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.
Pomegranate and cherry caviar
125g pomegranate and cherry juice (I used POM brand)
1g sodium alginate
1/2 tsp sodium bicarbonate (bicarbonate of soda, baking soda)
3.25g calcium chloride
Blend the juice and sodium alginate using a stick blender. Add the sodium bicarbonate and blend again. This will change the consistency to a thin gel. Leave to stand for half an hour so the air bubbles rise to the surface.
Stir the calcium chloride into the water to dissolve.
Suck up the juice mixture from the bottom of the container into the syringe (avoiding the top portion of the liquid where air bubbles may still be caught). Use the syringe to drop small droplets of the juice into the bath so they form spheres. Do about 20 or 30 of these spheres, leave them for about a minute in the bath, then scoop them out using a strainer spoon (one with small holes in it). Dip the spheres into an extra bath of plain water to wash them, then put them in a bowl while you make more spheres. Continue until you have used up all the juice to make spheres. It makes about 2/3 of a cup of spheres.
White chocolate kirsch mousse
This recipe. Just as you finish folding the chocolate into the whipped cream and it is almost totally combined, add the spheres (if necessary, drain the spheres directly before adding to the mousse by carefully pouring them into a sieve). Leave the mousse to set either in one big serving bowl or in individual containers.
I made these into little individual servings in cups for a get-together, and everyone seemed to really enjoy them. The mousse (by Heston Blumenthal) is amazing just by itself so the whole recipe this time was pretty much guaranteed to get a thumbs up.