Sorbet Science: Top Tips for Making a Refreshing Frozen Dessert

As soon as the spring birds begin chirping and temperatures creep into the sweater-free zone, my eager longing for the season’s bounty of produce results in gross overbuying.

Perhaps you have the luxury of a lush garden or you stock up at the local market – whatever the case may be, chances are that in the coming months, you too will find yourself hoarding mountains of ripe produce.

What better excuse to make a fresh batch of homemade sorbet?

While the premise of sorbet is quite simple – just a frozen puree of fresh fruit – learning to master the smooth, scoopable texture can be overwhelming. Delicate ratios of sugar, water, fiber, and pectin can all affect your end result.

Save investing in a refractometer or destroying your wholesome treat with unwanted chemical stabilizers, is it possible to achieve professional-grade sorbet at home?

Armed with just a bit of food science, you can successfully transform all your quickly-ripening produce into the perfect afternoon treat.

What Makes it Work?

At its most basic, sorbet is comprised of three things: fruit, sugar, and air. Almost any fruit can make a successful, smooth frozen treat, but not without a few small adjustments, according to fruit family.

The lack of fat makes the other ingredients a tad more finicky than working with an ice cream. In order to decipher the adjustments needed, it is important to understand the role of sugar and air.

Sugar is a magical ingredient. Amidst masses of nutritional guidelines warning of its ill effects, the wonder of sugar’s scientific properties is oftentimes lost. But understanding sugar is key to achieving the perfect texture.

As the percentage of sugar in a liquid increases, the freezing point decreases. Since sorbet is primarily made of sugar and water, hitting the correct ratio will determine whether you end up with a block of ice, a sloppy mess, or that sweet spot in between.

When spinning the fruit puree, your machine is not just bringing the temperature down – it is incorporating a lot of air. This air adds volume to the sorbet while decreasing the size of the ice crystals that form as the water in the puree freezes. If the ice crystals get too big, your otherwise lovely snack will fail to melt smoothly in your mouth.

Two Methods

There are two main methods that you can use to turn your fruit into a spinnable puree. The simplest involves blending simple syrup with fruit.

Simple syrup is equal parts sugar dissolved in water. While it is easy to just buzz your fruit and syrup together, the high volume of water increases the potential for icy crystallization, which can hurt your end texture.

The second method involves macerating your fruit in sugar, then processing it into a puree. In under an hour, sugar breaks down the fruit, creating its own liquid rather than requiring the addition of water. This is my preferred method, as it results in a smoother finish.

The Sugar Ratio

The ideal sorbet has a sugar percentage between 20 and 30 percent. Since you most likely don’t feel the need to purchase a special tool to measure the sugar content of your fruit, the safest way to start is with a ratio of 5 parts fruit to 1 part sugar.

For the simple syrup method, this would mean 5 cups of fruit and 2 cups of syrup. For the maceration method, use 5 cups of fruit and 1 cup of sugar.

The easiest way to blend the base is with an immersion blender, though a food processor or basic blender will work too.

If you’re looking for an immersion blender for your own kitchen, check out Foodal’s guide here.

Once your puree is blended, you can test your sugar level with an egg. At the ideal viscosity, a raw egg will float perfectly in your base. It may sound crazy, but it really works!

Wash and dry an egg, lower it carefully into your fruit puree, and check to see if it floats. If not, incorporate additional sugar or simple syrup, lest you end up with just a colorful chunk of ice.

Glucose syrup, corn syrup, or invert sugar can improve the texture of the final sorbet, and also help to keep it from freezing solid.

In these syrups, sucrose has been broken down into glucose and fructose. They have more body than simple syrup and resist crystallization. Try exchanging up to 1/2 cup of sugar with glucose or corn syrup.

Alternative sweeteners such as honey, agave, or maple syrup will not upset the sugar ratio – however, their stronger flavors might overpower your fruit. If you plan to use an alternative sweetener, don’t replace all of the sugar. Try using 1/4 cup of the alternative with 3/4 cup of sugar.

Use the egg test to check your sugar and liquid ratios! If the egg sinks, you can add either granulated sugar or your syrupy alternative – just taste as you go to ensure that your alternative does not mask the flavor of the fruit.

Artificial sweeteners will not work in sorbet as they do not contain any sugar, and thus will not impart the important chemical properties necessary for creating the treat’s structure. If you are concerned about added sugars, try making a fruit-only alternative like a frozen Yonanas puree.

Fruit Families

The volume of fiber in your fruit can affect the end result. Fruits with higher fiber contents will lower the water content of the puree, allowing it to freeze with less interference from ice crystals.

For this reason, stone fruits and berries make for great starter sorbets. Tart green apples or fleshy mangoes work nicely as well. The presence of fiber will create a thicker puree, which will result in a smoother sorbet without the addition of stabilizers.

Some other excellent fruit options include:

• Cherries
• Kiwi
• Nectarines
• Peaches
• Pears
• Pineapple
• Plums
• Kiwi
• Strawberries

Rhubarb also makes a nice sorbet, however, it is important to cook the vegetable after macerating with sugar in order to help break down the stalks, cut the acidity, and develop its wonderful earthy, tart flavor.

But who doesn’t love the tang of lemon, or vibrant blood orange? When working with citrus, pay particular attention to the sugar content.

The lack of fiber in citrus juice means the water content will be very high. Using enough sugar is vital to avoiding an icy end result. This is where the egg test really comes in handy. If the egg floats, you’re good to go!

You can also eliminate the likelihood of rock-hard sorbet with the addition of a natural stabilizer.

Stabilizing Add-Ins

So, you’ve made a lovely sorbet. You’ve allowed it to set in the freezer for an hour or two, and it graces your tongue with the smoothness of ice cream.

The next day, you go back for seconds only to discover that the once-delicate dessert is now stiff enough to break a spoon.

Over time, the air you so carefully churned into the sorbet begins to deflate. This affects the eating experience significantly. One option is to allow the sorbet to melt in the fridge overnight and simply re-churn.

But if you don’t care to add the extra effort of re-freezing, another option is to incorporate a stabilizer into the original base. The three best options are alcohol, pectin, and gelatin.

A few tablespoons of liquor not only brings an additional complexity to the dish, it lowers the freezing point, which inhibits the final product from turning into ice. Be careful not to add more than a tablespoon per cup of base, or else the freezing point will be so low you’ll end up with a cup of slush!

Lower alcohol additions like wine or sake offer a bit more leeway, but be aware that this also means they increase the water content of your base. With these, try using up to two tablespoons per cup of base.

Some fun pairings include:

• Cucumber and St. Germaine (get the recipe here!)
• Peach and Chardonnay
• Pineapple and Rum
• Plum and Cabernet
• Grapefruit and honey

Fruit pectin is another easy to use, natural stabilizer – particularly useful when working with citrus. Since citrus juice has such a high water content and it’s low fiber, pectin will bring a bit more viscosity to the juice, decreasing the size of your ice crystals.

Use 1 teaspoon of pectin per quart of juice. It is necessary to boil the pectin with sugar for one full minute to ensure that it is properly hydrated.

If you’re making a quart of citrus sorbet, boil 3/4 cup sugar, 1/2 cup water, 1/2 cup citrus juice, and 1 teaspoon fruit pectin for one minute. After cooling, stir in the remaining 3 cups of citrus juice and churn.

Boiling will alter the flavor of the juice a bit, which is why I say to only boil part of it. I typically avoid adding extra water wherever possible, because it means cutting the flavor and increasing the size of the ice crystals. You also need to boil some acid with the sugar to activate the pectin, so using the fruit juice accomplishes this.

Pectin can be purchased in powdered form at most grocery stores, or anywhere that you can buy canning supplies. Another option is to add a few tablespoons of fruit jam or jelly, since these already contain a small amount of pectin.

Gelatin is another handy stabilizer. It adds great body to the base, which significantly reduces the size of the ice crystals that develop during freezing. 1 teaspoon of powdered gelatin or 2 sheets of sheet gelatin can improve a quart of base.

Bloom (soften) the gelatin in 1/4 cup of water or juice. Heat 1/4 cup puree or juice, and stir into the bloomed gelatin to dissolve. The fruit just needs to be heated enough to dissolve the gelatin, so it doesn’t need to come up to a boil.

The gelatin could be dissolved in water instead if you choose, but I always try to avoid adding water as much as possible. Let cool on the counter for half an hour, then add to the remaining sorbet base, chill, and churn.

Churn, Baby, Churn

Congratulations, you are now fully equipped to make your own batch of sorbet! With so many fruit options springing into season, the variations are endless.

Once you’re comfortable transforming your fruit into a stable base, you can experiment by adding additional layers of flavor like balsamic vinegar, fresh thyme, or spicy cayenne.

If your mouth is now watering for this tasty homespun snack but you’ve yet to invest in an ice cream maker, be sure to check out our guide to choosing the best on the market!

You know what’s really similar to sorbet? Sherbet! Check out one of our favorite recipes here.

Photo credits: Shutterstock, except where otherwise indicated. Photos by Kendall Vanderslice, © Ask the Experts, LLC. ALL RIGHTS RESERVED. See our TOS for more details.