Curdling Milk
Description: The protease rennin hydrolyzes milk proteins (casein). These insoluble milk proteins form curds, which is a step in cheesemaking. The size of the curds varies with calcium ion concentration. Vinegar also hydrolyzes milk proteins but does so nonspecifically, forming curds that are much smaller than those formed from rennin. The effect of temperature on the protease activity can also be investigated.
Source: Sarquis, J.S., Sarquis, M., ICE Fun with Chemistry; A Guidebook of k-12, Vol. 1
Year: 1991 Vol: 1 Page: 63
Keywords: Rennin, Proteins, Hydrolysis, Casein, Milk, Calcium, Protease
Rating: 
Hazard: Low
- Food grade reagents
- Standard lab conditions
- Skin irritation
- Eye irritation
Effectiveness: Average
- Results are observable with guidance
- Mild effects are seen by audience
- Somewhat connected conceptually to course material
- Primary effects are observed
- Time to results is medium
Difficulty: Medium
- Some manipulations of lab equipment required
- Some intermediate steps to results
Safety Precautions:
- Eye protection required
- Gloves recommended
- Absorbent materials on hand
Class: Biochemistry
Division: General, Biological Chemistry
Home| General Chemistry Demos| Biological Chemistry Demos