Colorful Jelly Water Spheres

Colorful Jelly Water Spheres


Use molecular gastronomy spherification to create these colorful jelly spheres. They are fun to create, squish, and play with! Once you master this process, feel free to explore with different colors and sizes! The main ingredients necessary for this experiment are sodium alginate and calcium lactate. Both of these are relatively easy to find and and order online.

Ages:
10 - 14
Est. Time:
<1 hour

How we did it:

Materials List

  1. sodium alginate (3/4 tsp) - a brown seaweed extract
  2. calcium lactate (3/4 tsp)
  3. hand mixer
  4. fork
  5. large bowl (2)
  6. small cups/bowls
  7. slotted spoon
  8. food coloring
  9. water
  10. pipette - or syringe
  1. Fill your first bowl with 1 cup of water. Slowly add in the sodium alginate while using the hand mixer until the sodium alginate is completely dissolved. (This will require strong agitation as the sodium alginate prefers to clump rather than dissolve). If there are a lot of bubbles after you are done mixing, cover the bowl with plastic wrap and let sit in the refrigerator for 12 hours. *


    Tip:

    If the sodium alginate is not mixing well, lightly heat your liquid and then continue to mix on high speed. Additionally, distilled water will work better than tap water if your tap water is very hard (full of minerals).


    *It is important to remove air bubbles since trapped air will create weak spots in the gelled skin and prevent the droplets from sinking properly.

  2. Prepare the bath: In the second large  bowl, add the calcium lactate to 1 cup of water. Use a fork to mix well. The calcium lactate should dissolve easily.

  3. Once your sodium alginate mixture is bubble free, carefully separate the mixture into the smaller mixing cups. Use your food coloring to color each cup.

  4. Using the pipette, suck up some colored liquid and slowly squeeze droplets into the calcium lactate bath. You should be able to see the little spheres take shape.

  5. After you have squeezed in a couple of spheres, carefully stir the mixture with your hand. As you stir, the spheres will begin to harden and the gelled skin around the colored water will become thicker.

  6. After 15-45 seconds, remove the spheres with a slotted spoon. You now have a handful of colorful water jelly spheres!


    These spheres will continue to harden over time. While these are safe to eat, we only used them for play!



    You can also make larger water jellies by using a spoon to drop bigger portions into the calcium lactate bath. Be careful to not puncture them as you stir as they will be very delicate. Larger jellies will need to sit longer in the calcium lactate bath.

  7. What is going on? 


    You have just pulled off a technique called spherification, which occurs when long molecules of sodium alginate react with calcium. Calcium ions in the calcium lactate solution replace sodium ions in the sodium alginate, and because calcium can form multiple chemical bonds, the long alginate molecules all begin to stick together, forming a more rigid, gel-like structure. Chefs use this technique, as well as its cousin process (reverse spherification, in which liquids with calcium are added to a sodium alginate bath), to turn flavorful liquids into balls of "artificial caviar." This is one of the more simple examples of molecular gastronomy, and if you are interested, you can find recipes for more appetizing spherified liquids online.