Cheese Lab Conclusion

In the lab in which we researched which conditions and which curdling agents would be optimal for making cheese. We tested four curdling agents: chymosin, rennin, buttermilk, and milk as a control. To see which pH conditions were best, each curdling agent was tested in acidic conditions, basic conditions, and a neutral pH control. In order to find out which temperature conditions were optimal for the enzymes to work best, each curdling agent was also tested in a hot temperature, a cold temperature, and temperature control. We found that chymosin and rennin are the most effective curdling agents, and their optimal conditions are in warm and acidic environments. The lowest curdling time in the experiment was found under acidic and warm conditions, the lowest time being 5 minutes. Under many of the conditions we tested, such as basic and the controls, the only curdling agents which produced curds were chymosin and rennin. Milk did not produce any curds in 35 minutes, our given amount of time, while buttermilk only produced curds in acidic conditions. Rennin is an enzyme which in found in the lining of a baby calf’s stomach, in which the conditions are warm and acidic. This explains why warm and acidic conditions were optimal. This data support our claim because the numbers show that chymosin and rennin produced curds in the least amount of time (5 minutes) in a warm and acidic environment.

While our hypothesis was supported by the data, there could have been errors due to the fact that we checked for curds every 5 minutes. The data shows that under acidic conditions, chymosin, rennin, and buttermilk all curdled in exactly 5 minutes. This is a false conclusion to make because it is highly possible that one or more of the curdling agents curdled before 5 minutes. However, we did not account for this because we only measured time every 5 minutes. This was probably an accuracy error. To avoid this error we could have checked for curds every 2 or 3 minutes instead of 5. Also, there was some error in lack of accuracy in timing. We added the acid, base, and water control to each test tube at slightly different times, and more time had passed still by the time we recorded our initial time and officially started the five minutes. This may have affected the experiment in that the first time we checked for curds, it had probably been more than five minutes. In our data, it shows that buttermilk, rennin, and chymosin all curdled in 5 minutes in the acidic conditions. This may not have actually been true. In the future, it will be better to be more prompt with added the acids and bases and recording the initial time.

This lab was done to demonstrate an understanding of how enzymes work and how they speed up chemical reactions. From this lab I learned that there are clear differences in the results when enzymes are in their optimal conditions, which helps me understand the concept of how enzymes work best in their optimal pH and optimal temperature. Based on my experience in this lab, I now understand that to produce best results, it works well to use as many substrates and enzymes as possible, in their optimal conditions.

	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