The other day I had a little time to try out a spherification experiment. Aided with food grade sodium alginate and calcium chloride, and a packet of Yuzu juice, I tried to spherify some Yuzu juice...
Here is a large packet of Food grade Sodium Alginate. I bought this in the UK because I was a bit nervous about getting Sodium Alginate from China which was likely to happen if I tried to buy it in Singapore. Alginate is a naturally occurring substance that comes from brown algae and it is the substance that apparently forms the (slightly crunchy) skeletal component of their cell walls.
Yuzu juice with green food colouring added for visibility, in measuring spoon about to be introduced to Food grade Calcium Chloride Bath. I made the yuzu mixture according to a book I had which suggested about 6 tablespoons fluid + 1/4 teaspoon sodium alginate. I don't know what equates to in percentage but I think I erred on the side of putting more sodium alginate which I later realised was truly unnecessary as it jellifies very easily.
It touched the bottom and promptly flattened itself. On hindsight, using a deep bowl with round edges might have helped avoid this as well as taking care to drop it more gently and not from a height.
Slightly self-flattened yolk of yuzu juice.
Smaller spheres (caviar style)
The last sphere I made (with clear yuzu mix) had been left too long in calcium salt bath though, so it got harder and hard and bouncier, and I could pick it up and bounce it off the other table. Another thing to note is that jellification continues even after rinsing in cold water so no more liquid remains after a while. But throughout all this - it just tastes like Yuzu juice. Although all the liquid within the sphere will become jellified, sodium alginate actually doesn't add any appreciable change in flavor besides being a kind of thickener. Also, it doesn't really get harder than this sort of jelly unless you increase the concentrations, so I don't think there need to be too much concern when washing up, as a highly diluted form of the chemicals wouldn't hold up against a stream of water.
See another food experiment: Agarification - Bell Pepper Spaghetto