Pucker Up!

 The Science and Business of a Lemonade Stand

This Friday on Arizona Midday I'll be talking about the Science and Business of a Lemonade Stand. Creating a delicious lemonade is a great lesson in acids and bases. The citric acid that comes from lemons is pucker-ific! In order to balance the acidity of lemon juice, a good "lemonologist" must be able to create a formula that offers just the right satisfaction for the palate of various lemonade connoisseurs. To counteract the bitterness of lemon juice, sugar is added to water. Lemons are acidic externally, but alkaline (base) internally. Although sugar has a sweet flavor, it is an acid producer. Due to the high acidic content in lemonade, as tasty and refreshing as lemonade can be it is best to be consumed in moderation.  Other ingredients that "lemonologists" may choose to add to their formula for flavor include, mint, cinnamon and other various spices. During my segment I will also share the science of other refreshing lemon products such as lemon bars, lemon pixi-sticks and lemon bath bombs.


Testing for Acids and Bases
One experiment that I will be sharing includes testing solutions for acids and bases. You can try the following in your own kitchen.

Materials:
1/2 red cabbage
water
pan and stove
strainer
spoon or craft stick
clear cups (9-12 oz.)
sugar
baking soda
citric acid
vinegar
borax
lemon juice

Procedure:

• Cut cabbage into 1" strips and boil it in water until the water turns a bluish/purple. Let cool
• Stain the cabbage from the water, collecting the cabbage water in a separate bowl or large cup. 
• Pour 1 tsp. of sugar into a clear cup and add 4 oz. of water and stir to dissolve the sugar.
• Repeat to make all other solutions (baking soda, vinegar, borax etc...)
• Add 4 TBS of cabbage water to each solution and record any change that you observe.

Red cabbage contains a natural indicator that changes color due to the acidity of a solution. 

 Neutral solutions will create a purplish color.
Alkaline Solutions (base) will appear greenish-yellow.
Acidic Solutions (acid) will react to the indicator solution producing a red to pink color.


Below are pictures from our SciPreneur Scottsdale camp. Students not only worked to create the best lemonade formulas, but they also did some kitchen science while creating lemon bars. We compared two recipes. One called for all-natural ingredients, while the other was a pre-made lemon pie filler.  All though are preservative-free (homemade) lemon bar filling was natural, it was still highly acidic. That being said, it looked 10x better than the can of pie filling that we opened. And when we read the label, there were lots of ingredients that we couldn't even pronounce!