So this is a topic that I’ve refrained from writing about because it is one of the most intimidating. The topic at hand is spherification. I’ve decided to break it up into two… possibly 3 separate articles. This first article will focus on the ingredients and the method of direct spherification. Making spheres can be intimidating and unforgiving at first. Very few people who attempt spherification for the first time will have success. There are many little variables that can ruin your spheres and in return ruin your day. But once you know what bases to cover, spherification will become a very simple and rewarding task. Without fail, every week the same question will come across my desk (prep table). I’ve explained it more than any other modern cooking method. That questions is…
“How does spherification work?”
Direct spherification in its most simple form is encapsulating a flavorful liquid in a thin edible gel. But making that gel is the tricky part. The gel is possible because of sodium alginate. Sodium alginate on its own does not create a gel. Sodium alginate is a thickener that is commonly used in commercial pie fillings. Adding sodium alginate to liquid in a ratio of 0.5-0.7% to the total weight, will thicken your flavorful liquid slightly. Here comes the fun part, when sodium alginate comes in contact with calcium it will begin to gel immediately. Now that sodium alginate has been added to the liquid it will have microscopic strands floating around freely, these are called polymers. When calcium comes in contact with these polymers it instantly begins bonding these polymers together. When these polymers bond they create a gel. Sodium alginate bonds with calcium, so do not attempt to make it with a calcium rich liquid. Beware of store bought juices as they are often fortified with calcium. Also if you add water to your recipe, your tap water most likely contains calcium. For this use distilled water If you are unsure and believe your liquid could contain calcium. There is a fix for that by using the ingredient called sodium hexametaphosphate. Sodium hexametaphosphate is a sequestrant, what that means is that it covers up calcium ions so they cant gel the sodium alginate. Another issue that will affect your spheres is acidity. If your liquid is below 4.0pH it will not allow the gel to set. The best fix for this is to add, sodium citrate to any acidic liquid in a ratio of 0.8% to the total weight. Besure to add the sodium citrate before adding any sodium alginate. Sodium citrate is a buffering agent, and will raise the pH to the proper levels. Follow all these steps and your flavorful liquid should be ready to use. Sodium alginate comes in a few different forms, but mind you they can all be used for spherification. The three are sodium alginate, perfected sodium alginate, and sphere magic. The biggest difference between the three is how long it takes to fully hydrate. Think of hydrating as a term for fully mixing into the liquid after blending. Sodium alginate can take up to 24 hours to fully hydrate. Perfected sodium alginate will take 1-2 hours to fully hydrate. Sphere magic is a partially hydrated product and should be used a ratio of 1-1.4% of the total weight of the liquid. Sphere magic takes only 10-20 minutes to fully hydrate and can be whisked into the liquid rather than having to use a blender.
The second part is very simple making a calcium bath. You will need to add calcium to some water. In this case tap water will suffice. The calcium we suggest is calcium chloride. Calcium chloride should be used in a ratio of 1% to the total weight of the water. My general rule of thumb is 1L of water to 10g of calcium chloride. Whisk the calcium chloride into the water and allow it to dissolve. The only thing to look out for here is calcium chloride has a bitter flavor. Once the spheres are set you will need to rinse them off in a second bowl of fresh water.
Making the spheres will happen in 2 forms small pearl sized spheres known as caviar, and larger teaspoon sized spheres called ravioli. The caviar sized pearls can be made through various means. Caviar syringes such as the perfect caviar maker, will allow you to make spheres 1 by 1. This is great for starting out and make a few dishes. But if you want to make an abundance of spheres you will need to use something like the rapid caviar maker or the spherificator. These machines will allow you to make 100’s of spheres in a short amount of time. This is great for dinner parties, commercial kitchens, and catering. For caviar you will need to allow them to sit in the setting bath for 30 seconds before removing and rinsing. For the ravioli sized spheres allow them to set for 2 minutes before removing and rinsing.
To store the spheres place them in a container of the flavorful liquid. Make sure this flavorful liquid does not contain sodium alginate or the calcium in the thin gel with begin to set the storage liquid. One downfall of direct spherification is that the calcium will continue to gel the sodium alginate until your spheres are completely solidified. Now there is a way to make spheres where they will never solidify but that’s an article for next time.
Give our Savory Shallot Sphere recipe a try! Spherification is a versatile technique that can encapsulate any flavor. In this recipe we created savory caviar that can top any dish with a concentrated caramelized flavor that is at once mild and sweet.