Scripture: Genesis 25-26
- Students will review the story of Jacob and Esau.
- Students will learn Jacob convinced Esau to give him his birthright by giving him some stew.
- Students will learn under what conditions food will be safe to eat for a longer period of time.
- Students will participate in an activity allowing them to discover what types of conditions keep food safe to eat.
Guiding Question: Under what conditions does food become unsafe to eat?
Materials: bread, fruits or vegetables, plastic baggies, refrigerator, freezer or cooler with ice continually replaced as it melts, dehydrator (or other method of drying fruits and vegetables – oven on very low temp, etc.)
Procedure: Review the story of Jacob and Esau and the stew exchanged for the birthright. Explain to the students that in Bible times there was no electricity. Food was often eaten the same day it was killed or cooked. There were also some ways of preserving food for longer periods of time. Ask students to predict what types of things would keep breads, fruits and vegetables safe to eat for the longest period of time. Your discussion should include cooking, refrigerating, freezing and drying. Some students may also be aware of canning and preserving with salt.
Divide students into small groups. Have them divide the bread, fruits and vegetables into several environments. Consider leaving some out in the open air, some in sealed baggies left in the open air. some left in the open air in a refrigerator and/or freezer, some in baggies in a freezer, some in a baggie in the sun and some in the dehydrator you have chosen to use. Have students notice the appearance of the items and record their observations. Have students continue to check the various samples daily and record their observations (Note:The dehydrator may only take several hours depending on the instructions.) Do not allow students to eat any of the samples. Remind them many food borne illnesses and germs cannot be seen without a microscope, but can still make you ill. After several days, ask students to draw conclusions from what they have observed. If you have the resources, have the samples tested for germs and other contaminants. Do the official findings change your conclusions? Students may also want to consult food safety charts to see if what they observed is what is suggested by authorities. (Note: The humidity in your room will change the results. A very dry environment may tend to dry things naturally, while a humid environment may encourage rapid mold growth.
- Can the cleanliness of the person handling the food or the environment where the food is handled, alter the results from the first experiment?
Supplemental Activity: Have more advanced students repeat the experiment. This time before placing items in the various environments, have some touched by someone with food service gloves on while other samples are handled by someone who hasn’t washed their hands in some time or placed directly on unclean surfaces like floors or countertops. Record the results as before. Did items exposed to unclean hands and surfaces change more rapidly than those kept sanitary? Have students share their results with the class and the conclusions they drew from their observations.