1/4 cup milk, 1 tablespoon vinegar, Small jar with lid, Coffee filter, Another small container
1. Pour 1/4 cup milk into the jar.
2. Add one tablespoon of vinegar to the jar.
3. Close the lid tightly! Shake the jar to mix well.
4. Position the coffee filter over the opening of the second container, and hold an edge of it with one hand so the filter doesn't "fall in" while you complete step 5.
5. Carefully pour your mixture over the filter.
6. Carefully close the edges of the filter and squeeze the rest of the liquid through the filter.
7. You should be left with curds in the filter. You can squeeze these together and say cheese (but don't eat it)!
Casein is one molecule found in milk. Molecules and atoms are tiny particles that make up everything around us. Vinegar (acetic acid) contains loose hydrogen atoms. The molecules of the milk mix with the loose hydrogen atoms in the acid to create a chemical reaction. The casein molecules in the milk have a negative charge. The loose hydrogen atoms in the acid have a positive charge. Opposite charges attract, so the casein molecules and loose hydrogen atoms group together and make clumps that you can see. The clumps are called curds, and are used to make cheese. The liquid is called whey. Often, bacteria and mold are also added to give cheese more flavor.
- 우유 속의 카세인 분자와 식초 속의 수소 원자가 만나 화학 반응을 일으켜 덩어리를 만드는데 그것이 굳어진 우유 즉 치즈가 되는 것이다.