“Soft Ice Cream” can mean several things.
It can mean ice cream that hasn’t frozen very hard. Anyone who has tried to make ice cream in their home freezer knows that making soft ice cream is not a challenge. The challenge is getting it to go hard when you want it to.
The phrase can also refer to ice cream that has gone soft by being let stand out of the freezer (or when chilling mechanisms have failed.)
Generally, however “soft ice cream” means ice cream that is purposely designed to stay semi-soft so that it can easily be piped out of machines onto cones. This is often also called “soft-serve.” In some parts of the world, it is known as American soft ice cream
Some sources state, incorrectly, that soft ice creams contain the same ingredients as ordinary ice cream. This is wrong: the ingredients chosen are designed to help keep the soft ice cream soft and dispensable. Soft ice creams — even soft ice creams that are kosher, which people mistakenly think of as being “purer” — will contain additives such as sodium citrate and disodium phosphate. These additives reduce the amount by which proteins adhere to each other, which also helps to keep the ice cream softer and moister. The soft-serve ice creams are also whipped to double their air volume, which makes them freeze less solid and dispense more easily.
Machine dispensers will often combine flavours as they come out the nozzle.
Many commercial ice cream cakes are made with soft ice cream, as it is more mouldable, then frozen hard
To make soft ice cream at home (the whipped, dispensable kind, as opposed to the homemade that just never froze, or the carton of ice cream that got forgotten on the counter) you need to buy a machine that turns regular hard ice cream into soft-serve. The machines are inexpensive.
Nutritional values will vary wildly based on the brand and product.
The soft ice cream machine dispenser was invented in America in 1938 (some sources say 1936.) Carvel Ice Cream in America claims to be the first in America to have sold soft ice cream.
Margaret Thatcher worked for J. Lyons Ice Cream in Hammersmith after graduating from Oxford in the 1940s as a chemist. She was on a team that helped developed a method for more air to be whipped into ice cream. This meant that the ice cream wouldn’t freeze as hard.
In North America, the reigning brand name of soft ice cream is Dairy Queen; in the UK and in Australia, it is Mr Whippy.
Ice cream is generally just called ice cream, except when one is talking about soft ice cream: regular ice cream is then described as “hard ice cream” to distinguish it.