Question: What do commercial bakeries do to lard to introduce air bubbles?
About the article "Cake", section "Cake decorating".

Candidate passages:
 decorating.
A finished cake is often enhanced by covering it with icing, or frosting, and toppings such as sprinkles, which are also known as "jimmies" in certain parts of the United States and "hundreds and thousands" in the United Kingdom.
Frosting is usually made from powdered (icing) sugar, sometimes a fat of some sort, milk or cream, and often flavorings such as vanilla extract or cocoa powder.
Some decorators use a rolled fondant icing.
Commercial bakeries tend to use lard for the fat, and often whip the lard to introduce air bubbles.
This makes the icing light and spreadable.
Home bakers either use lard, butter, margarine or some combination thereof.
Sprinkles are small firm pieces of sugar and oils that are colored with food coloring.
In the late 20th century, new cake decorating products became available to the public.
These include several specialized sprinkles and even methods to print pictures and transfer the image onto a cake.
Special tools are needed for more complex cake decorating, such as piping bags or syringes, and various piping tips.
To use a piping bag or syringe, a piping tip is attached to the bag or syringe using a coupler.
The bag or syringe is partially filled with icing which is sometimes colored.
Using different piping tips and various techniques, a cake decorator can make many different designs.
Basic decorating tips include open star, closed star, basketweave, round, drop flower, leaf, multi, petal, and specialty tips.
Royal icing, marzipan (or a less sweet version, known as almond paste), fondant icing(also known as sugarpaste) and buttercream are used as covering icings and to create decorations.
Floral sugarcraft or wired sugar flowers are an important part of cake decoration.
Cakes for special occasions, such as wedding cakes, are traditionally rich fruit cakes or occasionally Madeira cakes, that are covered with marzipan and iced using royal icing or sugar-paste.
They are finished with piped borders (made with royal icing) and adorned with a piped message, wired sugar flowers, hand-formed fondant flowers, marzipan fruit, piped flowers, or crystallized fruits or flowers such as grapes or violets.
Zubbles is a commercial name for colored soap bubbles.
Zubbles claim to fame is that they are the first colored soap bubbles that do not leave stains.
Instead they fade away with exposure to air, pressure, and water.
"Popular Science" named Zubbles the "Innovation of the Year" for 2005.
"Reader's Digest" agreed, saying they were one of the "Best Innovations" of the year in 2006. 
Attack of the 50-Foot Eyesores.
Homer goes to Lard Lad Donuts to get a "colossal doughnut."
Upon realizing that the colossal doughnut is the name of the doughnut that Lard Lad holds and colossal doughnuts that size do not exist, he denounces the store and vows to get a colossal (sized) doughnut.
That night, he steals the giant doughnut from the Lard Lad statue in front of the store.
In the midst of a freak storm, Lard Lad and other giant advertising statues come to life to terrorize Springfield.
Homer eventually returns the donut to Lard Lad, but that does not stop Lard Lad and his friends from causing destruction.
Lisa goes to the ad agency that created those advertising characters, and an executive suggests the citizens stop paying attention to the monsters as they are advertising gimmicks, and attention is what keeps them motivated.
He suggests a jingle will help distract people from watching the monsters.
Lisa and Paul Anka later perform a catchy song and the citizens of Springfield stop looking at the monsters, who lose their powers and become lifeless, except for Lard Lad, who manages to tempt Homer into looking into his donut, stating that it now has sprinkles.
Homer falls for it, but Bart and Lisa pull him away from it, threatening to poke out Homer's eyes if he does not comply, much to Homer's anger.
This causes Lard Lad to lose his power and become lifeless. 
The Continental Baking Company was one of the first bakeries to introduce fortified bread.
It was the maker of the Twinkie and Wonder bread.
Through a series of acquisitions and mergers it became part of Interstate Bakeries Corporation. 
Lard is pig fat.
Lard may also refer to:  Lard (band), a U.S. musical band  Lard (surname)  Lard, Iran (disambiguation), villages in Iran  Allen Lard (1866–?
), an American golfer  Keith Lard, a fictional character in "That Peter Kay Thing" television series  Rebecca Hammond Lard (1772–1855), an American poet  Marc Riley (b.
1961), a British musician formerly known by the pseudonym Lard