Our Fruit Caviar

What is fruit caviar, you may ask? As you may have guessed from the name, fruit caviar isn't quite like the staggeringly expensive Beluga caviar nor the $2.85 jar of lumpfish that you can get down at the supermarket that even the cat won't touch. It doesn't even look like caviar. True, it's made up of small, round balls, but instead of being black or gray or salmon colored, they're pink or bright green or strawberry red or any of a range of other hues. And as to the smell, one whiff confirms that these never came from anywhere near a fish. Put some in your mouth and the delicate membranes pop; releasing not a salty, fishy flavor, but the taste of grapefruit or strawberries or mangoes.

It's pretty obvious at this point that making fruit caviar hasn't anything to do with sturgeons and the like, so where does it come from? The answer lies in chemistry (molecular gastronomy) and the key is a substance known as sodium alginate, which is a commercial thickener derived from seaweed and used in everything from ice cream to stomach tablets. When less than one half of one percent by weight of sodium alginate is added to a liquid, such as tomato juice or puréed blueberries, and then the mixture is added drop by drop to a bowl of water containing calcium chloride, a reaction occurs and each drop forms a tight membrane that looks and feels like that of caviar. It even pops in your mouth like caviar! What you use as a base for the liquid doesn't matter. It can be anything from borscht to Cointreau. So long as it's edible, the pH value isn't too extreme, and you remember to strain the juice beforehand, then you can pretty much use whatever you like.

Ready to try some? Then follow the recipe below:

Ingredients:
~ 1 cup paprika oleoresin (extract) for color

~ 1 teaspoon (2.0 g) sodium alginate (Note: Different brands of sodium alginate have different thickening properties. Start with ½ teaspoon of the sodium alginate and add more if needed.)

~ 1 cup water

~ 1 teaspoon (2.5 g) calcium chloride

Preparation:
~ In a small bowl, add sodium alginate to extract, gradually sprinkling it into the extract and whisking the mixture. This can be done by hand mixing or by use of an immersion blender. If the sodium alginate does not dissolve in room temperature extract, some gentle heating of the mixture may be required.

~ The sodium alginate-extract mixture will be thickened, but it should not be a gel. If too thick, add additional extract.

~ Combine water and calcium chloride in a bowl, stirring to dissolve.

~ Pour the extract mixture into a plastic squeeze bottle or large syringe and drip it into the water until the bottom of the bowl is covered in a solid layer of spheres. Let sit one minute.

~ Use a strainer to scoop the spheres out of the liquid or place a strainer over a second bowl, then pour the contents of the first bowl through the strainer.

~ Rinse the pearls in the strainer with fresh water and transfer to a kitchen towel to dry.

~ Repeat until you run out of extract.

~ Serve within an hour, because it will gel all the way through with time. Not bad, but not as exciting as having the spheres pop to let the interior liquid out.