Introduction: (Initial Observation)
Popcorn or popping corn is a type of maize which puffs up when it is heated in oil or by dry heat. Special varieties of corn are grown to give improved popping yield. Some wild types will pop, but the cultivated strain is Zea mays L. subsp. mays (Everta Group), which is a special kind of flint corn. It is a popular snack food all over the world.
In the United States, popcorn is particularly common in movie theaters. It is often served with butter and salt. It is also sometimes flavored with sugar (especially in Europe) or spices. In Sweden it is sometimes served with sugar and vinegar.
Popcorn balls (popped kernels stuck together with a sugary “glue”) are a traditional Halloween treat. Cracker Jack is a popular, commercially produced candy that consists of peanuts mixed in with caramel-covered popcorn.
Information Gathering:
Find out about corn and popcorn. Read books, magazines or ask professionals who might know in order to learn about the factors that may affect the ratio of popped kernels in popcorn.
Following are samples of information that you may find:
Popcorn is not a recent food but has been around for thousands of years. It is created by heating corn kernels which explode outwards once the water inside expands and builds up enough pressure. The great thing about popcorn is that it is a good source of carbohydrates, fibre and protein. Slimmers might also like to take note that it is very low in calories (27 calories per 100g) if eaten plain. Want to know more then read on…
Popcorn recipe
25g popping corn
Oil
3 tbsp / 40g butter
Pinch of salt
Place enough oil into a large heavy based saucepan so that it just covers the bottom. Begin to heat the pan on a medium heat and add the popping corn. Next cover the pan with a tight fitting lid, when the popping starts shake the whole thing vigorously.
Once the popping has stopped remove the saucepan from the heat and allow it to cool for a few minutes, this allows any unpopped kernels time to pop.
Melt the butter in a microwave or pan, then gently pour over the freshly popped corn. Stir the popcorn until it is completely coated in the butter, then add salt to taste.
Question/ Purpose:
What do you want to find out? Write a statement that describes what you want to do. Use your observations and questions to write the statement.
The purpose of this project is to find out:
Which popcorn brand pops faster?
or
Which popcorn brand pops the most?
Identify Variables:
When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other.
For question “Which popcorn brand pops faster?”
The independent variable (also known as manipulated variable) is the brand of popcorn.
The dependent variable (aka responding variable) is the time it takes of popcorn to pop.
For question “Which popcorn brand pops the most?”
The independent variable (also known as manipulated variable) is the brand of popcorn.
The dependent variable (aka responding variable) is the ratio of popped kernels.
Hypothesis:
Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis.
This is a sample hypothesis:
Among the three brands (HotPop, Critic’s choice and Poppers) HotPop pops faster.
Experiment Design:
Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a “control.” A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral “reference point” for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a “controlled experiment.”
Experiment 1: Which popcorn brand pops faster?
Introduction: In preparing popcorn, you heat up the corn kernels in a pot or in a microwave oven. While preparing popcorn you may have noticed that corn kernels do not all pop at the same time. Some pop faster than others. It is possible that some popcorn brands have more of the kernels that pop faster. In this experiment you will compare the popping time among 3 different brands of popcorn.
Safety note: Adult supervision and support is required. You will be working with hot ovens. Let the oven cool off completely between your experiments and before each cleanup. Use of microwave oven is not recommended in this experiment due to a possible risk of causing cancer.
Procedure:
- Get three brands of popcorns.
- Remove 3 kernels of each brand, place them in the center of a 6 x 6 cm aluminum foil (or 3″ x 3″). Add five drops of liquid oil. Three fold the foil and then fold the sides. This will make a temporary small aluminum bag for the seeds. Mark each bag so you will know which bag belongs to which brand.
- Place all bags in an electrical oven.
- Turn on the oven at it’s highest temperature setting and immediately take the time.
- See through the glass window of the oven until the first pocket pops. Immediately record the time and continue your observation until the second foil pops. Record the time again. Continue your observation until the last foil pops and record the time again. (Record time in minutes and seconds past from the time you start the heat. So if you record 5:23 if the sample pops 5 minutes and 23 seconds after you start the heat)
- Repeat this experiment 5 times and record your results in your results table.
- After completion of all five experiments, take an average of the popping time of each brand and record it in the table. Your results table may look like this:
| Popcorn Brand * | Popping time 1 | Popping time 2 | Popping time 3 | Popping time 4 | Popping time 5 | Average Popping time |
| HotPop | ||||||
| Critic’s Choice | ||||||
| Poppers |
* Note that you may test different brands that are available in your neighborhood.
8. Use the average pooping time to draw a conclusion.
Need a control for your experiment?
You can use a different brand or type of popcorn for your control. Every time that you place one bag of popcorn in the microwave for your experiment, you must place another bag of control popcorn beside that. So for every bag of test popcorn you need one bag of control popcorn.
Control can also be another brand of microwave popcorn that you use only as control.
Since always you use the same type of control, the number of popped corns in your controls must remain consistent. If you notice a big change, that might be due to a problem with your microwave device and makes that specific trial invalid. (You need to repeat that).
Many students do not use a control and assume that all experimental popcorns will be tested under identical conditions. Having a control experiment is usually required for higher grades.
Make a graph?
You can use a bar graph to visually present your results. Make one vertical bar for each of the brands you use. The height of the bar will show the average popping time. For example you may use a 75 mm tall bar for a popcorn brand that popped in 75 seconds. Write the brands under or over the bars.
Experiment 2: Which popcorn brand pops the most?
Introduction: In preparing popcorn, you heat up the corn kernels in a pot or in a microwave oven. After preparing popcorn you may have noticed that some corn kernels did not pop at all. Do you know what ratio of the corn kernels did not pop? Is it possible that some popcorn brands have more of the kernels that pop and less of the kernels that do not pop? In this experiment you will compare the popping ratio among 3 different brands of popcorn.
Procedure:
- Get three different brands of microwave popcorn.
- Use the instructions provided with each brand to pop the corn kernels. Stay away from the microwave while it is working.
- When the popcorns are all popped, open each pack and count the number of popped kernels and un-popped kernels. Add them up to calculate the total number of kernels.
- Record your results in a table like this:
Popcorn Brand * Number of popped kernels un-popped kernels Total number of kernels Ratio of popped kernels HotPop Critic’s Choice Poppers
* Note that you may test different brands that are available in your neighborhood.
5. Calculate the the ratio of popped kernels. To do this you must divide the number of popped kernels by the total number of kernels.
6. Report the ratio of popped kernels in each brand and conclude which popcorn brand has the highest ratio of popped kernels.
Materials and Equipment:
- Toaster oven
- Microwave oven
- Aluminum foil
- Three different brand of popcorn
Results of Experiment (Observation):
Experiments are often done in series. A series of experiments can be done by changing one variable a different amount each time. A series of experiments is made up of separate experimental “runs.” During each run you make a measurement of how much the variable affected the system under study. For each run, a different amount of change in the variable is used. This produces a different amount of response in the system. You measure this response, or record data, in a table for this purpose. This is considered “raw data” since it has not been processed or interpreted yet. When raw data gets processed mathematically, for example, it becomes results.
Calculations:
To calculate the total number of kernels you must add the number of popped kernels to the number of un-popped kernels.
To calculate the ratio of un-popped kernels you must divide the number of un-popped kernels by the total number of kernels.
Summary of Results:
Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.
It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.
Conclusion:
Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did.
Related Questions & Answers:
What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.
Possible Errors:
If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.
If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.
