The delicious dessert of chilled milk or cream has developed into many varieties, in many cultures, over time. There is a great deal of overlap of ingredients among foods that take different names, for example ice cream and gelato. There is no French Academy of Frozen Desserts (as far as I know) whose job it is tell us what is and isn’t ice cream etc. Today, the word is used to cover desserts made with a whole range of ingredients. I bring this up to lead you to the most important point of this post, which is: Don’t get hung up on names and categories. They simply are not important to the fun of making ice cream at home. Having said that, it is interesting to review the various styles of ice cream if for no other reason than to understand a common language even if we know that it is an inexact one.
The Dairy-Egg Ice Cream Matrix
Boy that sounds impressive. Maybe I can get a grant to explore this further. Ice creams can be divided into four groups that result from the intersection of the answers to two questions. Does a recipe contain dairy products or not and does it contain eggs or not? These groups pretty much encompasses the entire universe of frozen desserts. Is knowing this profoundly useful in some way? Heck no, I just had fun thinking of it.
American, Philadelphia Style, or Standard Ice Cream
There are probably even more names for this style. This is ice cream at its most basic, made of milk, cream, sugar and added flavoring. It’s flavor is primarily about the simple direct taste and richness of cow’s milk. A pint of classic Philadelphia ice cream, from which the whole universe of ice creams expands, could be made up of 1/2 cup of whole milk, 1 1/2 cup of heavy cream, 6 tablespoons of table sugar, and 1 teaspoon of vanilla extract. For the sake of purity you can even leave out the vanilla. Mix to fully incorporate the sugar, until smooth. Freeze as quickly as you can while agitating in some way (Here is a method.). If no additional ingredients have been added to prevent large ice crystal formation, standard ice cream is best eaten right out of the ice cream maker, with only a short period of hardening in the freezer.
Philadelphia style is easier to make than egg custard based ice cream because it is heated only enough to effectively incorporate the sugar. Some recipes call for additional heating, even boiling, in order to release some water from a mix or to thicken one containing corn starch. This is done to improve the resulting texture of the ice cream. I urge you try making Jeni Bauer’s version to experience what a huge difference a truly outstanding texture can make to an ice cream.
French Style, Custard, Frozen Custard, Gelato
These dairy based ice creams contain another primary ingredient, egg yolks. In these ice creams it not uncommon to see 10, 12, or even more egg yolks per quart/liter. In addition to adding a gloss to ice cream, egg yolks help keep ice crystals small and texture smooth. They also add a deep richness, complexity and egginess to the taste of ice creams made with them. That has both a benefit and a cost as the egginess can compete with the intended flavor of the ice cream. For example, strawberry ice cream can become strawberry – egg ice cream. However, when the flavors are complimentary, as in olive oil gelato, it is mind blowing. As the word custard implies ice cream containing egg yolks are almost always cooked to form a thickened custard before freezing. This is done for reasons of both health and flavor.
Gelato is an Italian word for frozen. It often contains more milk, and less or no cream, than Philadelphia style ice cream. Gelato may contain a great number of egg yolks but this is not always the case. The only consistent factor I could find is that when made commercially it is made using a churning process that incorporates as little extra air as possible. True gelato is more dense than standard ice cream. There is a myth that gelato is lower fat or somehow healthier than ice cream. Though this is not the case, I encourage you to tell yourself this while on vacation in Italy.
Non-Dairy Ice Creams
Frozen desserts approximating ice cream, and in there own ways capable of being just enticing, can be based on a number of non-dairy liquids. Soy milk, almond milk, coconut milk, the milk of other animals such as goat, vegetable and fruit juices; these cover some but probably not all possibilities. For that matter, delicious frozen treats can be based simply on ice such as granita or sorbet. Except for those that embrace ice wholeheartedly (under- explored and under-appreciated I’m afraid), many non-dairy ice cream recipes are as much about ingredients whose purpose it is to approximate the smoothness and mouth-feel of dairy ice creams as they are about flavor. Whether you are obsessed with smoothness or not there is great room for experimentation in making dairy-free ice creams at home. In addition to offering a whole alternate play-space of delicious foods, they have the potential to be not just less unhealthy than traditional ice creams but actually healthful. Read this as an example.
I think you can make the case that the rise of frozen yogurt began as a marketing scam whose purpose was to dupe people into thinking that it was healthier than ice cream. It is not. Depending on the recipe it may or may not be low fat but is often high in sugar; which depending on the person and consumption level, can be very unhealthy. With time people began consuming it simply to enjoy the inherent taste of yogurt, primarily that tanginess that comes from being fermented. Yogurt and other fermented liquids and foods are best thought of as one more potential flavor ingredient with their own unique attributes.