Cheese Lab Conclusion

What are the optimal conditions and curdling agents for making cheese?

CER: The best curdling agent to use is Chymosin in a hot, acidic environment. In the lab, Chymosin curdled the milk in 5 out of the 6 conditions. This shows that the milk may continue to curdle even if something happens to the machine that keeps the enzyme’s environment in check. The environment should be hot because in the lab, the hot environment produced curdling in 5 minutes for Chymosin. Also, the environment should be acidic because during testing, chymosin produced curds in 5 minutes when it was in an acid. If hot and acidic make the enzyme produce curds faster, then a hot and acidic environment would be best from a manufacturing perspective because cheese could be produced very fast.

Possible Errors: Some possible errors may result from different people’s armpits, and accidents during timing the incubation. The temperature of the underarm varies slightly from person to person and some groups didn’t even put the test tube in their armpit. The effect of this may be that the enzymes in some tubes may have been more active than others and would eventually result in inconsistencies in the time for curdling. When I ended the the 10 minute timer for one of the incubation rounds, I forgot to immediately restart it. This means that the timing of that round was slightly off. If everyone made small mistakes like these, then overall it could create a large timing difference which would skew the results. To prevent inaccuracies in time from occurring, I would alter the procedure of this experiment in 2 ways. One thing I would do is put all of the test tubes in an incubator with a steady temperature to prevent differences from underarm to underarm. Another thing I would change is the way we time. I think that the timer should run for 10 minutes, then have a 10 second pause to check for curds, and then restart its 10 minute cycle. This would prevent the humans from forgetting to restart the timer.

Practical Applications: The purpose of this experiment was to understand how different factors such as pH and temperature can affect the activity of enzymes. This relates to what I’ve learned in class because in 8th grade we learned about pH and hydronium ion concentration. This makes me think about why and how hydronium can affect enzymes. The results of this lab could be applied to making cheese at home. I have already made cheese at home many times, but only used buttermilk. Now I know that if I want the quickest outcome, I could purchase some chymosin or rennin.

	Chymosin	Rennin	Buttermilk	Milk (Control)
Acid	5	5	5
Base	20
pH Control	15	10
Cold
Hot	5	5
temp. Control	10	10