Resources: A small beaker containing milk (full fat or semi-skimmed, but not UHT), a small beaker containing sodium carbonate solution (0.05 mol dm−3 ), a small beaker containing 5% lipase solution, 250 cm3 beakers, to be used as water baths, test tubes, a test tube rack, a marker pen, 10 cm3 plastic syringes, a stirring thermometer, stop clock / stopwatch, phenolphthalein in a dropper bottle, an electric kettle, for heating water, ice, for investigating temperatures below room temperature.
Imagine you are building your own compost heap in their gardens. What type of things would they put in it? What conditions are required for successful decomposition inside their compost heaps?
Answer questions and take part in activities during the presentation. Stop the presentation at the relevant slides: Talk Partners; AfLs; Songs. Take part in the Choral Response Questions activity (see Assessment section) after the Keywords/Rocket Words slide.
Expert Film: This is Alex Semenyuk, who works with the RHS as an Anaerobic Digester Manager at Barfoots. Alex talks about rate of decay.
Career Film: Alex Semenyuk works with the RHS as an Anaerobic Digester Manager at Barfoots.
Investigate the effect of temperature on the rate of decay of fresh milk by measuring pH change.
With their talk partners, the children are to go through the quiz at the end of the presentation and answer the questions.