We All Scream
By Maria Reidelbach
An amazing, favorite treat we all enjoyed before memory, I think we take frozen desserts like ice cream and sorbet for granted. Despite being one of America’s most common desserts, ice creams, sherbets, sorbets, gelatos, granitas, ices and their friends are the most magical of foods—on a hot summer day they are a cold, solid substance that literally melts in your mouth into an ambrosia of delightful flavors, sweet, tart and aromatic.
Although the chemistry of making a frozen dessert is quite amazing, we are lucky that the ingredients and process can be incredibly simple. This is a dessert that can easily be made entirely of local ingredients—a yardavore grand slam! You can make classics like strawberry ice cream or raspberry sorbet, unusual treats like elderflower ice, red currant sherbet or black walnut custard, or use fun combinations of fruits, herbs and other flavors to make desserts like peach-bay leaf gelato or wild ginger-honey popsicles.
Making a frozen dessert is something that is fun to do with kids and a great way to learn a little applied science with a treat at the end. Even though there is fancy and complicated equipment to do the job, you can make great ice cream without any special gear at all.
Early frozen desserts were made using a discovery from the Muslim world. In the 13th century Arabic scientists discovered that adding saltpetre to water lowers its temperature. During hot summer days, sweltering desert-dwellers would chill their drinks in a bath of saltpetre and water, similar to chilling wine in an ice bucket. Drinks were made with sugar syrups flavored with fruits, spices, and even flowers. They call this syrup “sharbat,” pronounced by the Turks “sherbet.” Medieval Italians adopted the same technique to cool wine (natch!), and then figured out that if you mixed the saltpetre, or even plain salt, with snow or ice (brought down from the Alps), it dropped the temperature below freezing. Using this mixture for the bath, they were able to freeze sharbat mixtures, making the first sherbets and sorbets (from the same Arabic root word). Soon inventive Italian chefs added milk, cream and eggs for a full range of frozen delights.
Until the 19th century, these fantastic treats remained expensive and rare. Making a frozen dessert was a difficult small-batch procedure until Nancy Johnson, a Philadelphia inventor, patented a crank device using a cannister, paddles, and that ancient ice and salt bath in 1843. Later, the design was refined to make the cannister rotate. It is almost identical to the manual ice cream makers still in use today!
The difference between a hard block of ice and a delightful frozen dessert is texture, and you can control this in a variety of ways. One is by adding substances that disrupt crystal formation that make ice so hard, and—hallelujah!—sugars, including maple syrup and honey, work well for this, as do fats, like cream, egg yolks, coconut milk or even avocado, and also alcoholic liquids. Another way to create a smooth texture is by keeping the mixture moving while it’s freezing. You can play with both of these variables to create many different textures.
One of the lowest tech ways to make sorbets, sherbets and ice creams uses only ziplock plastic bags, ice and salt. Make a pint of your mixture, pour it into a quart bag, seal it and completely chill it. Get a gallon bag and dump a couple of ice trays in it plus half a cup of salt. Put the small bag in the large bag and seal it. Now, insulating your hands with gloves or a towel, shake the whole thing (or have a kid do it), checking the texture of the dessert through the bags every few minutes. When it’s firm enough, remove the small bag from the larger bag, squeeze it into bowls to serve. Voila!
Basic Recipe for Frozen Desserts
4 cups of fruit puree
1 cup of sweetener: maple syrup, honey, corn syrup, sugar or a mixture of these
1 tablespoon of lemon juice or vinegar, unless your fruit puree is very tart
Make your fruit puree by blending or mashing nice, ripe fruit. It’s up to you if you want to peel the fruit or strain the mixture to make it smoother.
You can add a cup of liquid—water, herb or spice infusions (tea), milk, cream, coconut milk, egg yolks or anything you can dream up. Frozen foods dull taste buds, so make your flavors a bit stronger than you would think.
The amount of sugar in your mixture will have a great effect on the final texture of your dessert—if you don’t have enough sugar, it’s going to be hard as stone. Fruits and sweeteners vary wildly in the amount of sugar they contain. If you want to test the sugar level in your mixture, float a clean egg in it. Ideally, an area the size of a nickel will be exposed. Sugar makes liquid heavier, so the sweeter your mixture is, the higher the egg will float. Add sweetener or liquid of choice until your egg is floating just right.
Now, freeze your dessert as desired: pour it into popsicle molds for dessert-on-a-stick; freeze in an open pan, then rough it up with a fork for granita; or for a smooth ice cream or sorbet, use the plastic bag method or an ice cream freezer. Almost always, you’ll have a fantastic, fresh-tasting treat. Like all magic, occasionally something will go to hell and you’ll have a lump of hard ice, or a squishy liquid that refuses to firm up. In this case you can melt it, tinker with ingredients and try freezing it again. Or you can add a straw and serve it as a slushy or turn it into a mixed drink and try again another day.
Strawberries + elderflower syrup + cream
Raspberries + lemon balm or lemon verbena infused milk + honey
Blueberries + peaches + maple syrup
Maria Reidelbach is an author, artist and local food activist who lives, works and eats in Accord, NY.