Smooth ice cream comes from really small, fine-grained crystals. So what happens if you cool ice cream so quickly that the crystals are nanosized? You get super-smooth nano ice cream!
The Museum of Life and Science in Durham, NC made Nano Ice Cream for NanoDays and will be making it throughout the month of July. Brad Herring agreed to share his recipe and tips with all of you to celebrate the beginning of summer (he's also working on adding the program to the catalog, check back periodically for the full description). If you're in the Durham area, they'll be making ice cream at MLS Wednesday through Saturdays July 8 through August 1, 2009, check out their website for more information.
Really important: Liquid Nitrogen is no joke. The presenter should have on goggles and heavy gloves while using the LN, and no one in the front row should have open-toed shoes.
Nano Ice Cream
Materials for 20 people or ½ gallon
- 1 quart half and half
- 1 pint of heavy cream
- 1 cup sugar
- 8 T of vanilla
- 1 liter of Liquid Nitrogen
- Metal mixing bowl
- Wooden spoon
- Ice cream scoop
- Heavy gloves
- Spoons, napkins, small cups for serving
Brad opens by talking about how tiny crystals make ice cream smooth, freezer-burned ice cream, how we normally make homemade ice cream using ice and salt to cool the liquid.
He then talks about what liquid nitrogen is, how it's made by compressing the gas and then letting it expand and cool, and how very cold it is (so cold that it's dangerous).
Finally, he talks about how adding liquid nitrogen to the ice cream ingredients cools the liquid so quickly that the many tiny little crystals don't have a chance to get very large. In fact, they're nano-sized, which is why we call this "nano" ice cream.
Then he pours some of the LN into the bowl with the cream, milk, and sugar, stirring and adding LN until finished (be sure to close the LN container promptly). And then everyone has ice cream.*
Brad's longer talking points are attached here; keep your eyes out for the full program up on the catalog.
* Ice Cream Sundae Bonus If you want to make a nano ice cream sundae, Dragonfly TV developed a self-assembled ice cream toppings activity for their Dragonfly TV Nano episode on Self Assembly. You can watch the episode here and download the activity guide here.