Spherifying is a technique that, since 1946, has been used by the food industry. However, it was not until the beginning of the 21st century that this technique was seen popularized by the research work of Ferrán Adriá and his team of the restaurant El Bulli and its application to the world of gastronomy.
It seems that the word spherification makes many tremble, but those of you familiar with the concept will know that make a homemade spherification it’s not complicated. As with any new technique that we face in the kitchen, in addition to needing specific tools and a pinch of skill, we just have to follow the correct steps and that’s it.
What is a spherification and how can it be done at home?
Spherification is a culinary technique widely used in modern haute cuisine, belonging to molecular cuisine. By means of this technique it is possible to gel the outer layer of a liquid food, by means of the formation of a thin membrane, making it have the appearance of a solid substance, although inside it is liquid.
exist two basic ways of spherifying food, direct or basic spherification and reverse spherification. The technique to apply depends on the food and its chemical components. To spherify with either of these two techniques, it is necessary to use alginate, a purified substance from brown algae and responsible for gelling, and calcium chloride.
Alginate is only capable of gel at neutral pH values or pHs between 4 and 7. Gelation does not occur below 4, acidic solutions, or above 8, basic solutions. To stabilize the extreme pH values and achieve the required pH, it is necessary to use sodium citrate.
Types of spherifications
Direct or basic spherification
This technique applies to not very liquid foods. It is important to know that it does not work with dairy products, acids, fats or alcoholic beverages above 30º. The spheres that are obtained are small, similar to caviar.
The food to be spherified mixed with an alginate solution (5 g or 1/3 of alginate / kg of food or 2 g of alginate / 150 ml of liquid food) and beat with an electric mixer, allowing a few minutes of rest for the alginate to hydrate well. It is important that the bubbles produced by the shake disappear so that the spherical shape is perfect.
A bath with water and calcium chloride (for 1 liter of water: 10 g of calcium chloride / kg of food or 4 g of calcium chloride / 500 ml of liquid food). With the help of a jar we drop drops of the first mixture in this bath. After a minimum of 30 seconds and a maximum of three minutes, they are removed and rinsed in water to eliminate the calcium chloride flavor that they may have acquired.
The container where the calcium chloride solution is located must be deep enough to allow gelling of the exterior to occur before the spheres reach the base. In this way the perfect roundness of the spheres is achieved and, aesthetically, they are more pleasant.
With this technique, larger spheres are obtained than those obtained by direct or basic spherification, liquid inside, which produce an amazing effect in the mouth. Applies to liquid foods: rich in calcium (either its own or due to the addition of calcium gluconolactate), acids, rich in fats or with a high alcohol content.
If the food to be spherified contains added calcium In the form of calcium gluconolactate (2% of the weight of the food), the presence of xanthan gum (2 g) is also needed to increase the viscosity of the food to be spherified and for it to take place correctly.
If the food to be spherified is acid (fruit juices or similar) it is necessary to add sodium citrate so that its pH range is optimally balanced and spherification occurs properly.
In this case, the feed mixture is directly immersed in a water and alginate bath (1 l of water / 5 g of alginate). The alginate gels around the mixture, forming a thin solid outer membrane and maintaining a liquid interior. The gelling does not evolve over time, as in the direct or basic, so it is not necessary to keep an eye on the clock. However, two minutes of bathing are sufficient.
The spheres are removed from the alginate bath and passed through a rinsed with water, to eliminate the traces of alginate flavor and avoid that the flavor of the spherified food is diminished.
There are many spherification kits on the market that contain everything necessary to carry out this technique and achieve perfect spheres, either by direct or reverse spherification. Our guidelines on how you can make a homemade spherification and the right tools are all you need to become expert spherifiers. Take heart for it!
More information | A biologist in the kitchen
Images | Joselu Blanco and Javier Lastras on Flickr, Azurmendi on Pinterest
Directly to the palate | Spherification, a spectacular culinary technique
Directly to the palate | Culinary techniques