ice cream

Caramel nut ice cream

Ice is the name given to any one of the 15 known crystalline solid phases of water. It can appear transparent or an opaque bluish-white color depending on the presence of impurities such as air. The most common phase transition to ice occurs when liquid water is cooled below 0 °C (273.15 K, 32 °F) at standard atmospheric pressure. It can also deposit from a vapor with no intervening liquid phase, such as in the formation of frost.

ice cream is a frozen food (dessert) made with a combination of milk products (usually cream combined with fresh condensed or dry milk), a sweetening agent (sugar, honey, corn syrup or artificial sweetener) and sometimes solid additions such as pieces of chocolate, nuts, fruit and so on. According to FDA regulations, ice creams with solid additions must contain a minimum of 8 percent milk fat, while plain ice creams must have at least 10 percent milk fat.

  • Ice cream is thought to have originated in the mountains of ancient China, with snow probably used as the base.


batch ice cream freezer




  • Yakhchāl (“ice pit”) is an ancient type of evaporative cooler. Above ground, the structure had a domed shape, but had a subterranean storage space; it was often used to store ice, but sometimes was used to store food as well. The subterranean space coupled with the thick heat-resistant construction material insulated the storage space year round. These structures were mainly built and used in Persia. Many that were built hundreds of years ago remain standing

What’s the problem?
Engineering Ice Cream (video 11:31) – Visit two ice cream shops with two very different processes for making delicious ice cream.

  • Ask – What are the main characteristics of really good ice cream?
  • Imagine – What are some of the ways to achieve the desirable characteristics?
  • Design, Build – How are the machines used in the ice cream making process?
  • Improve – How are machines replacing the steps in handmade ice cream?

That’s engineering

  • phase – a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i.e. density, crystal structure, index of refraction, and so forth).
  • solid – one of the four fundamental states of matter (the others being liquid, gas, and plasma). It is characterized by structural rigidity and resistance to changes of shape or volume. Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a gas does.

Engineering ideas

  • freezing point, crystalline, solid, liquid, vapor, frost, sublimate, freeze, phase, transition, rigidity, shape, volume

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