Chris and I finally got our hands on some calcium chloride (intended for food purposes rather than, you know, medical or aquarium purposes) so we can now do proper normal spherification instead of just reverse spherification!
With reverse spherification, the sodium alginate goes into solution in the bath and you put xanthan gum and calcium gluconolactate in the liquid you’re making into spheres and drop it into the bath. With non-reverse spherification, the sodium alginate goes into the liquid instead, and the bath is a solution of calcium chloride. Either way, calcium has to react with the sodium alginate to cause the gelling. Which method you use depends on factors such as the pH of the liquid (e.g. reverse spherification is better for acidic liquids).
Unfortunately, I didn’t realise how acidic pomegranate juice is when I decided to go with non-reverse spherification. It has a pH of about 3.2, so dropping it into the calcium chloride bath after it had been blended with sodium alginate resulted in the drops dissipating almost completely. Realising this must be the acid component, I added some sodium bicarbonate to neutralise the liquid a bit, and it then worked perfectly. Alas, of course this increase in pH also unfortunately took away most of the tartness of the pomegranate juice, which I had chosen for its tartness so it would offset the sweetness of the white chocolate. Never mind, I’ll just try reverse spherification for pomegranate in the future.
If you don’t have the equipment and ingredients for spherificating the pomegranate juice, the easiest substitute in this recipe would just be to add pomegranate seeds instead of the pomegranate juice spheres. Recipes after the cut.