Cheese Processing: Time, Tips, And Tricks

The time it takes to process cheese depends on the type of cheese being made. For example, the time it takes to process cheddar cheese is vastly different from the time it takes to process ricotta or mascarpone. However, all cheese-making follows the same general process, especially in the earlier steps. The first step is to prepare the milk, which may involve manipulating the protein-to-fat ratio and pasteurizing the milk. The second step is to acidify the milk by adding cultures, which will cause the milk to ferment and become more acidic. The third step is to curdle the milk by adding rennet, which will cause the milk to coagulate and form curds. The fourth step is to cut the curds, which creates more surface area and allows the curds and whey to separate. The fifth step is to process the curds by stirring, cooking, and/or washing them, which helps to acidify and dry them. The sixth step is to drain the whey, leaving only the solid curds. The seventh step is to salt the cheese, either by sprinkling on dry salt or submerging the cheese in a brine solution. The eighth step is to shape the cheese using molds. The ninth and final step is to age the cheese, which can take anywhere from a few days to many years.

Preparing the milk

The quality of the milk you use will determine the quality of your cheese, so it's important to start with good, fresh milk. If you're on a dairy farm, you can use milk that's still warm from the udder, but otherwise, you'll need to heat it slowly in a large pot on the stove. The milk should be heated to 86°F (or 90°F if using raw milk) and kept at this temperature for 90 minutes. This can be done by creating a water bath in your sink or pot, adding a little boiling water from a kettle to maintain the temperature.

Once the milk has reached the correct temperature, it's time to add the starter culture. This can be done by sprinkling the powder over the surface of the milk and allowing it to rehydrate for about 2 minutes before stirring it in. The culture will begin to convert the lactose in the milk to lactic acid.

At this stage, you can also add calcium chloride if using pasteurized milk. This will help to firm up the curds and improve the yield of the cheese.

If you are using raw milk, it is recommended to decrease the amount of culture added by 25-40% as raw milk naturally contains bacteria that will contribute to the cheese-making process.

Acidifying the milk

The first step in making cheese is to acidify the milk. There are two ways to do this: direct acidification and adding cultures.

Direct acidification involves dumping acid (vinegar or citric acid) into the milk to achieve the correct level of acidity. This process leads to soft cheeses such as ricotta and mascarpone.

The other way to acidify the milk is to add cultures, or living bacteria. Given time, warmth, and no competing bacteria, these cultures will consume the lactose in the milk, converting it into lactic acid. This is also known as ripening the milk. The bacteria will continue to produce lactic acid until it reaches a level of acidity where the milk curdles and becomes what we call 'spoiled or rotten milk'. The milk can also be ripened by adding a coagulant like rennet, which causes the proteins in the milk to link together and form a gel. The longer you ripen the milk, the more culture there will be, and the faster it will work.

The pH of the milk is an important factor in the cheese-making process. The pH level can determine how fast the rennet forms a curd, how hard the curd gets, and how much moisture it holds. The pH level also affects the ease of draining the curd and closing the rind. A pH level that is too low can result in crumbly, sour, and cracked cheese. Therefore, it is crucial to monitor the pH level during the milk acidification process to ensure the desired consistency and texture of the cheese.

To achieve the correct level of acidity, you can use pH strips or taste and smell the milk. By letting the milk sour a little before adding rennet, you can speed up the curd formation. However, this also creates a race against time as the more acidic the curd becomes, the more challenging it is to mesh the curds back together into the cheese. Thus, it is crucial to drain the cheese before the pH drops too much.

Curdling the milk

Curdling milk is the process of separating the milk solids (curds) from the liquid (whey). This can be done by adding an acid, such as lemon juice or vinegar, to the milk, or by adding a coagulant like rennet, which causes the proteins in the milk to link together and form a gel.

To curdle milk for cheese, start by heating the milk to around 86°F (30°C). You can do this by placing the milk in a pot of warm water or on a stovetop over low heat, stirring constantly to ensure even heating. Once the milk has reached the desired temperature, remove it from the heat source.

The next step is to add the coagulant or acid. For most cheeses, the coagulant of choice is rennet, an enzyme that can be derived from animal, bacterial, or fungal sources. Mix the coagulant into the milk and wait for the milk to transform from a liquid into a gel. This may take up to 45 minutes, and you can test the "doneness" of the gel by pressing gently on the surface of the milk with a clean hand.

Once the gel has formed, it's time to cut the curd. This involves cutting the gelled milk into smaller cubes or chunks, which can be done with a knife, a "cheese harp," or even a whisk. The size of the curds will affect the moisture content of the final cheese, with smaller curds resulting in a drier, more ageable cheese.

After cutting the curd, the mixture will need to be stirred and cooked. This step can vary depending on the recipe, but it typically involves stirring the curds for several minutes to an hour while gradually increasing the heat. Stirring and cooking help to develop the acid inside the curd and dry out the cheese.

Finally, the curds and whey must be separated. This can be done by draining the mixture through a colander or cheesecloth. Allow the mixture to cool slightly before draining, and then rinse the curds with cold water to stop the cooking process and prevent graininess.

The length of time it takes to curdle milk can vary depending on the method used, the type of milk, and the desired outcome. However, the entire process of curdling milk for cheese typically takes around an hour or two, including the time needed for heating, adding coagulants or acids, cutting the curd, stirring and cooking, and separating the curds and whey.

Cutting the curd

The next step in the cheese-making process is cutting the curd. The curds and whey mixture is allowed to separate and ferment until the pH reaches 6.4. At this point, the curd should form a large coagulated mass in the cheese-making vat. The cheesemaker then uses long curd knives to cut through the curds. Cutting the curd creates more surface area on the curd, which allows the curds and whey to separate more effectively.

Cheesemakers usually make crisscrossing cuts vertically, horizontally and diagonally to break up the curd. The size of the curds after cutting can influence the cheese's level of moisture. Larger chunks of curd retain more moisture, leading to moister cheese, and smaller pieces of curd can lead to drier cheese. The next step is to cut the curds into small cubes or chunks. This can be done with a 'cheese harp', a knife or even a whisk. The size to which you cut the curds will dramatically affect the amount of moisture retained in your final cheese; the smaller the initial pieces, the drier (and more ageable) the cheese will be.

Once the curds have been cut as close to your target size as possible (they will shrink as they cook), allow them to rest for about 5 minutes, without stirring, while the surface hardens a little. The next step is to begin a slow stir for about 10-15 minutes, as the curds are still very fragile. Bring the curds back to 86°F at this time if they have cooled. This is to firm the curds well enough to keep them intact during the scald, or cooking phase, that comes next.

Draining the whey

There are different methods for draining the whey, depending on the type of cheese being made. In some cases, cheesemakers allow the whey to drain off naturally, without applying any external force. This method is often used for softer cheeses that require a higher moisture content.

However, for harder cheeses that need a lower moisture content, additional techniques are employed to facilitate the removal of whey. One common method is to use a mold or press, which applies pressure to the curds. This pressure compacts the curds, forcing out more whey and creating a denser, drier final product.

The duration of the draining process can vary depending on the desired texture and moisture level of the cheese. For harder cheeses, the draining time is typically longer to ensure that a sufficient amount of whey is removed. On the other hand, softer cheeses may require a shorter draining time to retain the desired level of moisture.

During the draining process, cheesemakers also need to maintain the temperature of the curds. If the curds get too cold, they can become difficult to work with and may not form a smooth wheel. Therefore, it is crucial to work quickly and efficiently during this step to ensure the curds remain warm and pliable.

Once the whey has been drained, the curds should form a large mat or slab. At this stage, cheesemakers can proceed to the next steps in the cheese-making process, such as cheddaring, salting, or shaping the cheese. The efficient draining of whey is crucial to achieving the desired texture, moisture content, and overall quality of the final cheese product.

Frequently asked questions