Procedure
• At the same time, fill one plastic cup with ice-cold water (from the bowl of ice cubes and water you prepared, being careful to not add any frozen bits of ice) and fill the other cup with very hot tap water. Fill both cups to the top with water.
• Set a timer, or note what time it is, and check on the cups every 10 minutes for the next 45 minutes. When you check on them, make a small line on each cup where the top of the beans are. Write the time next to the mark. How does the bean level in each cup change over time?
• After 45 minutes (or longer), which cup has the higher bean level? What does this tell you about whether cold or hot water is more quickly absorbed by the beans?
• When you are done with this activity, you could discard the beans—or you could include them in a bean-based recipe of your choice, such as black-eyed pea soup!
• Extra: Another way to measure your results in this activity is to weigh the black-eyed peas with a scale. You could use multiple cups and weigh the beans from those cups (after straining out the water) as they are soaked in water for various lengths of time (such as 30 minutes or one hour). How does the mass of the black-eyed peas change over time? Is there an amount of time after which the beans remain roughly the same weight?
• Extra: Try this activity using various types of legumes (legumes include beans, peas and lentils). Do some legumes absorb water faster than others? What does this tell you about how long they might need to be soaked before cooking them?