As the quality improves, they will want to be able to replicate or produce it consistently. This will require accurate measurements. The Beauty of this lesson is that it can be used to reach so many objectives. It is most often used as an activity to teach, give practice, or to assess students' knowledge of dealing with variables. It also offers exposure to the experimental process, forms of matter, changing forms of matter and many other science concepts and processes.
Teachers can decide which to recycle.
Doing this activity outside simplifies clean up. I bag 3. I bag and zip it up. I bag and the two shake until ice cream is firm. Cups and spoons are then distributed to students for taste testing and eating.