Many books exist about ice cream that explore methodology and technique—the how of making top-notch ice cream. Rare is the tome that explains the science behind it, the careful engineering and balancing act required to produce a rich, creamy, and consistent product. One reason may be that the science behind ice cream is more complicated than it seems.
In James Beard Award-nominated pastry chef Dana Cree’s debut book, Hello, My Name Is Ice Cream, her first recipe doesn’t even appear until page 50. She spends much of the book’s first section exhaustively breaking down ice cream to its molecular level—a balancing act involving ice, fat, protein, and sugar, plus air. It’s a fascinating and scholarly read on one of the simplest pleasures of life, and how to use your newfound knowledge to produce the most delicious end product.
Watch Dana Cree make her key lime pie frozen yogurt on A.V. Club Live.
Dana Cree: We learned the ins and outs of ice cream manufacturing, from standards and practices, to how to clean your equipment, new legislation on ice cream safety, how a continuous-feed ice cream maker creates ice cream versus a batch freezer, and the flow of milk through a pasteurizing system. It had much less to do with making ice cream like we do at home, and much more to do with how ice cream is manufactured by dairy plants. Which was very interesting to me! They also touched on the physics and chemistry of ice cream—how stabilizers and emulsifiers function at a molecular level, the legal requirements behind labeling your ice cream. And there were some courses with more levity, like the workshop on vanilla, and a trip to the barns to visit the cows. They have a cow with a giant plug in their side, so they can reach in and check digestion in the rumens when they study feed.
AVC: What’s the most interesting fact about the science of ice cream you learned while writing this book?
DC: The most interesting thing I learned is that ice cream is a liquid, a solid, and a gas at the same time. Once I realized that, it made sense why the texture is so hard to perfect. Getting all three states of matter to stay put requires incredible balance.
AVC: In the book you talk about the role that color plays in ice cream and the various food coloring you’ll employ. Why is color so important?
DC: Flavor is more than just taste. Taste is the information we receive from our taste buds on our tongue, which is really only five things: sour, sweet, bitter, salty, and umami. But flavor is defined by all our senses, from the thousands of aroma compounds in food we perceive through our olfactory gland—ever wonder why you don’t perceive flavor when you have a stuffy nose?—to the way texture feels in our mouth, to the sound, or lack thereof, when we eat. Our eardrum is so close to our mouth it would be impossible for us to eat and not use our sense of sound.
But our eyes are the first sense we collect information about food from, and the color of food helps us predict what the flavor is going to be. So we eat with our eyes first, always, and color is the strongest indicator of what that flavor will be. The power of color in our food is so strong, it can mislead us, and often we can’t identify a flavor without seeing the color first, like when you are blindfolded and can’t tell the difference between Coke and 7Up. By adding color to our neutral ice creams, we help the person eating it identify the flavor in a very pretty way.
AVC: I’ve seen a lot of scientific explanations discussing the difference between ice cream, gelato, frozen yogurt, and frozen custard. Can you explain the differences between them, but from a taste and culinary perspective?
DC: From a taste difference, gelato is creamier, smoother, and softer. From a culinary standpoint, gelato—it’s made with a different machine that churns it with less air, and the base has less fat in it. Because it’s denser, it feels creamier without there being more cream in it. It is also meant to be eaten right after it’s made, like soft serve, before it hardens up. So it’s a little warmer than ice cream, allowing you to taste the flavors more rapidly.
Ice cream is firmer from a taste standpoint, the kind of scoops you can bite into, and is very rich. Flavors tend to linger when you eat ice cream. From a culinary perspective, ice cream is higher in butterfat, and is churned with more air into it. Ice cream is then hardened overnight. Because it’s hardened first, rather than eaten the day it’s made like gelato, it often contains add-ins, like ribbons and chunks and nuts, since it sets overnight and can rest in place as the ice cream sits in your freezer.
From a taste standpoint, frozen custard is the thickest, most dense soft-serve ice cream you’ll ever eat. Like gelato, it is eaten the day it is made, but even faster, as the frozen custard is extruded directly into a serving cup. And like ice cream, frozen custard often contains add-ins, which are folded into the thick frozen custard to order, and are often called concretes. From a culinary standpoint the texture of frozen custard is entirely dependent on a frozen custard machine, which churns the frozen dessert with next to no air in it.
Frozen yogurt is a split topic as there are two styles—the frozen yogurts in my book are just like ice creams that highlight the tang of the cultured dairy with the texture of ice cream. But somewhere along the line, frozen yogurts became a low-fat version of soft serve, which is actually pretty low-fat to begin with. From a taste standpoint, these frozen yogurts are just soft-serve ice cream with a little tang, and are very light in texture and eaten the moment it’s extruded from the ice cream machine. From a culinary standpoint, they are lean bases made with a touch of yogurt, and texturally are dependent on a soft-serve machine, just like frozen custard.
AVC: I’d never heard of Philadelphia-style ice cream before reading about it in your book. What is it?
DC: Philadelphia-style ice cream is ice cream made without eggs. The style is so prevalent in America we only know it as ice cream.
AVC: Speaking of Philadelphia, cream cheese plays a bigger role in ice cream than I thought. Why is it important?
DC: Cream cheese is an optional ingredient that has a very concentrated source of milk proteins. When added to ice cream, it adds solid matter, which replaces ice, making it a denser, chewier ice cream in a very flavorful way. The proteins can help bind some of the water in the ice cream as well. But cream cheeses also often have stabilizers in them, which when added to your ice cream can improve the texture as well.
AVC: Is it possible to make ice cream without hand cranks or ice cream makers? What’s the simplest way to approximate ice cream at home if I don’t have all that equipment?
DC: I can’t advocate for making ice cream at home without an ice cream maker. It’s not “all that equipment”—it’s one simple machine that creates a completely unique texture unlike anything you can approximate. The cost is lower than almost every other kitchen appliance one may have in their kitchen, so don’t monkey around with hacks! They will always taste like hacks.
If you want to make ice cream, buy an ice cream maker. Craigslist is a great place to find the ice cream makers people are abandoning from their own ice cream adventures, if you’re worried about cost. Otherwise Amazon will have one at your door in a matter of days, and you can set aside half-baked no-machine “ice creams” and dig into the good stuff. But I will say that all the ice cream bases in the book would freeze well as popsicles if you pour them into molds. You could also dip the ice cream pops into melted chocolate chunks from the add-in section, and it will harden around them like magic shell.