gelato: is heating required?

[hgregs]

we just got a gelato chef 2500, which came with a recipe book. we just made pistachio from the following recipe:

125g sugar

200g milk

150g cream

1 egg

75g pistachios

2tbls liquer

finely crush nuts w/ sugar, add eggs (whisk everything til thick), cream, milk, liquer, stir, and pour the mixture into the gelato maker bowl. run for 25min.

results were excellent. all recipes in the book are similarly uncooked.

however, looking online for a vanilla bean recipe, and futher searching this site, gelato recipes appear to always have a heating element.

would someone please explain if one way is more or less correct, and why? i understand that cooking will render the raw egg more safe. but i'm thinking there has to be more to it. these uncooked recipes seem too easy (with pleasing results).

greg

 

[grumio]

Yes, if the recipe calls for heating, do it.  Many gelato recipes (most, even) are frozen custards, where you heat the dairy/egg yolk mixture to ~180F/80C both for safety and to thicken the mixture & provide a creamier texture.  The proteins & emulsifiers  in egg yolk help keep ice crystals small, & in ice cream, small ice crystals = smoother texture. 

I'm sure somebody else here can explain it better.