What is Semifreddo?
Not all frozen desserts are created equally, as I have learned in my years as a pastry chef. Ice cream and gelato are both made with a custard base containing dairy and eggs that is agitated while freezing to incorporate air, while sorbets are typically made with a fruit purée base that goes through the same churning process.
To get even more technical, frozen desserts differ on the amount of air integrated into the base as it is being churned. Ice cream, with its higher air content, will be much lighter and melt faster on your palate. Since gelato contains less air, the mouthfeel will be very creamy and the flavor will be more concentrated. If you were to melt a cup of gelato and a cup of ice cream (although I don’t know why you would), there would be less melted ice cream than gelato. Sorbets are unique because they do not contain eggs or dairy. Incorporating air into sorbet gives it a lighter texture that differentiates it from a Popsicle.
Luckily for the cook who doesn’t want to deal with the churning process, there is another option: Still-frozen desserts that do not have to be made in an ice cream maker. Semifreddo, meaning “half cold” in Italian, is my favorite example. This frozen dessert contains dairy and eggs, as in ice cream or gelato, and while the semifreddo has a similar texture, the difference is in the process of aeration. Instead of chilling a spinning custard base, semifreddo gets air bubbles whipped into it and then is frozen stationary. To make a semifreddo, air is whipped into heavy cream, then another foam is made by beating air into an egg and cooked sugar mixture. After these mixtures are folded together, this airy amalgamation is placed in the freezer to set. Once frozen, the semifreddo has an ice-cold mousse like texture with a smooth creamy consistency.