Week 2 Lab Group Data, Group A: Cheesemaking

This week, I recorded a couple pages of assorted data throughout our cheesemaking process. Our group was assigned to make the slow-cooking cultured cheese, and we uniquely employed kefir in our cheesemaking. We took care to measure the temperature of our cooking pot, which was quite variable at times. Below is a graph detailing our findings.

The steps were as follows:

1. One gallon of milk was poured into the pot at 1:31 and shortly after we began heating it. Its initial temperature was 50 degrees F.
2. By 1:35 the milk had heated up to 90F, and it continued to rise to 100F at 1:37.
3. By 1:40 the milk’s temperature had risen to 105F, and we decided to take it off the fire at this point to allow it to cool down.
4. At 1:49 the milk had cooled down a bit and its temp was below 100F (98F), so we decided to add the kefir to the mix. For the next hour afterwards, we would be aiming to keep the temperature as close to 90F as possible to simulate a body heat environment.
5. As anticipated, the kefir had a cooling effect on our mixture, with the temperature reaching 92F by 1:52. It continued to drop in temperature, by 2:00 the temp was 90F and by 2:06 the temperature reached 88F.
6. As the temperature began to drop outside of our ideal range, we put the pot back onto the fire at 2:10 and the temperature rose quickly to 95F before we once again took it off to cool.
7. By 2:13 the pot had cooled down again and had a temp of 88F.
8. At 2:49 one hour had passed since the kefir had been added so it was now time to add the dissolved 1/4 cup of rennet water to our mix. We faced issues with the rennet dissolving into the water, so we had crushed it at 1:45 to speed up the process. When we later added the rennet water at 2:49, the pot was at a temperature of 90F.
9. The rennet water had a cooling effect on our mix, bringing the temperature down to 82F at 2:55. To rectify this, we placed the pot back on the fire to reheat it. The pot reached 92F by 3:00, and we took it off the fire again.
10. Our final reheating before the cutting the curds was at 3:13, when the pot had dropped to 84F.
11. At 3:20 we did the “finger test,” but our cheese had already coagulated at the bottom, leaving a layer of whey above it, so we went straight to cutting the cheese. After cutting the cheese curd, we did our first stir at 3:24 and the temperature of our pot was 120F!
12. Instead of stirring every 5 mins like the instructions said, we cut up the largest pieces and stirred it intermittently, aiming to cool down the cheese. I tried our first curd at 3:32, and it tasted, as intended, like cheese.

We also recorded a few weight measurements. When we began, the two containers of milk weighed 2644g together. Each empty container (not including the milk) weighed 437g apiece. The cheese forming container that we placed our finished cheese into weighed (by itself) 51g, and with the cheese it weighed 812g. The next day at 2:55, I recorded the cheese+container as weighing 614g combined, meaning that around 200g had been lost over a 24-hour period. In terms of whey, the green container that we poured it into weighed 377g, and w/ the whey included it was 3204g total.

We would go on to use this whey in making our second cheese, the ricotta. We put our pot w/ whey back onto the fire at 3:55, with the goal of getting the whey to boil. I admit that here my temperature measurements began to stop, as our group solely focused on getting the whey to boil. We added more fuel to our fire to get it hotter, which also had the unfortunate side effect of adding some ash to our whey. By 4:06 our whey had begun to boil, so we added 3/4 cup of cream to the pot and waited for it to boil again. At 4:14 we added 1/4 cup lemon juice to the mix, which almost immediately affected change on our pot’s mixture. We began to see curds forming as the lemon juice helped to coagulate the mix. The temperature of our pot by this time was around 170F. At 4:20 we took our ricotta off of the fire to let it sit and cool down, and shortly after we drained it. With the weight of the cheese cloth included, the ricotta cheese weighed 242g, and at 2:54 the next day it weighed 215g, losing around 30g over 24 hours. Our ricotta whey byproduct weighed 2394g, including the green container’s weight.

One final fun (or gross, I guess) fact is that we had 5 different instances of bugs flying into our cheese throughout this lab. Do not fear, however, as we promptly fished them out.