Welcome to the ChefSteps spherification course! If you haven't <a href="/recommended/spherification-kits">purchased a kit yet</a>, that is the easiest way to get started with these activities. Now let's begin with the simplest technique, reverse spherification.

Reverse spheres are made using two components: a flavorful liquid that contains a calcium salt, and a spherification bath that contains a hydrated gum, like alginate, that will gel instantly in the presence of calcium ions. When you pour a spoonful of the flavorful liquid into the spherification bath, the liquid draws itself into a nearly spherical shape. As the sphere sinks, calcium ions at its surface cause a membrane of alginate to gel, encapsulating the flavorful liquid sphere.

So why is it called reverse spherification? Because it's the opposite of direct spherification, in which the alginate is hydrated in flavorful liquid, then dropped into a setting bath containing a calcium salt. That turns out to be a more limiting approach. Not only must you pay attention to the pH and natural calcium content of the flavorful liquid, but the resulting spheres can be no larger than caviar-sized droplets.

With reverse spherification, it's possible to make much larger spheres. The liquid-center itself doesn't contain anything that will gel, so the sphere can never become entirely solid. Thus, spheres prepared this way can be kept indefinitely.

Reverse Spherification

An alginate spherification bath is used for either reverse or frozen-reverse spherification. By hydrating alginate in water that contains almost no dissolved calcium, the alginate won't gel. But once a liquid that contains calcium ions is dropped into this bath, the alginate instantly begins to gel around this liquid as it reacts with the calcium. When done with care, the result is nearly spherical. The longer this sphere of liquid remains in the alginate spherification bath, the thicker the surrouding skin becomes.

Alginate Spherification Bath

The aroma of the young needles from fir trees is a surprisingly delicious Pacific Northwest flavor. In the early spring, you can collect the buds from fir trees and use them to make extracts and syrups. We use a fir essential oil in this recipe because it is a food-grade product that's easy to find. 

Try serving the spheres with smoked fish or oysters. Or gin and lots of lemon or lime.

See [Reverse Spherification](https://www.chefsteps.com/activities/reverse-spherification), part of our [spherification course](https://www.chefsteps.com/courses/spherification), for details on this technique.

Pine Spheres

Frozen-reverse is a refinement of [reverse spherification](https://www.chefsteps.com/admin/activities/reverse-spherification). By first freezing the flavorful liquid in a mold, it is much easier to prepare many spheres at once, all with a perfect shape. For this reason, it's our preferred technique. It works exactly like reverse spherification, except that you drop hemispheres of your frozen liquid into a warm alginate or Sphere Magic bath. As the frozen hemispheres begin to thaw in the warm spherification bath, a perfectly thin encapsulating gel forms around them.

Frozen Reverse Spherification

We see you a beet salad with goat cheese and raise you a beet sphere with frozen goat cheese shavings. It seemed only logical to evolve this classic flavor combination into a modernist amuse bouche with the help of spherification. Instead of cooked beets, we created a sphere of beet essence—at its core, beet juice—which we paired with goat cheese, frozen and shaved thin. <a href="http://ma.tt">Matt Mullenweg</a>, founder of <a href="http://wordpress.com/">Wordpress</a> and <a href="http://automattic.com/">Automattic</a>, and <a href="http://www.fourhourworkweek.com/blog/">Tim Ferriss</a>, best-selling author of <a href="http://www.amazon.com/gp/product/0547884591/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&amp;camp=1789&amp;creative=9325&amp;creativeASIN=0547884591&amp;linkCode=as2&amp;tag=delvkitc-20">*The 4-Hour Chef*</a>, joined us in the kitchen for an afternoon of hands-on spherification training and became instant converts. You can learn the technique of [Frozen Reverse Spherification](https://www.chefsteps.com/activities/frozen-reverse-spherification), which is part of our free [spherification course](https://www.chefsteps.com/courses/spherification).

Beet Sphere and Goat Cheese

Direct spherification is a way to create small, caviar-sized spheres that pop in the mouth with an intense burst of flavor. They’re whimsical and fun. The technique was pioneered by Ferran Adrià at el Bulli in 2003, who spherified melon juice to give it the appearance and texture of caviar.

The related techniques of [reverse](https://www.chefsteps.com/activities/reverse-spherification) and [frozen-reverse](https://www.chefsteps.com/activities/frozen-reverse-spherification) spherification were developed at el Bulli in subsequent years. All of these methods work because alginate gels upon contact with calcium ions. In direct spherification, alginate is added directly to a flavorful liquid. This solution is then added drop-by-drop to a setting bath that contains calcium. As the calcium ions interact with the alginate, a flexible skin forms around the drop. 

The concept is simple, but there is an art to achieving good results with this technique.

Direct Spherification

A calcium solution is used as a setting bath for direct spherification. When the flavorful liquid containing alginate is dropped into the setting bath, the calcium causes alginate at the surface of the droplet to gel instantly. The longer the spheres remain in the calcium bath, the firmer they will become. Usually 10 to 15 seconds is an adequate contact time for spheres that will pop in the mouth. The spheres should always be rinsed in fresh water before being served to wash away any bitter taste imparted by the calcium chloride.

Calcium Spherification Bath

Chocolate and caviar may not seem like a match made in heaven, but what if the chocolate _is_ the caviar? Using the modernist technique of direct spherification, we take liquid cocoa and turn it into caviar-like spheres that burst with rich chocolatey flavor. See [Direct Spherification](https://www.chefsteps.com/activities/direct-spherification), part of our [spherification course](https://www.chefsteps.com/courses/spherification), for more details on this technique.

Chocolate Spheres

The idea of exploiting spherification-like techniques for food production was first patented in Britain in 1942 by William Peschardt, a food scientist working for the firm Unilever. Since then, the technique—using ions to trigger a gelling process–has found a variety of uses in the food industry. One common use is to stuff pitted olives with what appears to be a sliver of pimento but is in fact pimento juice that's inserted into the pitted olive and gelled by calcium already present in the olives.

It was Sergi Estragues and Joachim Vives, representatives of a Spanish food company, who initially demonstrated the technique to Ferran Adrià. He put it to far more creative and surprising uses at his restaurant el Bulli. It seems simple enough, but, as many chefs have discovered, mastering the art of spherification requires a deeper understanding of how technical ingredients like sodium alginate interact with the other ingredients in a recipe. 

Here we explain some of the most important principles to keep in mind when creating your own spherification recipes.

The Science of Spherification

More Resources

Spherification is kitchen alchemy, a technique that enables you to imbue a flavorful liquid with the appearance of being solid, an illusion that’s broken when the spheres burst with flavor as they’re eaten.<br/><br/>ChefSteps’s course on spherification will help you prepare dishes that surprise and delight your family and friends by making the impossible possible in your kitchen.<br/><br/>Enroll with ChefSteps for helpful step-by-step demonstrations of the relevant techniques, use our reliable recipes as a starting point, and get the support of a friendly community of experienced cooks and world-class chefs who will answer your questions.

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