www.re-science.org.au
Sugar Science
The average Australian consumes around
45kg of sugar every year. Sugar is delicious
and can provide us with large amounts of
energy.
Table sugar is a simple carbohydrate with
the formula C12H22O11 (12 carbon atoms, 22 Hydrogen atoms and 11
oxygen atoms) and is called sucrose. It is a disaccharide which means it
is made up of two smaller sugars joined together. These are glucose
and fructose.
Dry sugar, when looked at closely comes in little cube-like shapes.
These are sugar crystals, an orderly arrangements of sucrose
molecules. To create shiny, glassy lollies the crystallisation of the
sucrose molecules must be changed.
Creating Luscious Lollies:
Rock candy (like that found at the Suga Store) is made by heating sugar
syrup until it is highly concentrated and carefully controlling its cool
down to room temperature.
Sugar syrup is made by mixing sugar and water together and heating
until the sugar dissolves. As water evaporates the syrup becomes
more concentrated. The more concentrated the syrup, the higher the
boiling point of the solution and the harder the final candy.
www.re-science.org.au
The cooling of the sugar syrup is carefully controlled to get the right
consistency. Sugar solidifies as it cools. The final appearance and
texture of the candy is determined by the way the sugar solidifies. To
get the glassy appearance of rock candy crystallisation needs to be
prevented.
Without crystallisation lollies form with a shiny, glassy appearance. By
pouring the syrup onto a cold surface, rapidly cooling allows no time
for sugar crystals to form.
Sugar crystallisation can be prevented by adding an acid like lemon
juice. The acid breaks sucrose down into fructose and glucose
preventing sucrose crystallisation (This is called inverting the sugar).
Fatty ingredients like butter also interfere with crystallisation.