The Art Of Fermenting Cheese: Timing Is Everything

Fermentation is a crucial process in cheesemaking, and the time it takes to ferment cheese varies depending on the type of cheese being made. The fermentation process involves adding bacteria to dairy products, allowing them to consume lactose (milk sugar) and produce lactic acid, which curdles the milk and separates it into curds and whey. The duration of fermentation can range from a few hours to several days, weeks, or even months, depending on the desired cheese variety and its complexity.

For example, fresh cheeses like cream cheese, paneer, chevre, mozzarella, and ricotta typically require a shorter fermentation time, while aged cheeses such as cheddar, blue cheese, and Swiss cheeses need a more extended period due to the ageing process. The ageing process can take anywhere from a few weeks to several months or even longer, depending on the specific cheese variety.

Characteristics of Cheese Fermentation

Fermentation times vary depending on the type of cheese

Aged cheeses, such as cheddar, blue cheese, and Swiss, take longer due to the ageing process. This can range from a couple of weeks to nearly 12 months or even longer. For instance, Monterey Jack is usually ready after one month of ageing, while Parmesan requires at least 9 to 12 months. Bries and Camemberts are typically aged for about 6 weeks, and Blue Cheese may take from 3 to 5 months.

The fermentation time also depends on the temperature and humidity of the environment. For example, Kaltbach Le Gruyere is aged in a cave for a year, where the temperature is consistently between 50 and 53 degrees Fahrenheit, with 96% humidity. This unique environment gives the cheese its distinct aroma, dark rind colour, smoothness, flavour, and creamy texture.

The type of milk used also plays a role in determining the fermentation time. Cow's milk, for instance, is typically cooled to a fermentation temperature of 29-31 degrees Celsius for making Cheddar, while thermophilic starters like Lactobacillus helveticus are used for cheeses like Emmental and Parmesan, which require a higher incubation temperature.

The ripening process

During ripening, the cheese is dominated by non-starter lactobacilli, and a complex combination of bacterial and enzymatic reactions gives the cheese its characteristic flavour. The enzymes and bacteria continue to modify proteins, fats and sugars in the cheese.

The length of the ripening process depends on the type of cheese being made. For example, fresh cheeses like cream cheese, paneer, chevre, mozzarella, and ricotta take a much shorter time to prepare than aged cheeses such as cheddar, blue cheese, and Swiss.

Aged cheeses undergo additional steps during the ripening process, such as waxing, bandaging, or washing. Waxed cheese is air-dried and then coated in cheese wax. Bandaged cheese is covered in butter muslin and coated in fat. Washed cheese is regularly wiped down in a salty brine.

Overall, the ripening process is a critical step in cheesemaking, allowing the development of flavour and texture and ensuring the safety and longevity of the final product.

The role of bacteria in fermentation

The process of cheese fermentation involves the metabolic consumption of sugar in the absence of oxygen, with microbes producing energy by transforming chemical components. In the case of cheese, this means eating lactose (the sugar in milk) and producing acid.

The first step in the fermentation process occurs when milk is inoculated with lactic acid bacteria (LAB) and rennet in a vat. The LAB converts the lactose in the milk to lactic acid, which, along with the rennet, causes the milk to curdle. This separates the curds (made of milk solids, fats, and proteins) from the whey (mostly water). The curds are then soaked until the lactic acid bacteria create the right concentration, after which the whey is drained off. The curds are then pressed, salted, and mixed with different types of secondary microflora before being sent for aging.

During the aging process, enzymes and bacteria continue to modify the proteins, fats, and sugars in the cheese. For example, particular bacteria fermenting remaining lactose in the cheese can produce carbon dioxide, resulting in the holes found in Swiss cheese.

The role of bacteria in cheese fermentation is crucial, as they are responsible for initiating the fermentation process and producing acids that give cheese its distinctive taste. Bacteria also contribute to the development of flavour, texture, aroma, and colour. For instance, the white surface mold found on cheeses like Brie or Camembert is due to the complex ecosystem of at least four different microbes, with one of them, Geotrichum candidum, stimulating sulfur flavour and influencing the thickness and texture of the rind.

Additionally, bacteria play a vital role in the ripening process, with a second wave of diverse bacteria and fungi (secondary microbiota) growing within the cheese and on its surface, sometimes forming a rind. The microorganisms in the secondary microbiota contribute enzymatic activities that further affect the cheese's colour, flavour, texture, and other characteristics.

Overall, the bacteria involved in cheese fermentation have a significant impact on the final product's taste, consistency, and overall sensory experience.

The importance of temperature regulation

Temperature regulation is a critical aspect of cheese fermentation, playing a pivotal role in the development of flavour, texture, and overall quality. The importance of temperature control is underscored by the fact that advanced cheese-making ventures beyond simple cheeses like labneh or queso blanco and requires specialised equipment for temperature regulation.

The significance of temperature regulation in cheese fermentation is twofold. Firstly, it directly impacts the activity of the bacteria and enzymes involved in the process. Different strains of bacteria have specific temperature requirements for optimal growth and metabolic activity. For instance, mesophilic cultures thrive at temperatures of 90°F (32°C), while thermophilic cultures favour slightly higher temperatures of 91.5°F (33°C). By maintaining the desired temperature, the bacteria efficiently convert lactose to lactic acid, influencing the flavour and acidity of the cheese.

Secondly, temperature regulation is crucial for managing the coagulation and separation of milk curds and whey. The milk proteins coagulate at specific temperatures, and any deviation can hinder this process. For example, in the production of Cheddar and other English cheeses, the milk is cooled to a precise range of 29-31°C, facilitating the action of the starter organisms and the subsequent separation of curds and whey.

The temperature also influences the texture and consistency of the final product. Firmness and moisture content are regulated by temperature during the curd formation and whey expulsion stages. Additionally, temperature impacts the rate of bacterial growth and enzyme activity, which, in turn, affects the rate of flavour development during ripening.

Moreover, temperature regulation is essential for food safety. Maintaining the appropriate temperature prevents the growth of undesirable bacteria and other pathogens, ensuring that the final product is safe for consumption.

In summary, temperature regulation is of paramount importance in cheese fermentation. It ensures the desired bacterial growth, metabolic activity, curd formation, and flavour development, while also contributing to food safety and overall quality. Precise temperature control is, therefore, a key factor in crafting cheeses with distinct characteristics and ensuring their suitability for consumption.

The different methods for aging hard cheese

The aging or ripening of cheese is a crucial step in the cheese-making process, as it significantly influences the final product's taste, texture, and aroma. Hard cheeses need to be aged for at least a month, and usually for 4-6 months, to fully develop their flavor.

Cave Aging

Caves provide consistent temperature and humidity, which are essential for optimal aging conditions. The ideal temperature range is between 45-55°F (10-15°C), and humidity levels should be maintained between 75-95% RH. A cold room, cellar, or garage can also be used to age cheese, and a bar fridge or wine cooler can help maintain the correct temperature.

Waxing a Wheel of Cheese

Wax is the traditional rind for many types of cheese, including cheddar and Gouda. After pressing, the cheese wheel is allowed to dry out at room temperature for 2-4 days. Then, the cheese is coated with cheese wax (not beeswax) heated to 240°F / 115°C, which is hot enough to kill any mold or bacterial spores. The waxed cheese is then placed in the cave to age, and it is turned over daily for the first month and then weekly for the remaining aging period.

Bandaging a Wheel of Cheese

Bandaging a wheel of cheese involves wrapping it in butter muslin immediately after pressing, without letting it dry out. The cheese is rubbed with a layer of lard or butter and then wrapped in one or two layers of muslin. The cheese is then placed on a cheese mat in the cave and turned daily for the first month and then weekly after that. Various molds will grow on the outside of the bandage, adding to the flavor and protecting the cheese from drying out.

Washed-Rind Technique

The washed-rind technique involves washing the cheese wheel with brine or alcohol during aging to develop specific flavors and textures. After pressing, the cheese wheel is placed in a salt brine for 24 hours. It is then removed, patted dry, and placed in the cave to age. The cheese is turned daily for the first month and then once a week after that. Every three days, the cheese is wiped down with the brine solution to keep it moist and encourage the right type of bacteria to grow.

Affinage in Wrapping

This technique involves wrapping the cheese in specific materials such as leaves or cloth during aging to impart unique flavors.

Frequently asked questions