Jappy,
I normally read this side of the column but don't participate as you guys are pros, however, I can answer your questions as I've made both many times.
First, ice cream is exactly what it says it is: ice CREAM which the dominant ingredient being cream. Normally, more air is infused in the process to make if lighter. It is much heavier than gelato in taste and weight because of the density of the cream.
With that being said, gelato has a base, in Italy, of 100% milk and no cream at all. We add a small amount of cream here in the USA as we don't have access to the high butterfat content milk they have in Europe. It does make it lower in fat than ice cream and a flavor & texture that is like nothing else in my opinion.
Your basic recipe that you are using is pretty close if you are making a basic non-fruit flavor such as vanilla, amoretti, chocolate, pistachio, hazelnut, etc. as the acids in the fruit will affect your "custard". To give you an idea of how gelato started, a basic Italian pastry filling was made and was then chilled but it was overchilled and the formation of this new dessert started. As most pastry creams are similar in recipe to what you have above, you have the base for gelato. The flavor change by the infusion of whatever flavor you want to add for your basic 'custard' or 'cream'.
When making one with fruit flavors, you follow a different recipe using sugar, milk and a small dose of cream with a dash of lemon juice to enhance the flavor of the fruit. As the fruit has acid, the addition of the egg yolk and the cooking will break down the custard so it's why the fruit is a non-custard base, more like an ice milk.
I hope I answered some questions for you and thanks for letting me contribute here.
Doug  |