Yesterday, I did a simple home-made experiment with my children. They always ask me what products can be made from milk. After listing milk-based products, I decided to introduce them making curd by adding acid to warm milk. To separate the curd from the whey liquid I used different filtering materials (papers). My children enjoyed being part of this experiment and said that science is fun.
Slice of lemon
1. Prepare glasses and different filters (i.e., strainer, tissue paper, cloth).
2. Add a few lemon juice drops to the warm milk.
3. Gently stir the milk until curd is formed.
4. Pour the milk-curd solution into the glasses. Time the process (approx. 30 min).
5. Ask your child about his/her observations:
What happened to milk when we added lemon juice? (chemical reaction of milk protein with acid)
Why some of the filters passed milk/whey faster than the others? (pore-size of the filters)