Now We’re Cookin!
Lesson Overview
Goals
- Describe why compost heats up during the process
- Identify how heat is lost during the process
Outcomes
Teaching Primer
Those bacteria are on fire! En fuego!
Well, not literally, but as bacteria break down organic material in the compost bin heat is created as a byproduct of the process. When the compost reaches 113 degrees, the thermophilic phase begins and decomposition accelerates as the temperature climbs, sometimes as high as 160 degrees.
During the thermophilic phase it’s important to keep the temperature up so that the bacteria can do their work. But if it gets too hot the helpful bacteria will begin to die off and the composting process will slow or stall altogether. There are techniques to manage the process so that you can keep your compost pile in the good range and maximize the effort of the microorganisms.
Knowing how to raise and lower the temperature will keep your bacteria happy and help to yield the best end product. This lesson will help you do just that.
Teach the Teacher
- Compost Physics
- Why Compost Heats Up
- Compost Log Triggers
- Permaculture, homesteading, and compost-powered heating in the Vermont hills (VIDEO)
Tools & Materials
- Earth Cube or com-posting pile
- Composting thermometer
- Paper and pencil
Vocabulary
- Thermophilic
- Conduction
- Convection
- Radiation
Method
Introduction (10 minutes)
Begin the lesson by reviewing the importance of maintaining a good temperature in your compost bin. Describe the optimal range, how heat is lost, and ways to maintain the temperature.
Activity (20 minutes)
Open the access port of the Earth Cube and have the Students take turns getting temperature readings using their hands to feel heat coming off the pile. Then have them use a compost thermometer to get an accurate reading. Is it in range? Record the readings and establish a final temperature reading based on an average and record that in the Compost Journal.
Discussion (10 minutes)
Is our compost in the optimal range? If not, what should we do to raise or lower it to achieve the optimal temperature? Perform the appropriate actions to adjust the temperature as needed.
Assessment (5 minutes)
Use the following questions to assess the Students before and after the lesson. Tally the responses of the group in the Assessment Tracking Log for comparison:
- By a show of hands, how many of you can tell me the optimal temperature for our Earth Cube compost?
- Now that you know the optimal temperature for the compost in the Earth Cube, how many of you think you could measure it effectively?
Related Lessons
Give the Intermediate or Advanced lessons a try now that you’ve completed the Beginner Lesson!
This lesson, and all other lessons on this website, are intended for use by teachers in the classroom. These lessons are protected by US and International copyright laws. Reproduction or distribution of lesson content, supporting materials, or digital creative is prohibited with written permission from Modern Steader LLC.