This summertime treat has been enjoyed for centuries. Get a taste of its manufacturing history, starting from the time Romans collected ice from mountaintops:
There's no better way to cool off during the dog days of summer than with a frosty serving of ice cream. Did you know that this confection traces its origins over two thousand years ago? The process of making ice cream has undergone several changes since.
Emperor Nero was known for his love of iced delicacies of fruit and nectar, but the Roman climate yielded no freezing temperatures to make them. Around 62 A.D., he issued slaves to climb the Apennines Mountains to amass snow and ice. In the 1200s, Marco Polo returned from China with ice cream-like recipes. The love of all things iced traveled from Italy to France when Catherine de Medici married Henry III in 1533. Café Procope in Paris, established in 1660, was perhaps the first ice cream manufacturer and distributor. Even then, commercial ventures in ice cream involved gathering ice from lakes in winter, storing it in holes dug in the ground, and covering it with straw.
Luckily, advances in the sciences aided ice cream production, beginning with using salt to alter ice cream's freezing point. Later, August Gaulin of France created smoother ice cream texture by homogenization, using heating methods to emulsify the mixture's fat content in order to make it uniform in consistency. Meanwhile, some manufacturers tried mixing liquid gasses such as nitrogen into ice cream mixtures to surprising success. Inventions such as the hand-cranked ice cream maker, patented by Nancy Johnson in 1843, allowed people to make small quantities of ice cream in their home fairly easily. In 1851, Jacob Fussel erected the first ice cream plant in Baltimore.
What truly revolutionized ice cream making was the introduction of refrigeration. In the 1870s, Carl von Linde of Germany invented the mechanical refrigerator. The batch freezer and the continuous freezer, used in different methods of making ice cream, were invented in Canton, OH and Louisville, KY, respectively.
The ice cream we eat today is typically processed starting with a mixture that contains 55-64% water from milk and 10-16% milk fat. Serum solids, or the protein component of milk, make up 9-12%, and another 12-16% is sucrose or glucose sweeteners, which may include liquid flavors. To stabilize the mixture, 0.2-0.5% of an emulsifying agent is added.
The stirred mixture heads to the pasteurizer, where it is heated approximately 25 seconds at 175 degrees F. Next, in the homogenizer, over a ton of pressure per square inch is applied to the milk fat bubbles, forcing them to separate and form smaller particles for silky ice cream.
After cooling to about 40 degrees F, freezing follows, either continuously or in a batch. In the first freezing method, a machine constantly streams the mixture through a freezer, whereas in the second method, a set quantity freezes at once. At this time, fruit or nuts are added, while "dashers", or spinning blade, mixes them in.
More importantly, the "overrun" or dashing period, aerates the mixture, which makes the difference between melt-in-your-mouth ice cream and a block of ice. The amount of air fluffed into the mixture is so crucial that all states impose a weight minimum of 4.5 pounds per gallon. Less expensive varieties of ice cream contain up to 50% air, while gourmet ice creams are known to contain as little as possible. A research team including Margaret Thatcher invented soft ice cream, or soft serve. They found a way to double the air in the mixture, producing a different texture.
At last, the aerated mixture is poured into cartons of various sizes. The roaring 20's introduced originality to this step, such as inserting sticks or molding ice cream into bars or other shapes. After hardening in a sub-zero chamber, the ice cream is distributed to stores around the country.
History of Ice Cream
International Dairy Foods Association www.idfa.org/facts/icmonth/page7.cfm