Select Page
Print Friendly, PDF & Email
Popping Boba

Popping boba is popular topping for frozen yogurt. It is also often served in fruity bubble tea. Traditional boba is tapioca based, but popping boba is made from juice. The little juice spheres have an outer gel layer that is created in a process called spherification.

hundreds or yellow colored popping boba displayed in a white bowl

Spherification is chemical reaction that occurs between calcium chloride (or calcium lactate) and sodium alginate. To perform this chemical reaction, you dissolve calcium chloride in water, then dissolve sodium alginate in juice. The juice solution is then dripped into the calcium solution. The calcium chloride causes the sodium alginate to gel, forming a membrane around the juice.

Molecular Gastronomy

Molecular gastronomy is a sub-discipline of food science. Molecular gastronomy focuses on the chemical reactions that occur while cooking. Spherification is a chemical reaction.


Trouble Shooting

Written Instructions
  1. Place one cup of juice into a blender. If you don’t have a blender, place the juice into a bowl and get ready to whisk AGGRESSIVELY. 
  2. Add the 1/4 teaspoon of sodium alginate to the juice and run the blender on high for 2 minutes. Alternately aggressively whisk for several minutes.
  3. Run your juice solution through a mesh strainer afterwards if you see obvious lumps
  4. Refrigerate a couple hours or overnight so the air bubbles pop.
  5. Skim any additional bubbles off the top the next day
  6. Create a salt bath in a bowl by pouring the one teaspoon of calcium chloride into two cups of water.
  7. Pour plain water into another bowl.
  8. Use your food syringe to suck up some of the juice solution.
  9. Carefully drip little bubbles/spheres of juice into the calcium chloride solution.
  10. Swish the bubbles around with a spoon, then rinse them in the bowl of plain water
  11. Drain the juice bubbles from the water and enjoy your popping boba !

A Math Moment

Direct spherification requires a .5% solution of sodium alginate. If one cup of juice needs about 1/4 tsp of sodium alginate, about how much does two cups of juice need?


About 1/2 teaspoon

Given these conversions, could you tell me how much sodium alginate, in teaspoons, would be needed in a gallon of juice to make a .5% solution?
1 tablespoon = 3 teaspoons
1 cup = 16 tablespoons
1 gallon = 16 cups


3.84 teaspoons for exactly .5%