Chef Ferran Adria experimenting in his kitchen workshop in Barcelona, Spain

AP Photo/Bernat Armangue

Spherification, Flash Freezing and Other MG Tricks

­Molecular gastronomists use ­special techniques, ing­redients and cooking principles to encourage certain chemical reactions to occur. These reactions, in turn, produ­ce startling new flavors and textures. One popular technique is cooking meat sous vide, a French term that means "under vacuum." Here's how it works: First, you pour water in a pan and heat it to a low temperature. The exact temperature varies depending on the type and thickness of the meat, but it never exceeds the boiling poin­t of water (212 degrees F, 100 degrees C). For steak, the water temperature will be about 140 degrees F (60 degrees C). Next, you place your meat, along with seasonings, into a heat-safe plastic bag, seal it and place it in the hot-water bath. The meat ­cooks slowly in the heated water and retains its moisture. After approximately 30 minutes, you remove the meat from the bag and place it in a hot frying pan. Sear the meat briefly on each side before serving. When you cut into the meat, you will find it to be juicy, tender and delicious.

An­other interesting technique is spherification, which involves making liquid-filled beads that, to use the words of a writer at Gourmet magazine, "explode in the mouth with a pleasingly juicy pop" [source: Abend]. Ferran Adrià, the chef of El Bulli Restaurant in Spain, first developed the technique and has since perfected it for a variety of dishes. Spherification relies on a simple gelling reaction between calcium chloride and alginate, a gumlike substance extracted from brown seaweed. For example, to make liquid olives, you first blend calcium chloride and green olive juice. Then you mix alginate into water and allow the mixture to sit overnight to remove air bubbles. Finally, you delicately drop the calcium chloride/olive juice mixture into the alginate and water. The calcium chloride ions cause the long-chain alginate polymers to become cross-linked, forming a gel. Because the calcium chloride/olive juice mixture enters the alginate in the shape of a droplet, the gel forms a bead. The size of the bead can vary dramatically, making it possible to create jelly-shelled equivalents of everything from caviar to gnocchi and ravioli.

Flash freezing can also be used to create fluid-filled fare. It's simple: Expose food to extremely low temperatures, and it will be frozen on the surface, liquid in the center. The technique is typically used to develop semifrozen desserts with stable, crunchy surfaces and cool, creamy centers. At Chicago's Alinea restaurant, chef Grant Achatz uses flash freezing to create a culinary delight consisting of a frozen disk of mango purée surrounding a core of roasted sesame oil. As a San Francisco blogger and food lover relates, the dish arrives with instructions: "We were instructed to allow the whole thing to melt away on our tongues. An extraordinary dance of sweet, tangy, salty, icy, creamy, oily ..." [source: Gastronomie].

Flavor juxtaposition is one of the most important tenets of molecular gastronomy. Hervé This says juxtaposition can be used to intensify a more flavorful ingredient by pairing it with a much less flavorful ingredient. Or, you can combine two dominant flavors, such as chocolate and orange, to reinforce the taste of both. Either way, understanding the molecules responsible for flavors is helpful. Molecular gastronomists have learned that foods sharing similar volatile molecules -- those that leave food as a vapor and waft to our nose -- taste good when eaten together. This concept has led to some unusual flavor pairings, like strawberry and coriander, pineapple and blue cheese, and cauliflower (caramelized) and cocoa.

­If you wan­t to test some of these techniques, you'll need the right equipment. On the next page, we'll review some essential tools of the molecular gastronomist.