Gelato recipes usually include more egg yolks, more milk and less cream. Technically, the difference between ice cream and gelato comes down to the amount of fat and air. Ice cream tends to have more of each: It contains at least 8 percent butterfat. Ice cream makers then aerate the mixture as it freezes, adding 10 to 25 percent volume to the mix. Gelato typically begins as a custard base of eggs and milk or cream. But these days, many gelaterias use stabilizers to mimic that custardy texture. Gelato contains anywhere from 3 to 10 percent butterfat and very little air, making it denser.