Science Buddies: "Ask an Expert"

We (my 4th grader and me, her mother) are busy conducting the maple syrup experiment for the science fair. After cooking up 4 bottles of varying bottles of pure maple syrup (we started with the dark amber and slowly worked our way to the organic Grade A light amber because of its higher content of sucrose) we are getting exhausted. The main problem of this experiment is, that the ice on the frozen sheet always melts when a hot or warm dollop of syrup is dropped. To prevent the melting of the ice and the subsequent "brown puddle" we placed 1) parchment paper and 2) aluminum foil over the ice to get the frigid temperature but not the water. Well, the parchment paper became moist as well and the aluminum foil might have impacted the crystallization. In any case, we got the best crystals in the pot where we kept stirring while the solution was cooling. (We read that the mechanical shock produced by the stirring causes crystals to form easier.) We also observed some crystals on the black room-temperature cooking sheet after the dollop solidified. Our questions are: 1) How can we get the freezing temperature without the "puddle effect"? Is there a cover that's more suitable than what we used? We also tried merely putting the pan in the freezer but measured that the baking pan was quickly heating up to room temperature after 2 or 3 dollops were placed. 2) We seem to be very successful at crystallizing maple sugar in the hot sauce pan (which is sort of the opposite of what we were expecting). It seems to be a surefire thing that crystals will form in the sauce pan as soon as all the water is evaporated. What's the difference between the crystals that we find in our sauce pan and the ones that are supposed to form on the frozen sheet? Are they supposed to vary in size? Or shape? Currently, we tend to disagree with our hypothesis and state instead that the hot sauce pan produces the best crystals. 3) What kind of data table should we present? It doesn't seem to make sense to measure the size of the crystals (since that simply depends on how big the dollop is or in case of the sauce pan, is not measurable in cm). We also have difficulty with the speed of crystallization since we didn't set a stop-watch for the sauce pan and it also seems to be difficult in general to pick the time when the first crystal appeared. They're sometimes hard to see with the foam and bubbles. Any advice would be greatly appreciated!

Hi Lutetia,

Welcome to Science Buddies! I think you are doing this really great project from the Science Buddies website:

https://www.sciencebuddies.org/science- ... p044.shtml

This is great that you are getting crystals; the most common problem with this project is that no crystals form, however, I can imagine that the melting water from the ice sheet is interfering with obtaining results.

1. Your idea to use parchment paper and aluminum foil was great to try to solve the water dilution problem, I recommend that you use a solid cold surface as a heat sink to do the experiment. Depending on what you have available you could try:

1. Freezing a granite or marble cutting board.
2. Freeze a brick and metal baking sheet
3. Freeze a solid metal object like an block of aluminum
4. Place a metal baking sheet on top of dry ice
5. Maybe a frozen cast iron skillet would work.
6. Ask your daughter to think of something else dry and solid that would stay cold for a while after it is frozen.

One of these options should solve the problem. Please let us what you decide to try and what happens.

2. Theoretically, the crystals that form slowly as the hot sauce pan cools will be larger than the crystals that form quickly on a cold surface. However, results are empirical, depending on your experimental protocol. So you should report the results as you have observed them.

3. The results can be presented in a table and could be based on crystal size (measured in centimeters) or time. Since this is a science project, it’s important to report a measurable result. However, you have had technical difficulties in conducting the experiment, so I would recommend estimating the time for the sauce pan and including the measured time for the cold samples. If you have the time and energy, you could do one more sauce pan experiment and try to measure the actual time.

If you have taken photographs of the crystals, this would be a good addition to the results section of the board.

Your daughter can include the details of the difficulties encountered in doing this project in the discussion section, and write about her observations and how she solved the problems. The discussion should also include the limitations of the data (it was necessary to estimate some times), and some suggestions of what she would do differently if she were to do the experiment again. Science fair judges always appreciate a good discussion section.

I hope this helps. Let us know if you have any other questions.

Donna Hardy