook the mixture, the agar won't dissolve. If you overcook the mixture, it will condense too much.[5]
  5. You can use special molds made specifically for raindrop cakes, or you can use large, round silicone molds instead. If your mold is a 2-part mold that looks like a deep tray with wells in it, do the following:[6]
    • Fill the lower mold so that the wells overflow and the tray is half-filled.
    • Wait 2 minutes, then add a filling, such as an edible flower or strawberry.
    • Place the upper mold (with the holes in it) on top.
    • Press down on the upper mold until the excess gelatin flows out of the holes.
  6. The raindrop cakes will be set within 1 hour, but nothing will happen if you leave them there longer. In fact, it would be even better if you left them there overnight.
    • How many cakes you end up making depends on how many cavities were in your mold.
  7. These jiggly treats will melt and lose their shape after only 20 to 30 minutes, so plan ahead. Once you are ready to serve the cakes, turn the molds upside down onto serving plates, and let the cakes slide out. Place each cake onto a separate plate.
  8. Add 1/2 to 1 tablespoon (2.63 to 5.25 g) of roasted soybean flour next to each cake. Drizzle 1 to 2 tablespoons (15 to 30 mL) of black or brown sugar syrup over each cake. Alternatively, you can place the syrup next to each cake instead of drizzling it on top.
    • You can make your own black or brown sugar syrup. Follow a simple syrup recipe, but use brown sugar instead of white.
    • If you can't find soybean flour and black sugar syrup, or if you simply don't like them, drizzle some honey or agave nectar over the cakes instead.[7]
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Community Q&A

  • Question
    Where can I buy the ingredients?
    Community Answer
    Community Answer
    You can buy calcium lactate on Iherb. You can purchase sodium alginate on Amazon or Iherb.
  • Question
    Can I use calcium chloride instead of calcium lactate for making edible bubbles?
    Community Answer
    Community Answer
    No. Calcium chloride will turn into chlorine, and is thus toxic. (It's used for cleaning pools.)

Things You'll Need

Edible Water Bubbles

  • 2 to 3 bowls
  • Immersion blender or regular blender
  • Slotted spoon
  • Deep spoon (i.e. sauce ladle)

Japanese Raindrop Cake

  • Saucepan
  • Rubber spatula
  • Spherical mold

About This Article

wikiHow Staff
Co-authored by:
wikiHow Staff Writer
This article was co-authored by wikiHow Staff. Our trained team of editors and researchers validate articles for accuracy and comprehensiveness. wikiHow's Content Management Team carefully monitors the work from our editorial staff to ensure that each article is backed by trusted research and meets our high quality standards. This article has been viewed 139,506 times.
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Co-authors: 25
Updated: January 10, 2024
Views: 139,506
Article SummaryX

Edible water bubbles are made from water that has been solidified into a bubble shape with sodium alginate and food-grade calcium lactate. To make your own,, you’ll first need to mix 1 gram of sodium alginate with 1 cup of water and blend the mixture until the sodium alginate dissolves. In a separate bowl, combine 5 grams of calcium lactate with 4 cups of water. Then, spoon 2-3 spoonfuls of the sodium alginate water into the bowl of calcium lactate water. Stir the ingredients together for 3 minutes, which will activate the sodium alginate and cause it to condense. Once the bubbles have formed, scoop them out with a slotted spoon and place them in a bowl of plain water. You can then eat them or give them to children to play with. For tips on how to make a Japanese raindrop cake with edible bubbles, read on!

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