Cheese Lab

9-21-15

Analysis

In this lab we asked the question, “What are the optimal conditions and curdling agents for making cheese?” We made the claim that if a cow’s stomach, where renin is found, is warm and acidic, then renin will contribute to the making of cheese best in a warm environment with a pH lower than 7. We found that renin caused the fastest curdling time but chymosin was the most consistent, making curdles in almost every situation. For example, renin curdled the milk by 5 minutes in the hot and acidic environments but didn’t curdle at all when the milk was in basic and cold areas. But, the chymosin, curdled at the same rates and more, having curdles by 20 minutes in the basic environment. The reason the milk curdled quicker in the acidic and hotter environments were because these factors denatured the enzymes quicker. This data supports our claim because the enzymes chymosin and renin, were affected by the pH and temperature, to curdle faster.

While our hypothesis was supported by our data, there could’ve been errors due to inconsistency in checking for curdles. We checked in five minute increments, but the fastest curdling agents and environments could have curdled in four, three, two, one, or even less than one minute. This error is pretty unavoidable because every time we checked, we would have to take the experiment out of its environment but I think checking more often would result in more accurate data. Another hypothetical error could’ve been forgetting to invert the test tube 3 times after adding the curdling agent, something our group almost forgot to do. This could’ve ruined the data accuracy because the curdling agent would me more concentrated in some places more than others. To avoid this error, simply follow directions! One suggestion for the next lab would be to have one hot and cold station per group to reduce the risk of getting test tubes mixed up or broken while walking across the room.

This lab was done to demonstrate the different factors including changing pH, temperature, and curdling agents, that can influence enzymes in milk. We applied what we learned in class about changing substrates, which in this lab were the renin, chymosin, and buttermilk, or pH and temperature, to have faster or slower results. From this lab I learned about changing the activation energy by using different variables which helped me understand the concept of the chemical reactions we covered this unit. Based on my experience from this lab, I applied that when baking, the food will be made quicker under hotter circumstances because the temperature speeds up the chemical reaction.

Class Data	Time to Curdle	(minutes)
Curdling Agent:	chymosin	rennin	buttermilk
Acid	5	5	5
Base	20
pH control	15	10
Cold
Hot	5	5
temp control	10	10