Cheese Lab Conclusion

In this lab we asked the question “what are the optimal conditions and curdling agents for making cheese?” We found that in order for milk to curdle, the best conditions would be to have a warm and acidic environment. When the milk with chymosin was put in hot water, it curdled within five minutes comparing to when it did not curdle within twenty minutes in the cold water. When it was put into a person’s armpit, it curdled within ten minutes. It was neither cold nor hot so it took a little more time to curdle than the hot, but much less time than the cold. Chymosin was the same outcome as rennin, however, rennin took a little longer to curdle. The chymosin and rennin had the exact same results except for the base. Chymosin took a long time to curdle, but the rennin did not curdle at all. Chymosin took twenty minutes while the rennin did not fall within the time range. This data supports my claim because it shows that milk curdles the fastest when put in warm conditions with a low pH level, the milk curdles the fastest.

While my hypothesis was supported by our data, there could have been errors due to time and warmth. The milk could have curdled faster than the amount of time we gathered because we only checked the milk every five minutes. The milk could have curdled before we checked on it causing the data to be somewhat inaccurate. For example, we said that the milk with chymosin in hot water curdled at five minutes; however, it could have curdled at two minutes or three minutes. Another issue could have been that when people put the test tube under their armpits, some people could have been wearing jackets while others were wearing tank tops. If someone was wearing a jacket, it would cause their armpits to be much warmer and therefore make the milk curdle faster. On the other hand, if someone was wearing a tank top, it would curdle slower. Due to these errors, in future experiments I would recommend to either constantly stand by the milk to see if it curdles or to check it more often and have everyone either  wear a jacket, or put the test tube on their bare skin.

This lab was done to demonstrate which conditions and curdling agents would make the milk curdle the fastest. From this lab I learned that in order for milk to curdle and turn to cheese, the milk needs to be put in a warm environment with an acidic curdling agent. Although chymosin and rennin work almost exactly the same, chymosin is the better curdling agent because it works slightly faster than rennin. After all, time is money. We learned in class that chymosin is found in calves and the milk that they ingest. Inside of a calf’s stomach, it would be very warm and acidic. In the lab we put the milk in warm water, and we added the chymosin to the milk in order to make it acidic. This lab experiment could be applied to other situations such as in cheese factories to show which curdling agent works best and in what environment or to teach milk factories how to make sure their milk stays fresh.

  Time to Curdle (minutes)

Curdling Agent:	Chymosin	Rennin	Buttermilk	Milk (control)
Acid	5	5	5
Base	20
pH Control	15	10
Cold
Hot	5	5
Temp. Control	10	10