Ice Cream Science

Ice cream is basically frozen foam. It is typically created from a mixture of cream, eggs, sugar and natural or artificial flavors.

Ice cream is basically frozen foam. It is typically created from a mixture of cream, eggs, sugar and natural or artificial flavors. Whipping or beating that mixture traps air bubbles and turns the blend into a tasty foam which is then frozen to create the final product. However, people were making and eating ice cream long before we had refrigeration. So how did they freeze ice cream and have it stay frozen so that people can enjoy the frozen creamy goodness?

Well, before today’s refrigerators people used ice and cold storage in boxes and cellars to store food that needed to stay cold. It was far from perfect, depending on the location and corresponding climate. However, people were more likely to be getting fresh food from their own land or at least from the general area, so long term frozen storage was not a huge priority. For some time before refrigeration people had ice boxes, which would keep items cold using the ice they could have delivered to their homes or business. It was also this ice that some people could utilize in making ice cream.

Water freezes at 32 degrees Fahrenheit, or 0 degrees Celsius. By adding salt to ice you can melt the ice, but the result is a liquid that is much colder than the original ice, going down to negative 26 degrees Fahrenheit, or negative 32 degrees Celsius. To make ice cream, you can whip or beat the ingredients in a bowl and rest that bowl on top of another bowl which you have filled with ice and salted water. If you continue stirring the cream mixture while it rests on top of the colder bowl, the mixture will eventually freeze into a solid, tasty treat.

Now what makes ice cream such a tasty treat? Milk or cream, the foundation for ice cream, contain fat. Each kind of base milk product has a different fat content, and the higher the fat content the richer and smoother the ice cream will be. Sometimes a recipe will call for adding milk powder to the mixture as it is being mixed, in order to trap more air which will make the final product creamier. The air bubbles make the ice cream feel less cold and fluffier. Ice cream can contain up to half its volume in air alone. Sugar is added to the mixture for flavor, meaning sweetness and enhancing the flavor or fruit or other ingredients, but it also makes ice cream softer.

While fans like myself are just happy to have a supply of ice cream, it is always good to know how what you put in your body is made. Next time you eat ice cream that has been bought from the store, read the ingredient list. You might be surprised at what you see. While the ingredients in the paragraph above are all that is needed to create ice cream, many manufacturers of this cold treat add stabilizers and emulsifiers, not to mention artificial flavors, to create the ice cream you can buy to bring home.

Stabilizers make ice cream firmer, stopping ice crystals from forming in the ice cream which would result in a product that is not as smooth and creamy. Commercial ice creams typically use carrageenan, an extract of red seaweed, or sodium alginate, an extract of brown kelp, to act as stabilizers.

Emulsifiers stop the fat found in the dairy based ingredients from separating from the water based ingredients. In homemade ice cream, eggs are most often used as the emulsifier, while commercially produced ice cream often contains chemicals like polysorbates, diglycerides, and monoglycerides to do the job. You can still find ice creams that contain only ingredients that you might recognize, are all natural, or you might be able to pronounce. However, it might take some serious label reading, research, and patience. Making your own ice cream can be a time consuming process, unless you have an ice cream maker, but knowing exactly what you are eating can be a great motivator.

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One Response to “Ice Cream Science”
  1. realityspeaks Says...

    On January 24, 2012 at 8:33 am

    Excellent information.

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