heidi notes: This is a nice, creamy gelato-type base. Infuse it, add stuff, get creative. I wrote this recipe a few years back - I tend to use arrowroot instead of cornstarch as a thickener in recipes that need it (it is usually less-processed than cornstarch). But because I haven't tested arrowroot in this base, I'll give you the cornstarch version. If you use this as a base for liquid nitrogen ice cream, please read up on the safety precautions that must be observed when handling LN2.
4 cups whole organic milk
1 vanilla bean, split
1 cup sugar
3 tablespoons plus 2 teaspoons cornstarch
1 teaspoon vanilla extract
Place three cups of the milk in a saucepan with the vanilla bean over medium-low heat.
Meanwhile, pour the remaining 1 cup milk into a large glass measuring cup. Add the sugar and the cornstarch. Mix well.
When the milk starts to simmer, remove it from the heat and pour in the cornstarch mixture, stirring the whole time. Return the saucepan to medium-low and stir, stir, stir, until things start thickening up, 10 to 12 minutes. It should end up thicker than, say, a runny milkshake, but thinner than a frosty one.
Pour the mixture through a strainer into a mixing bowl, whisk in the vanilla extract, and let it cool on the counter for 20 minutes or so. I like to then chill it in the refrigerator for a few hours or overnight until it is completely chilled.
Now you are ready to place this mixture in a metal-bowl mixer and do the liquid nitrogen thing (see above links and do your safety reading and research first), or you can just freeze this using the manufacturer's instructions on a standard ice-cream maker.
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