Week 3 Lab Data Group 5: Cheese

In week 3 lab (conducted on Thursday, April 15, 2026), we made cheese, focusing on the mozzarella making portion of the process.

We began lab by splitting into groups, gathering equipment, and getting our stations set up. This part of the process took 14 minutes.

Procedure Part I:

We then started the cheesemaking by measuring and combining in various ways the ingredients which consisted of:
One gallon of milk
One rennet tablet (to be mixed with ¼ cup water)
1/4 cup vinegar (to be mixed with 2 cups water)

The raw ingredients presented by mass are represented visually below.

_{^{A breakdown of the ratio of ingredients used to produce our cheese. The milk gallon measured directly; the water and vinegar gram values were assumed based on standard volume-mass conversions; and the rennet tablet mass is estimated based on searchable data.}}

This portion of the lab took us around 15 minutes of work and waiting for heating up.

Once the milk was then brought up to a temperature of 90 degrees Fahrenheit at which point the rennet water was added. This temperature was then maintained to the best of our ability for 31 minutes.

_{^{Temperature of pot starting from initial heating through the separation of curds and whey, through which time we attempted to maintain a 90 degree internal temp through moving the pot on and off the fire.}}

As seen, the system of placing and removing the pot from the fire made it difficult to maintain ideal temperatures.

After 31 minutes, we checked if the curds had solidified and noted a “clean break.” At this point, we cut the cheese into ~2cm² cubes and maintained a temperature of 90 degrees while stirring occasionally for 17 minutes.

Then, we strained the contents of the pot through a cheese cloth, colander, and funnel placed over jars. This separated the curds and whey. The final end products were then weighed respectively to determine their quantities as shown below.

^{A breakdown of the ratio of product left after the Part I process. The curds and whey quantities were measured directly while the mass lost was the remaining gram value of our initial ingredients.}

A significant amount of mass (17.5%) was lost throughout the cooking process. This is due to a combination of whey spillage when dumping and straining, residue in pots and containers, as well as minimal loss to evaporation throughout.

This last step of the initial process took a total of 25 minutes, meaning we did not give our curds a full 30 minutes to set and strain which may have impacted our result in Part 2.

Procedure Part 2:

Our station was then dedicated to the production of mozzarella from the curds. The whey from Part 1 was placed back into the pot and reheated to reach 150 degrees. This took 16 minutes to accomplish between building up the fire and waiting for the whey to heat.

We also combined:
1/4 Cup of salt
2 Liters of cool water
to a bowl to serve as a cool salt bath.

The pressed curds were also cut into 3/4 inch pieces (our initial attempt was cubes of this size, but as we learned and later adjusted to do, it should have been slices). These were then placed in the water for 5 minutes, after which they were taken out and stretched/kneaded a bit. These were then placed back in the water for approximately 1 minute before being taken out and stretched again. Lastly, the product was then dipped back into the hot water before being placed in the salt bath to cool.

Our attempt at making mozzarella was unsuccessful, but was a very useful “practice” of sorts for the rest of the groups who later came through. While other groups should have more concrete data on their respective results. We noted that the most successful product came from the curds that seemed the most hard pressed and the highest water temperature. (Neither of these things were the case for our attempt, as quite the opposite, going first meant less time for the curd to set and less time for the water to heat over 150 degrees).

While watching the whey for other groups’ turns, the water fluctuated between a thermometer readout of 145 degrees and 175 degrees. However, we noted at least one occasion where the liquid near the rim of the pot was beginning to boil, implying local temperature of up to 212 degrees.