This Week's Experiment - #220 Sweet Tea

These experiments are from Robert Krampf - The Happy Scientist

This week's experiment idea came to me while I was waiting for our lunch. The proper drink to go with your Memphis Bar-BQ is sweet tea. Now, you may not think that is unusual, but true, Southern sweet tea is a very different drink. The difference is based in the science of chemistry. To experience this, you will need:



2 pans

water

tea bags

sugar



WARNING: For this experiment, you will have to boil water. Be sure to get permission and be safe.



Put two cups of water into each pan. Heat the water until it boils. Add a couple of tea bags to each pan. To one pan, add 2 tablespoons of sugar. After boiling for a few seconds, turn off the heat and let them cool. Once they are both cooled, add two tablespoons of sugar to the unsweetened tea. Be sure to mark the pans, so you can tell which is which. Once the sugar is dissolved, taste each one. You will find that the tea that was sweetened while it was hot is sweeter. Why?



Your first thought might be that more of the sugar dissolves in hot water than in cold. That is why we only used 2 tablespoons of sugar. We want all of it to dissolve, even in the cold tea. With the same amount of sugar in each, they should both taste the same, right? Then, why is one sweeter?



The tea that was sweetened when it was hot now has a different kind of sugar in it. Yes, there are different kinds of sugar. The sugar that we normally use is called sucrose. Sucrose is a sugar that plants make and use to store energy. When you add the sucrose to the hot tea, a process called inversion takes place. The sucrose breaks down into two other sugars, glucose and fructose. This combination, called invert sugar, is about 10% sweeter than the sucrose it was made from. This process of inversion is very useful. Bakers use invert sugar to make confections sweeter. Bees use enzymes to do the same thing when they are making honey.



Now, true Southern sweet tea is SWEET! In addition to inverting the sugar, the hot tea allows you to dissolve more sugar in the tea. This combination is one that may be too sweet if you are not used to it. If you want to try the real thing, use about a cup of sugar for a quart of tea. Chill it until it is very cold and serve it over ice. Then all you need is some Memphis bar-BQ, some cole slaw, baked beans and some banana pudding and you are all set for a feast.