Keeping the Harvest
This lesson challenges families to discover how people preserved food long before refrigerators. Through a simple experiment with cucumber and apple slices, learners will explore the science behind drying and salting, understanding how these methods prevent spoilage. The family will set up an experiment and observe changes over several days.
The lesson goal is learners will understand how traditional food preservation methods like drying and salting prevent spoilage by removing water. They will be able to observe, record, and explain the effects of these methods on food over time.
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Learning Guide
Step-by-step guidance. No preparation required.
- 1
Introduction: The Winter Challenge5 Min
- Ask: 'How did families keep food from spoiling all winter, long before refrigerators?'
- Move on when Student has shared at least one idea about how food might have been kept from spoiling.
Photo by Silvia Macedo Decorações on Pexels - 2
Explore & Plan: Our Food Preservation Test8 Min
- Gather cucumber, apple, salt, plates, paper towels, and the experiment log.
- Discuss salting and drying. Ask: 'What do you think salt does to food?' 'What happens when food dries?'
- Explain the control. Ask: 'What do you predict will happen to the salted cucumber, the plain cucumber, and the drying apple?'
- Introduce the experiment log. Explain it's for recording observations each day.
- Move on when Student has made predictions for each food item and understands the setup of the experiment log.
Photo by Stefan Vibes on Pexels - 3
Discussion: The Science of Spoilage6 Min
- Explain spoilage: food going bad because tiny **microorganisms** (like bacteria, mold) grow on it.
- Ask: 'What do all living things, even tiny microorganisms, need to live and grow?' (Water).
- Explain **dehydration** (drying) removes water, and salt pulls water out of food. Ask: 'How does removing water stop microorganisms?'
- Move on when Student can explain in their own words that food spoils due to microorganisms and that drying/salting prevent this by removing water.
- 4
Activity: Setting Up Our Experiment9 Min
- Carefully slice one cucumber into two 1/4-inch rounds and one apple into a 1/4-inch ring.
- Place one cucumber slice on a plate and sprinkle generously with salt. Label it 'Salted Cucumber'.
- Place the other cucumber slice on a separate plate. Label it 'Plain Cucumber'.
- Place the apple ring on a paper towel on a third plate. Label it 'Drying Apple'.
- Have your child observe each sample (look, feel, smell) and record Day 1 notes on their experiment log.
- Move on when All three food samples are prepared and labeled, and Day 1 observations are recorded in the experiment log.
- 5
Summary: The Harvest's Secrets Revealed2 Min
- Remind your child to observe the samples and record changes daily for the next 2-3 days.
- Once completed, review the log together. Ask: 'What surprised you? Which method worked best and why?'
- Move on when Student can describe what they expect to see over the next few days and connect the experiment back to the main question of preserving food for winter.
Photo by Oben Kural on Pexels
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