Group E Week 2 Data: Cheesemaking

Group E: Grace Brindle, Zach McCrary, John Hoffman, Zoe Orlin
Data Recorder: Grace Brindle
Date: April 8, 2021
Location: Mai Fete Island, Carleton College, Northfield, MN
Weather: 63° Fahrenheit, partly cloudy, 11 miles per hour winds SE

Part I: Creating Cheese Curds and Whey

Initial Measurements

Milk weight:
Container 1 (empty): .905 kilograms
Container 2 (empty): .910 kilograms

Container 1 (milk + container): 2.845 kilograms
Container 2 (milk + container): 2.865 kilograms

Milk (subtracting container’s weight):
Container 1: 2.845 – .905 = 1.940 kilograms
Container 2: 2.865 – .910 = 1.955 kilograms
Total: 1.940 + 1.955 = 3.895 kilograms

Milk volume: 1 gallon

Vinegar weight:
¼ cup weight (without vinegar): .02 kilograms
Cup with vinegar: .08 kilograms
Total: .08 – .02 = .06 kilograms

Process

Heating the Milk Before Adding Rennet

We began this process by slowly adding two cups of water and a quarter cup of vinegar to a gallon of milk in a cast iron pot, stirring the mixture as we poured. We then put the pot on a grate over the fire pit and waited for the milk to reach a temperature of 90℉ as indicated by a thermometer. The table below indicates the measurements taken while the milk warmed before the rennet was added.

Time	Time Elapsed	Milk Temperature	Notes
2:05	0 minutes		Began heating the milk
2:08	3 minutes	80℉	Bits of ash are in the milk
2:09	4 minutes	90℉	Moved the pot off of the fire
2:10	5 minutes	96℉	Rennet tablet finished dissolving in 1/4 cup of water
2:11	6 minutes	94℉	Slowly added the rennet water to the milk and took the pot off the fire

Waiting for the Curd to Form

After adding the rennet, we had to wait approximately 15 minutes for the curd to form. The table below shows the measurements taken during this step; we successfully achieved a clean break of the curd after 16 minutes.

Time	Time Elapsed	Milk Temperature	Notes
2:11	0 minutes	94℉	Rennet added
2:16	5 minutes	93℉
2:21	10 minutes	93℉
2:22	11 minutes	92℉
2:25	14 minutes	91℉
2:26	15 minutes	91℉
2:27	16 minutes		Achieved a clean break of the curd
2:28	17 minutes	90℉	We cut the cord horizontally, vertically, and underneath with a knife
2:31	20 minutes	89℉	We finished cutting the curd

Waiting for the Cut Curds to Solidify

After cutting the curd, we had to let the curds sit in the pot to firm up.

Time	Time Elapsed	Curd Temperature	Notes
2:32	0 minutes		We stirred the curds
2:33	1 minute	87℉	We put the pot on the fire to let the curds heat up because the temperature dropped below 90℉
2:37	5 minutes	86℉	We periodically stirred the curds as we waited for them to get more solid
2:38	6 minutes	90℉
2:42	10 minutes	100℉	We took the pot off of the fire because it had gotten too hot
2:48	16 minutes		We strained the curds and the whey through a colander into a bucket

At this point, we let the curds sit in the colander so that any remaining whey could continue to drain into a bucket and the curds could continue to solidify. We periodically funneled the whey from the bucket into the empty milk containers as more whey separated from the curds over time. We noticed the curds definitely grew firmer over time, particularly around the edges where they began to clump together. We began this process at 2:48pm and concluded the process at 3:43pm, taking 55 minutes total. The curds were 69℉ and the whey was 75℉.

Final Measurements

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Whey weight:
Container 1: 2.780 kilograms
Container 2: 2.290 kilograms

Container 1 (subtracting container’s weight): 2.780 – .905 = 1.875 kilograms
Container 2 (subtracting container’s weight): 2.290 – .910 = 1.380 kilograms
Total whey yield: 1.875 + 1.380 = 3.255 kilograms

Whey volume: .75 gallons (approximately)

Curds weight: .928 kilograms

Input	Output
3.895 kilograms of milk	3.255 kilograms of whey
.06 kilograms of vinegar	.928 kilograms of curds
2 cups of water

Part II: Creating Whey Cheese

Initial Measurements

Whey weight:
Please note that we added whey from another group to Container 2 so we would have enough whey (approximately 1 gallon) to make the whey cheese. As such, the whey we used for the whey cheese was more than our whey yield for Part I.

Container 1: 2.780 kilograms
Container 2: 2.810 kilograms

Container 1 (subtracting container’s weight): 2.780 – .905 = 1.875 kilograms
Container 2 (subtracting container’s weight): 2.810 – .910 = 1.900 kilograms
Total whey used: 1.875 + 1.900 = 3.775 kilograms

Whey volume: 1 gallon (approximately)

Curds weight: .231 kilograms
We used 25% of our curd yield from Part I for our whey cheese.

Vinegar weight:
¼ cup weight (without vinegar): .020 kilograms
Cup with vinegar: .083 kilograms
Total: .083 – .020 = .063 kilograms

Process

To make the whey cheese, we combined the curd and whey from Part I in our pot and placed it over the fire. We then waited for the mixture to come to a boil and added vinegar. After five minutes, we took the pot off of the fire and strained the whey cheese through a colander. The table below lists our precise steps and measurements.

Time	Time Elapsed	Whey-Curd Temperature	Notes
3:45	0 minutes		We put the pot on the fire and waited for it to boil
3:48	3 minutes		We added logs to make the whey-curd mix hotter
3:49	4 minutes	90℉
3:55	10 minutes	136℉
4:01	16 minutes	150℉	We put the pot lid on the pot to help the mixture boil faster
4:07	22 minutes	180℉	We removed the thermometer from the pot so the pot lid could completely seal
4:09	24 minutes	190℉	We believed the whey-curd mix had boiled and added the vinegar, taking the pot off the fire
4:11	26 minutes (2 minutes after vinegar added)	150℉
4:15	30 minutes (6 minutes after vinegar added)		We poured the whey cheese into a colander

Final Measurements

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Whey weight:
Container 1: 2.275 kilograms
Container 2: 2.365 kilograms

Container 1 (subtracting container’s weight): 2.275 – .905 = 1.370 kilograms
Container 2 (subtracting container’s weight): 2.365 – .910 = 1.455 kilograms
Total whey remaining: 1.370 + 1.455 = 2.825 kilograms

Whey cheese weight: .263 kilograms

Input	Output
3.775 kilograms of whey	2.825 kilograms of whey (-.950 kg)
.231 kilograms of curds	.263 kilograms of curds (+.032 kg)
.063 kilograms of vinegar

Qualitative Results

The whey cheese appeared pretty similar to our cheese curds from Part I and it was difficult to tell a difference, which caused us to wonder if we failed to process the whey cheese. If we did, we believe that this failure was because our mixture did not reach a high enough temperature to properly boil; the placement of the pot lid may have tricked us into thinking it was boiling due to the release of pressure. However, the curds did look slightly softer after Part II. The ‘whey cheese’ tasted mostly like milk with a slightly sweet aftertaste.