Cheese room. Stainless steel (SS) vat in the middle. To the right are 3 molds with last night's production.

Open mold with the weight and cheese cloth removed.

Why do we make cheese?

The same reason mankind has been making it time out of mind, to preserve the milk. My neighbor has a small dairy and creamery, about 20 head of Jersey, known for their rich milk, about 4% butter fat and 12% total milk solids.

Currently, twelve cows are milked twice a day. Each cow produces about 3.5 gallons of milk per milking or about 7 gallons per day, so the 12 cows produce 84 gallons a day.

The tourist season runs from June through leaf season, about mid October, to Thanksgiving. What to do with the excess milk the rest of the year? Perserve it by turning it into cheese and sell it to the visitors next season.

We make Cheddar, Colby, Havarti, Feta, Gouda, Mozzarella and Cottage Cheese, but mostly Cheddar.

And How?

Here are some of the steps in the stirred curd cheddar cheese making process.

In the middle of the cheese room is a jacketed (double wall) stainless steel (SS) vat. It was originally designed for cottage cheese production. The vat holds 100 gallons. Milk weighs 8.6 lbs per gallon so when full, contains 860 lbs of milk.

If you look closely, at the back of the vat there are three pipes: cold water, hot water, and steam. These are injected into the jacket to control the setting and cooking temperature. To the right of the vat are 3 SS molds. They are sitting on inverted 5 gallon buckets with a 3 gallon bucket of water on top for weight to press the cheese curd back together.

Floating in the vat is a digital thermometer. Sticking out of the vat is the handle of a SS paddle used to stir the milk. On the front is a drain valve which will be used to drain the whey. The slot in the floor below the vat is a food drain. Everything dumped in there goes to a collection tank where a sump pump sends it over the river and through the pasture to a waste lagoon.

The first step is to wash and sanitize the vat, fill it with raw milk, crank up the steam and bring the milk from 37 degrees F to 88 degrees F when we will add the culture.

Tonight we will make cheddar, but first I need to get last night's cheese out of the way.

Packet of freeze dried culture.

The Culture

What's the difference between this place and yogurt?

Yogurt has a live culture ...

After the milk is raised to 88 degrees F, the culture is added. We use freeze dried Choozit brand from Danisco (formerly Ezal). Different cheeses call for different cultures.

For Cheddar, Colby and Feta we use type MA which contains Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. cremoris. For Havarti we use type MM which contains Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris, and Lactococcus lactis ssp biovar diacetylactis.

Both of these are mesophilic (moderate temperature loving) cultures. They grow best at 88 to 90 degrees and are killed by temperatures above 100 degrees.

We buy the 250 Danisco Culture Unit (DCU) packages and use one half a package or 125 DCU per 100 gallons of milk.

Setting the milk (25 mins.)

Adding the rennet

Rennet comes in different strengths: single, double (2x) and tripple (3x). 60 ml of single strength is the same as 30 ml of double strength or 20 ml of tripple strength. We have switched from single strength to double strength so the amounts listed below would be cut in half. There is a significant cost savings in using double strength over single strength.

The rennet is carefully calculated (90 ml per 1000 lbs of milk), diluted about 50:1 with chlorine free water, added to the milk, and stirred. Too much rennet produces a rubbery cheese so through experimentation we have learned to cut the amount of rennet by 20% so I actually add about 70 ml per 1000 lbs of milk (35 ml of 2x).

Curd formation (30 mins.)

Cutting the curd (5 mins.)

Wire knives, or harps, are used to cut the curd. First it is cut into horizontal ribbons with one knife. Then it is cut twice with a vertical knife, once lengthwise, then again crosswise. The result is cubes about 3/8" to 1/2" square, depending on the wire spacing of the knife. The knife size is one of the variables that can be used to control the amount of moisture in the cheese. In general, the smaller the cubes, the dryer the cheese; the larger the cubes, the more moisture.

Almost immediately the whey and curd begin separating. The curd is very soft and fragile. It will shatter if dropped on the floor. Dropping it on the floor is a simple test used to gauge the firmness of the curd.

Cooking (60 mins.)

Different cheeses have different cooking times and temperatures. For cheddar we raise the temperature from 88 degrees to 100 degrees at the rate of 2 degrees every 5 minutes by regulating the amount of steam that goes into the jacket. The vat is gently stirred to keep the curd from matting and to keep the curd evenly heated. This takes 30 minutes to get the temperature to 100 degrees. Then the steam is shut off and the vat held at 100 degrees for another 30 minutes so the total cooking time is 1 hour.

Calling this "cooking" is a little strange to me since at the end of cooking, the curd and whey is just lukewarm eventhough the walls of the vat are quite hot from the steam. The steam must be cut off before the vat reaches 100 degrees as the temperature will "coast" up as the curd and whey absorb the heat from the metal.

Cooking causes the curd to express more whey and become firm. Within a short time, the curd will no longer shatter when dropped on the floor.

Draining (30 mins.)

The whey is drained off and usually thrown out by pumping it to a waste lagoon. The creamery is not large enough to justify the equipment necessary to process it. I have recently started raising hogs to utilize this high protein waste.

Cheddaring (2 hours - 3 hours)

Cheddar, like most cheeses, is named for the region or town where it originated. In Cheddar, England, they learned that if they delayed the salting a few hours, the cheese had a lower spoilage rate. This delay is know as cheddaring.

Today we know the culture converts the lactose sugar in the milk to lactic acid. The longer the culture is allowed to grow, the more sugar is converted to lactic acid. This is similar to the fermentation process in wine or beer except different organisms are used (a bacteria instead of yeast). Eventually, all the sugar would be converted, the acidity would increase and the lack of food and high acidity will kill the culture. This is one of the reason cheese stores well as the high acid content also prevents other spoilage bacteria from growing. Many people are lactose intolerant and can't drink milk. They may be able to eat cheese since it has less lactose.

In modern cheese plants, the curd is allowed to mat back together and then cut into slabs, which are stacked on top of each other while the curd drains. After cheddaring, the blocks of curd are run through a food mill that cuts the curd back into small pieces so it can be uniformly salted.

The alternative is to prevent the curd from matting together by stirring. This process, known as stirred curd cheddar, is an older method of producing cheddar.

During cheddaring the amount of acid is monitored by using pH paper, an electronic pH meter, or by titration. Titration seems to work best for us.

According to Kosikowski and Mistry, Cheese and Fermented Mild Products, optimum curd pH for cheddar is 5.2 to 5.3 before milling (5.4 to 5.5 at salting for stirred curd). Recommended titratible acidity (TA) for cheddar: Pasteurized Milk: .5 to .6; Heat Treated Milk: .65 to .7; Raw Milk: .6 to .7 but extend to .8 if gas holes or unclean flavor are detected in the curd. In contrast, Colby, which is made similar to cheddar, should be salted at .22.

The speed at which lactic acid develops is critical. A very rapid rise is not desireable as the high acid dissolves too much of insoluble calcium phosphate (a buffer) and a low pH cheese develops an intense acid flavor with a weak pasty texture know as "wet acid."

Cheese can be made "by the clock" (I did, the first year I made it), but for cheddar it is nice to be able to measure the acidity as it builds up during cheddaring. Below are two Make Sheets that illustrate the different time vs acidity curves that occur during different conditions.

In general, at higher acidities (TA greater than .6 to .70, the cheese will be dryer, crumblier and tangier but some of the rich flavor will be gone. At lower acidities (TA around .35), the cheese is more moist and has a fuller flavor.

Salting

After the acid builds up to the desired level, the curd is salted. The salt kills the culture and stops the production of acid at the desired level, helps preserve the cheese and improves the taste.

The amount of salt to be added is calculated based on a percentage of the expected weight of the cheese (usually 1.8 percent). The salt is applied in three applications and stirred well between each application to ensure that the curd is evenly salted. Some of the salt will be lost during pressing as the whey continues to drain, yielding a final salt concentration of 1.5 percent.

If herbs or spices are to added to the cheese, they will be added now. Some of the flavors added are basil, chives, dried tomatoes, jalapeno, habenero, dill.

Filling the molds

Pressing

To be continued ...