Cherry-Raspberry Orbs and Spherification
A very popular technique in modern fine dining is spherification. This technique allows us to encapsulate a liquid, such as cherry and raspberry puree, inside of itself. The key players are calcium and sodium alginate, which is a seaweed-derived gelling agent. When sodium alginate comes into contact with calcium it quickly forms a delicate but resilient skin that cannot be de-natured by freezing or excessive heating. However, when you apply light pressure to the orb with a fork or your teeth, the membrane breaks, releasing the liquid interior. This is illustrated in the photo below.
I made these orbs by first making a cherry and raspberry puree. I then thickened and seasoned the puree. I added calcium lactate to the puree and froze the mixture into spheres. Meanwhile I combined water, sugar, and sodium alginate to make a slightly sweet mixture. I boiled the mixture to expel the air bubbles and kept it warm. I dropped the frozen spheres into the warm alginate bath. The heat melted a thin layer of water on the outside which was immediately gelled. After a 2 minute soak, I carefully removed the orbs and rinsed them in a water bath. I then transfered them to a holding bath of cherry juice. Although the skin is resilient to heat and cold, it breathes and is permeable by the process of osmosis. Keeping the orbs in a flavored liquid adds to the overall flavor and prevents liquid migration from the orbs.
Top left to lower right: Frozen puree, spheres in hot alginate bath, spheres in water rinsing bath, spheres in cherry holding bath.
For a complete recipe with helpful information on where to buy and how to use sodium alginate and calcium lactate, please subscribe to my bi-weekly mailing list. Simply click the link below, enter your email address, and I will include the recipe in my next mailing (12/1/09). You can unsubscribe at any time and I will not flood your inbox. With each mailing you’ll receive a friendly update of what’s going on at Garrett’s Table with exclusive, subscriber-only recipes and content.
Stay tuned in the coming days to see how I use these cherry-raspberry orbs with the flavors of a classic New York pastry
Photos by Justin Kern.
4 comments
Hi Garret, this is so intriguing… Molecular Gastronomy! This looks like a rather firm sphere. I have seen a bartender do something similar but the orbs were more fluid - like mercury. Are the ingredients accessible?
that looks fantastic!
I just got the silicone sphere molds from chicago molding yesterday in the mail. I’m looking very much forward to giving the butter spherification another shot (it eludes me, somehow!).
I would be interested in seeing how much calcium lactate you add per ml of cherry juice, since the reverse spherification (as you’ve got here) is typically used more for calcium-rich foods.
Shirley,
The ingredients are very accessible through online retailers like lepicerie.com and willpowder.net. Don’t order much because a little bit goes a long way!
Kristie,
This indeed is “reverse” spherification although it shouldn’t be called that since it works much better to add calcium to the liquid and immerse it in an alginate bath. The alginate can add an undesirable flavor if you added it to the cherry puree and it has a dumbing effect on all seasonings. The alginate bath is slightly thick, prevents the frozen orbs from contacting the bottom surface of the pot and aids in creating a perfect membrane around the sphere.
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