Thanksgiving is a time for family, feasting, and togetherness. Another great thing is that many schools give a day or two off before and after, so most people have plenty of time to relax and sleep off the feast. However, just because school is out doesn’t mean that you and your family can’t keep learning during Thanksgiving. From bending turkey bones to cranberry chemistry, you can do plenty of science demonstrations with food. Here are three fun science projects that you can do this Thanksgiving.
1. Cranberry Chemistry
Cranberries may be the official fruit of Thanksgiving. Whether it is cranberry sauce on a turkey, or a delicious cranberry pie, the berry has become a staple on most tables during the holiday. Beyond being a popular treat, cranberries contain anthocyanins. Anthocyanins are pigments that change color depending on if they are reacting with an acid or a base. Because cranberries are naturally acidic (it is part of the reason they have a somewhat tart taste) the anthocyanin reacts with the acid to make the berries red. However, if you change the acidity, you can change the color too.
For this project, you will need a clear glass, baking soda, cranberry juice, and lemon juice. Then just follow the steps below:
- Pour one cup of cranberry juice into the glass.
- Add a tablespoon of baking soda and observe the reaction. Things to look out for are bubbling, noises, and changes in how the liquid looks.
- Wait 2 minutes, and observe if any changes occur.
- Add two tablespoons of lemon juice, and again, pay attention to see if there is any reaction.
Baking soda is a base, so it should first foam up a bit when it contacts the acidic juice, and then react with the anthocyanin to turn the cranberry juice from red into a darker purple or blue color. When you add the lemon juice, which is acidic, it should neutralize the basic baking soda to again react with the anthocyanin and bring the juice back to a more red color.
To learn more, you can do experiments like testing if the order ingredients are mixed will lead to different effects, or change the amounts of each ingredient you mix. Another thing you could do is try adding baking soda and lemon juice at the same time or use other acids, like vinegar (you’ll need it for the next activity anyway). If you decide to add lemon juice or vinegar with baking soda at the same time, be ready for a foamy mess. It may be best to do this in a bathtub or outside and have a change of clothes on hand for your children to change into after.
2. Bendy Bones
A steaming and scrumptious turkey is an essential part of Thanksgiving in most households. However, no matter how much everyone eats there are usually some bones left over at the end. If you take a couple of the larger bones, for example, the drumsticks, you will notice that they are stiff and won’t bend much. This is because the turkey needs solid bones to support its body. The bones have calcium in them, which helps make them strong (and which is why it is important to drink milk!).
There is a project you can do that should remove the calcium from the bones and completely change their character. Here is how:
- Scrape any meat off of the bones.
- Note some observations about the bone. For example how flexible it is, its color, and if you have a kitchen scale, its weight.
- Fill up a bowl with enough vinegar to completely submerge the bones.
- Place the bones inside of the bowl, covered in vinegar for four days. (To cut down on the smell, cover the vinegar with plastic wrap.)
- Remove the bones from the vinegar and make observations. Compare these to your original notes to figure out how the bone has or has not changed.
Because vinegar is acidic, it should remove calcium in the bone. After soaking for days, the bone should be very flexible and bend easily. This is because the hard calcium is mostly gone, but the softer, more flexible materials in the bone remain. You can try putting different sized bones in vinegar to see if the size of the bone will affect how quickly it will start to bend, soak only a part of the bone vinegar, or try soaking bones in other mild acids, like lemon juice or cola to see what kind of effects this leads to.
3. Re-growing Food From Scraps
When your family is putting together a Thanksgiving meal, they probably end up with lots of vegetable scraps. While the carrot tops, onion peels, and more may make great additions to a compost pile, you can also regrow some of them in your own home. This can be a fun project, a great way to use your food more sustainably, and an easy way to cut down the grocery bill. Here is how:
- When cutting green onions or scallions, leave about 3 inches above the root intact.
- Take the left over roots and place them standing up in a glass.
- Fill the glass with some water, but leave an inch or two of the roots above water.
- Put the glass in a sunny window.
- Change the water every other day.
Within a few days, you should start seeing green shoots coming out from the roots. Once the shoots are long enough, you can use the new growth from the green onions to cook again. Then, you can put the roots back into the glass to regrow. Each time the scallions are put back in, they will probably grow less.
After a number of cycles, they will usually completely stop growing.
To learn more, you can try experimenting to see what will give you the most growth cycles. For example, will adding plant food to the water make the onions grow faster and for more cycles? In the following months you can use new onion roots to see how well they grow after half a week, one week, and two-week cycles of growing and cutting. You could also see if they grow better in a glass with water, or in a small flower pot. There are a huge number of variations you can try to see what the most sustainable way to regrow the green onions are. If you keep good notes, it may even make a great science fair or extra credit project!
Thanksgiving is a great time to bond with your family and to feast on fantastic foods. However, just because it is a vacation doesn’t mean you can’t do some experimentation! From re-growing foods to chemistry with cranberries and bending bones, with the above activities, the whole family can keep learning through the holidays. Perhaps best of all, these Thanksgiving experiments can stretch days, weeks and even months past the end of the holidays. They can be a great activity to keep the family bonding once they get back into the routine of things.