Before you ask…yes, this is another molecular gastronomy recipe. The technique I used is called “reverse spherification”, and was based on Surprise Bubbles.
The fascinating thing is that this technique is so simple that these colored bubbles were mainly made by my niece and nephew, 14 and 11 years old…
They had so much fun making and then eating these popping bubbles filled with grape juice…more specifically white grape juice. Initially we started with the non-color ones (original color of the white grape juice). Since it was kind of hard to see and manipulate the translucent bubbles, we decided to color them by adding a few drops of food coloring into the alginate solution. Erica chose red and Nick blue…and off we went, each one with their bowls of colored alginate bath and water…I played with the non-color ones.
They first removed the frozen half sphere from the freezer and dropped in the alginate bath for 3 minutes. Then they scooped the bubbles from the alginate bath and placed them into a bowl of water to remove the excess alginate. After “collecting” lots of bubbles we just ate by “popping” one at the time in our mouth…a very fun experience, especially because these bubbles were like 0.3oz size and you sure feel the bubble exploding in your mouth and the refreshing juice.
½ cup white grape juice or any juice of your preference
1 teaspoon sugar
½ teaspoon calcium lactate
400 ml of filtered water
2 g sodium alginate
Prepare the alginate bath by mixing the sodium alginate in water, until the sodium alginate is totally dissolved. You can use an immersion blender. Once the sodium alginate is dissolved, let the solution rest in the refrigerator for approximately 24 hours or until all the air bubbles disappear.
A few hours (or 24 hours) before the spherification, mix the grape juice with sugar and calcium until the calcium is dissolved. Carefully spoon in a silicon mold and freeze.
Drop the frozen juice in the alginate bath and let it sit for 3 minutes.
Scoop the bubbles using a slotted spoon and rinse them in a bowl of water.
Remove from the water and they are ready to be served.
Did you know that “spherification” is simply a gelling reaction between calcium and alginate which is a gum like substance removed from brown seaweed. So by adding calcium, we just replace what the manufacturers removed from the seaweed, therefore the gelling texture.