The spherification technique, created by molecular gastronomy Chef Ferran Adria in 2003, consists of a controlled jellification of a liquid which forms spheres when submerged in a bath. There are a few variations of the spherification process: Basic Spherification, Reverse Spherification and Frozen Reverse Spherification.
Frozen Reverse Spherification is pretty much the same process as Reverse Spherification but with an extra freezing step. Freezing the main ingredient in hemispheric silicone molds reduces the preparation time, does not require practice and results in perfectly shaped spheres of consistent size. The hemispheric silicone mold is included in the Molecular Gastronomy Essentials Kit, the Molecular Gastronomy Premium Kit and the Molecular Gastronomy Ultimate Kit.
As in Reverse Spherification, this technique consists of submerging a liquid with calcium content in a bath of sodium alginate. But instead of using a spoon to pour the main ingredient into the alginate bath, a hemispheric mold is used to freeze the calcium mixture and then the frozen hemispheres are popped into the bath. As the edge of the hemisphere starts to melt, the calcium in the mixture reacts with the alginate in the bath to produce the membrane. After removing the spheres from the alginate bath, they are rinsed in a clean water bath.
The length of time that you need to leave the sphere in the bath is a little longer than in Reverse Spherification and it depends on how fast the frozen hemisphere thaws. To speed up the process, you can use a warm bath. If you use a warm alginate bath it can take from 2 to 5 minutes for the membrane to form.
Creating a perfect sphere using a spoon is an art and it takes time and patience (read 10 Tips to Create a Perfect Sphere). With Frozen Reverse Spherification, all the spheres will be the same size and perfectly round. Preparation time is shorter but you need to be able to prepare the mix in advance and allow it to freeze in the mold for several hours. Another benefit is that it is not necessary to thicken the main ingredient to create the spheres thus having a better release of liquid in the mouth when the sphere breaks. You may still want to slightly increase the viscosity so they can hold the spherical shape better when plated. The hemispheric silicone molds are perfect for frozen reverse spherification (buy silicone mold).
The only limitation of this technique is that you can only use it with ingredients that can freeze or do not get spoiled by freezing. So this technique wouldn’t be appropriate for alcoholic preparations for example. And of course, you need a silicone mold of bite size hemispheres. You can collaborate by getting the hemispheric mold from our store or one of our Molecular Gastronomy Kits so we can keep adding recipes and techniques. Thank you in advance!