Saturday Science: Fizzy Sherbet
When you think of sherbet you may think of that tasty fruity stuff that's kind of like ice cream. If you’re from the United Kingdom, though, it might make you think of something else: a fizzy sour candy that bubbles on your tongue. It’s just as delicious as frozen American sherbet and it’s super-easy to make at home. Best of all, it involves some of the science of chemical reactions to make it fizzy. It’s science candy!
- 1 tsp powdered Sugar
- ½ tsp Citric acid powder (you can get this at most vitamin and supplement stores)
- ¼ tsp Baking soda
- ½ to 1 tsp pre-sweetened Kool-Ade or any other kind of flavored drink crystals
- Sealable plastic baggies
- Measure out all of your ingredients into a plastic baggie. Seal it up nice and tight.
- Mix the ingredients by shaking the baggie. You may want to mush the ingredients around with your fingers, too, to make sure there aren’t any clumps.
- When you have a nice smooth mixture, open up the bag and enjoy your sherbet! Start by dipping your finger in and putting some on your tongue. You don’t want to put too much in your mouth because it’ll fizz up and get way bigger than it was when it went in!
The fizzing foam that the sherbet makes when it touches your tongue is a result of a very simple chemical reaction. You may have seen something similar if you’ve ever mixed baking soda and vinegar. In this case, the chemicals doing the reacting are baking soda and citric acid, which is the kind of acid found in citrus fruits like lemons and limes. It’s what makes them sour.
Vinegar and citric acid are both a type of chemical called an acid. Some acids are very strong and dangerous but some are safe in small amounts and give flavor to foods and candies. Baking soda is a type of chemical called a base. Just like acids, there are very strong and dangerous bases, but there are also a few weak ones that are safe to eat, like baking soda. Acids and bases are opposites of each other and when they mix there is always a chemical reaction, where the atoms that make up the acid and base start recombining into new chemicals. When you mix baking soda with either vinegar or citric acid some of the atoms recombine into carbon dioxide gas, and as the gas escapes the sherbet it makes it fizz and bubble up in your mouth.
Why don’t the baking soda and citric acid do that when you put them in the baggie? The reaction requires moisture, and it gets it from the inside of your mouth.
Once you’ve made sherbet once it can be very tempting to make more. You can try different flavors of drink mix to see which ones you like best. Since the drink mix and the powdered sugar are just there to give the sherbet some flavor, you can try just mixing the citric acid and the baking soda. It will still fizz up in your mouth but it might not taste as good!