Cheese comes in an incredible variety of textures, flavors, and aromas, offering something for everyone. From soft and spreadable to hard and crumbly, mild and creamy to sharp and tangy, the possibilities are endless. This vast variety allows it to be incorporated into countless dishes, snacks, and desserts. Its creamy texture and rich flavor make it a staple ingredient in countless dishes.

Cheesemaking has been practiced for thousands of years and has become deeply ingrained in the cultural fabric of many societies. From France’s iconic cheeses to Mexico’s queso fresco, each region has its own unique traditions and methods for making this dairy product. As cheese production became more industrialized, cheese makers sought ways to improve the texture, consistency, and shelf life of their products. One way to achieve this is to add various ingredients in the dairy product. And one particular ingredient that makes better cheese is sodium citrate.

WHAT IS SODIUM CITRATE?

Sodium citrate, scientifically known as trisodium citrate, is a sodium salt of citric acid. It has a chemical structure consisting of three sodium ions (Na+) bound to a citrate molecule.

The citrate molecule, in turn, comprises three carboxylic acid groups (-COOH) attached to a central carbon atom, along with three hydroxyl groups (-OH).

This molecular arrangement imparts sodium citrate with its characteristic acidic properties and ability to chelate metal ions.

The production of sodium citrate typically involves a chemical reaction between citric acid and sodium carbonate or sodium bicarbonate. This reaction results in the formation of sodium citrate, along with the release of carbon dioxide gas and water. The reaction equation can be represented as follows:

Citric acid + Sodium carbonate (or Sodium bicarbonate) → Sodium citrate + Carbon dioxide + Water

This reaction is usually conducted in an aqueous solution under controlled conditions of temperature and pH (acidity). This optimizes the yield and purity of the sodium citrate product. After the reaction, the resulting sodium citrate solution may undergo purification steps, such as filtration or crystallization, to remove impurities and obtain the desired product.

Sodium citrate, acknowledged as a safe substance and generally recognized as safe (GRAS) by the Food and Drug Administration (FDA), serves multiple functions in the food industry, including as an acidity regulator, emulsifier, and preservative. Its emulsifying attributes render it particularly beneficial in cheese production, where it aids in enhancing texture and stability. According to FDA guidelines, emulsifying agents like phosphates, citrates (such as sodium citrate), and tartrates may be utilized in small quantities (less than 3% of weight) in pasteurized process cheese to achieve desired properties.

Let’s discuss this further.

FUNCTIONS OF SODIUM CITRATE IN CHEESE

Sodium citrate is frequently present in processed cheeses as opposed to natural or artisanal varieties, with processed cheeses being those that undergo modification and blending with other ingredients to enhance their texture, extend shelf life, and improve melting properties. Examples of such cheeses include Velveeta, cheese spreads, and American processed cheese.

Emulsification

Emulsification involves uniformly dispersing fat molecules throughout a water-based medium to create a stable mixture known as an emulsion, achieved with the assistance of emulsifying agents like sodium citrate. In cheese production, fat molecules tend to clump together naturally, resulting in uneven texture or separation of fats and liquids. Sodium citrate intervenes by stabilizing the emulsion, addressing these undesirable outcomes.

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The mechanism behind sodium citrate’s emulsifying property lies in its ability to interact with calcium ions. These ions play a significant role in the coagulation of milk proteins during cheese making. When sodium citrate binds with calcium ions, it disrupts the calcium-mediated interactions between protein molecules, thereby reducing their tendency to coagulate and facilitating the dispersion of fat molecules within the aqueous phase of the cheese. The result of this is even fat distribution throughout the cheese matrix.

Furthermore, sodium citrate’s emulsifying action extends beyond simply preventing fat separation. It also contributes to the creation of a smooth, homogeneous texture in the final cheese product.

Improving meltability

Sodium citrate significantly improves the meltability of cheese through its chelating properties. This positively affects the interactions between calcium ions and casein proteins. In cheese, calcium ions typically bind with the carboxyl groups of casein proteins. This contributes to the formation of a protein network that gives cheese its structure. However, this network can impede the smooth flow of fat molecules during the melting process. Most of the time, this results in an uneven texture and inconsistent melt.

Sodium citrate prevents this from occurring by forming complexes with calcium ions present in cheese. By sequestering these calcium ions, sodium citrate disrupts the interactions between calcium ions and casein proteins. This disruption weakens the protein network, allowing for greater mobility of fat molecules within the cheese matrix.

Improved meltability occurs as a result of this loosening of the protein network. With fewer hindrances, fat molecules can move more freely when subjected to heat, leading to a smoother and more consistent melt. Instead of clumping together or remaining trapped within the protein matrix, the fat molecules flow evenly, resulting in a velvety texture and enhanced mouthfeel.

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Moreover, sodium citrate’s chelating action helps prevent the formation of gritty or grainy textures that can sometimes occur during the melting process.

Many cheese spreads and dips, particularly those available commercially, contain sodium citrate to improve their meltability and texture. Sodium citrate helps these products achieve a smooth, creamy consistency that is ideal for spreading on crackers, dipping with vegetables, or using as a topping.

The post Why Sodium Citrate Makes Good Cheese appeared first on The Food Untold.

Cheese is primarily made from milk, specifically the milk of cows, goats, sheep, or buffalo. The milk is typically coagulated or curdled, which causes it to separate into solid curds and liquid whey. The curds are then processed and transformed into cheese through various methods, depending on the type of cheese being produced.

Now if cheese is primarily made from milk, which is white in color, why is cheese yellow, then?

Well, most cheese, in general, is yellow because of natural pigments called carotenoids.

The main providers of milk for cheese production are cows, and their diet typically consists of grass, hay, or silage. These feed sources contain carotenoids, specifically beta-carotene, which acts as a precursor to vitamin A and contributes to an orange-yellow hue in cheese.

During digestion, cows convert beta-carotene into vitamin A, which then gets stored in their body fat. When milk is produced, the fat globules carry some of these fat-soluble pigments, including the yellow-orange carotenoids, into the milk.

Let’s discuss further.

WHAT ARE CAROTENOIDS?

Carotenoids are a group of naturally occurring pigments found in various plants, algae, and some bacteria. They are responsible for the vibrant red, orange, and yellow colors seen in fruits, vegetables, and other natural substances. Carotenoids play important roles in both photosynthesis and the diet of organisms.

Structurally, carotenoids consist of a series of conjugated double bonds and are classified into two major groups: carotenes and xanthophylls. Carotenes are hydrocarbons, while xanthophylls have oxygen-containing functional groups. Common carotenoids include beta-carotene, lycopene, lutein, and zeaxanthin.

In milk, the most prominent carotenoid in milk is beta-carotene, which is primarily found in the milk fat globules. Beta-carotene is a precursor to vitamin A and is widely present in various fruits, vegetables, and other natural sources.

One of the primary functions of carotenoids in plants is their involvement in photosynthesis. They act as accessory pigments, capturing light energy that chlorophyll alone cannot absorb. By absorbing light across a broader range of wavelengths, carotenoids help optimize the energy-harvesting efficiency of plants.

Carotenoids also serve as antioxidants, protecting plants from the damaging effects of excessive light and reactive oxygen species. They help neutralize free radicals and prevent oxidative stress, which can cause cell damage and contribute to aging and disease.

WHITE MILK TO YELLOW CHEESE

Carotenoids end up in milk through the diet of the animals producing the milk. Carotenoids are naturally present in various plants, particularly in green, leafy vegetables and fruits. This is why grass-based silage contains more carotenoids than hay. When a cow consumes these carotenoid-rich plants, the carotenoids are absorbed into its bloodstream.

Once absorbed, carotenoids are then transported to various tissues and organs, including the mammary glands, where milk production takes place.

During the cheese-making process, the carotenoids become more concentrated and visible. Here’s how.

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When the milk is coagulated using rennet or bacterial cultures, the curds separate from the liquid whey. Within the curds, the fats and proteins encapsulate the carotenoids. These carotenoids are initially dispersed throughout the milk, but as the curds form, they become more concentrated within the solid portion.

The next crucial step is draining the whey from the curds. As the whey is removed, the remaining curds become denser and more concentrated. Consequently, the carotenoids, including beta-carotene, which is a prominent yellow-orange pigment, become more pronounced and visible within the curds.

Additionally, as the curds are processed further, such as through heating, cutting, and pressing, the concentration of carotenoids continues to increase. The manipulation of the curds during these stages aids in expelling excess whey, compacting the curds, and consolidating the cheese. The increased concentration of carotenoids intensifies the yellow color of the cheese. The yellow color is more intense if the milk was obtained from a cow that graze on fresh silage.

WHAT’S WITH WHITE AND ORANGE CHEESES?

While the majority of cheeses are naturally yellow, some are white or orange in color.

Certain orange-colored cheeses are mostly owing to the addition of annatto, a natural food coloring. Annatto is obtained from the seeds of the achiote tree, and is widely used to provide an orange tint to cheese. The amount of annatto used determines the intensity of the orange color. Some cheeses that are orange in color are:

• Red Leicester: Red Leicester is a British cheese that is typically made with cow’s milk. It has a firm texture and a nutty, mellow flavor.
• Colby: Colby cheese is a semi-hard American cheese that is slightly milder than cheddar. It is often used in sandwiches, snacks, and grated over dishes.
• Gloucester: Gloucester cheese is a traditional English cheese that comes in two varieties: Single Gloucester and Double Gloucester. It has a mild, creamy flavor.

Certain cheeses, such as cottage cheese and feta, maintain their white appearance due to their higher acidity levels. These cheeses possess dense protein structures. This denser protein network prevents the absorption or retention of colorants or pigments that might be present in the milk. For this reason, they maintain their original white appearance.

Another reason for the whiteness of certain cheeses is the type of milk used. Cheeses made from the milk of animals like goats and water buffalo, such as goat cheese and buffalo mozzarella, exhibit a white coloration. This is because these animals do not store beta carotene in their fat. Instead, they convert beta carotene into colorless vitamin A. As a result, the cheeses produced from their milk do not acquire a yellow color.

The post Food Science: Why Is Cheese Yellow? appeared first on The Food Untold.

When talking about cheeses, most people think about cheddar, Swiss, American, mozzarella, or Parmesan cheese. These types of cheese have one thing in common—they taste and smell good. So there is no wonder why they are the most commonly eaten. In the United States, the most popular cheese is Cheddar, according to a poll conducted by Yougov. 1 for every 5 Americans or 19% prefer the cheese that originated from Somerset, England. Came in 2nd at 13% preference is Uncle Sam’s own American cheese, and 3rd (9%) is mozzarella cheese, which was followed closely by Swiss cheese (8%).

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Now where is the Limburger cheese? Is it surprising? Limburger, Muster, and other similar cheese types are known for their undesirable smell, to many, at least. This pronounced stench that Limburger cheese gives off is because of a certain bacteria involved during the ripening process.

Well, aged cheeses involve certain microorganisms during the ripening process that provide the distinct characteristics of the final product. Take the Swiss cheese for example. The production of Swiss cheese involve cultures of Propionibacterium shermanii. During cheese ripening, the propionibacteria consume the lactic acid of cheese to produce acetic and propionic acid. Along with the acid is carbon dioxide, the gas responsible for the characteristic eyes of Swiss cheese.

In the case of Limburger cheese, the bacteria responsible for the pungent smell are Brevibacterium linens. Although the bacteria make the cheese smell like rotting, they would not make anyone feel ill. An aversion to the odor of rotting has the apparent biological benefit of keeping us safe from food illness. So it is no surprise that a food made from an animal that smells like shoes or soil takes some getting used to.

BREVIBACTERIA IN LIMBURGER CHEESE

The surface growth of B. Linens are a necessary condition for the creation of the distinctive color, flavor, and aroma of smear surface-ripened cheeses, Limburger cheese particularly. Brevibacteria are smear bacteria that are natives of salty environment (up to 15% salt concentrations). These salty conditions inhibit the growth of most other microorganisms. Brevibacteria also grow in warmer conditions, and grow optimally at temperatures between 68°F (20°C) and 86°F (30°C). However, they do not withstand acidic environments well, unlike most finishing bacteria. They grow well at neutral pH and pH between 6.5 to 8.5.

When used for producing Limburger cheese, one key point cheese makers have to know is that the bacteria are an obligate aerobic bacteria—they require oxygen to grow. For this reason, the bacteria are introduced into the cheese during the ripening process by wiping it with a salt brine. This is unlike cheeses that are ripened by lactic acid bacteria, which are nonaerobic or aerotolerant microorganisms.

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The presence of Brevibacteria at the surface lead to excessive lipolysis and proteolysis. Lipolysis is the breakdown of lipids and fats, producing fatty acids, whereas as proteolysis is the breakdown of proteins.

HOW BREVIBACTERIUM LINENS PRODUCE THE SMELL

The breakdown of fats and proteins on the surface is what makes Limburger cheese distinct from most cheeses. Lipolysis and proteolysis form several carboxylic acids, such as volatile 3‐methylbutanoic, butanoic, and hexanoic acids. These acids give off aromas which are very similar to those of sweaty feet or gym socks smell.

The reason for this is because another Brevibacteria habitat of these bacteria is the human skin. And if you are wondering, they are the same bacteria responsible for body and foot odor. Our feet, when salty, sweaty, and moist just become the perfect place for them to thrive.

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It is said that the human skin is most likely the original source of the culture. Well, yes, it is possible that a cheese maker ate a cheese after growing it in a salty, warm, and oxygenated environment. This was probably how the bacteria were transferred from skin to cheese. Besides, this was how most foods we consume today started.

Other aroma molecules responsible for the smell of Limburger cheese include methanethiol and methyl thioacetate. Methanethiol is a very volatile molecule with a characteristic odor that is characterized as or “rotten egg-like” or”cabbage-like”.

The post The Bacteria That Make Limburger Cheese Smell appeared first on The Food Untold.

There are many varieties of cheese around the world but the process is similar.

After the milk passes quality and purity tests, it is standardized and pasteurized. Standardization makes the milk consistent, adjusting the protein and fat ratio. Pasteurization destroys potentially harmful bacteria in the milk. Then good bacteria or starter culture is added. Starter culture ferment lactose (milk sugar) to produce lactic acid. The type of bacteria depends on the type of cheese to produce. Streptococcus thermophilus and Lactobacillus helveticus, and propionic acid bacteria are common starter cultures in Swiss cheese. Aside from starter culture, few other ingredients may be added.

Coagulation is the first step in turning the milk into solid cheese. Lactic acid from starter cultures is what causes fresh cheese to coagulate. Mature cheese is curdled by adding an enzyme called chymosin, which is present in rennet. The resulting solid mass after coagulation is called “gel”, “curd”, or the “coagulum”. This is cut to allow the whey (liquid) to come out. The size of the cut depends on the type of cheese. Small curds produce drier cheese since more moisture is released. Stirring and heating release more whey.

After cooking, the curd is salted and pressed in a form (Cheddar and Colby), or in a hoop (mozzarella and Swiss cheese). The majority of soft cheeses are not mechanically pressed, whereas the majority of semi-hard to hard cheeses are. Pressing closes the texture, promotes curd fusion, and helps extract more whey.

After pressing, the cheese is ripened. The duration depends on the type of cheese, and the target quality. Typically, cheese ripening ranges from 2 weeks to several years. However, there are cheeses that do not undergo ripening, which include cottage, cream cheese, ricotta, and feta cheese.

Here is what happens during ripening.

HOW IT IS DONE

The cheese is transformed into a delicious cheese during the ripening process over the course of two weeks (for mozzarella) to two or more years by the starter bacteria (still present) and additional bacteria (referred to as the finishing or ripening bacteria) and their corresponding enzymes (Cheddars and Parmesans).

There are also cheeses that are ripened with mold. For example, Camembert and Brie cheese is sprayed with mold onto the surface. Blue cheese is ripened by introducing Penicillium roqueforti internally.

Since microorganisms are involved during ripening, temperature and humidity control is important as it eventually impacts the resulting flavor, texture, and aroma of the cheese. Most cheeses are ripened in cheese-ripening cellars or special storage rooms. Ripening cellars imitate the conditions of a cave. The humidity and temperature are particularly well monitored, depending on the type of cheese.

However, most cheeses are ripened between 46° (8°C) and 60°F (0°C), with a relative humidity of 85–95%. The cellar’s climate is regulated by the air flow, humidity, and temperature in the surrounding area.

Affinage, which translates in French as “end” or “final point,” is the word for ripening. An affineur, cheese tenderer, or finisher may occasionally complete this stage of the cheese-making process. Until the cheese has sufficiently aged to be packaged and sold, the affineur takes care of the cheeses. The affineur periodically rubs, washes, brushes, or sprinkle the surfaces of the cheeses with salt brine and ripening bacteria as they ripen. Every cheese needs to be turned regularly to guarantee even bacterial growth and to avoid cheese shape abnormalities. The cheese’s appearance, aroma, taste, and texture are also evaluated by the affineur to determine when it is ready to be packed for sale.

THE CHEMISTRY OF RIPENING

During the cheese ripening (affinage) process, several chemical and physical changes take place that lead to texture, flavor, aroma, and color development. The changes include the degradation of the following molecules:

• Lactose to lactic acid through fermentation
• Fat by lipase through hydrolysis
• Protein to amino acids by rennin through mild proteolysis.

The bacteria that are present during the cheese-making process of ripening, as well as the type of milk utilized, determine the aromatic, flavorful, distinct molecules that are created. Let’s discuss each further.

Lactose

Lactose is the milk sugar found in all dairy products, including cheese. During ripening, lactose is converted into lactic acid, turning the milk acidic. This is the main reaction that occurs during maturation or ripening. Additionally, the starting culture directly affects flavor development through the generation of metabolites and enzymes. Cheesemakers have two options for starting the fermentation process: either they can buy starter cultures made in factories, or they can rely on the bacteria found in raw milk naturally. Acid and taste development is typically more reproducible when industrial starter cultures are used.

As some of the lactic acid bacteria (LAB) start to die, cells release enzymes that further break down milk proteins, particularly casein, into tiny peptides and amino acids. These dead starter culture cells serve as a vital source of food for non-starter lactic acid bacteria. The starter culture must die in order for the cheese to grow.

Aside from the conversion of lactose to lactic acid, another result of bacterial fermentation is the formation of characteristic holes in some cheeses. Propionibacteria—the propionibacteria shermanii is a significant bacterium in Swiss starting cultures and is well-known for its ability to create holes. Like most bacteria, this one starts out as the starter culture for the cheese and continues to absorb lactic acid during the rennet process and while the cheese is ripening. This process continues throughout the ripening stage, converting the lactic acid into a mixture of propionic and acetic acids as well as carbon dioxide gas, which is what gives Emmentaler cheese its distinctive holes. For more about microbes in cheese: this FAQ page should help.

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Lipids/fats

Cheese’s flavor and texture are greatly influenced by fats. In fact, the same ripening enzymes that break down proteins also break down and chemically alter lipids to create a symphony of aromatic and tasty chemicals. In the curd, lipases (enzymes that break down lipids) convert milk fat’s triacylglycerol fats into free fatty acids.

The fatty acids then go through another chemistry involving oxidation and reduction. The fatty acid is oxidized at the carbon that is “beta” to the carboxylic acid during beta-oxidation. This enables a decarboxylation reaction, which shortens the chain of fatty acids by two carbons and produces a ketone or alcohol. In delta-oxidation, a carbon atom that is four units distant from the carboxylic acid is added to produce a δ-hydroxyacid. These substances are capable of cycling into a lactone.

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An ester can also be created from the fatty acid. This chemistry is important because some short fatty acids possess a taste or aroma that is peppery, sheep-like, or goat-like

Protein (casein)

The primary protein in cheese, casein, is hydrolyzed in a manner and at a rate specific to each variety of cheese. The specificity of the enzymes present is related to the variety of peptides of different compositions that are produced by proteolytic enzymes. Amino acids are produced by further hydrolysis.

The amino acids themselves have a variety of savory and sweet flavors. For instance, the amino acids alanine and tryptophan have sweet and bitter tastes, respectively, while cysteine and methionine, which contain sulfur, give food a “meaty” or “eggy” flavor. Savory recipes frequently contain the amino acid glutamate, also known as MSG, to improve flavor. All of these amino acids are created during casein degradation and have an impact on cheese flavor.

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Many of these amino acids will be further broken down into smaller amines, such as trimethylamine (which tastes fishy), putrescine (which smells like rotting meat), or ammonia, while some amino acids will remain in that molecular state. Despite the fact that these flavors sound awful in this context, a certain cheese with a modest amount of them has a complex, rich, and distinctive flavor.

Since skim milk cheese never develops the full aroma of regular cheese, lipid breakdown is crucial for the formation of cheese aroma.

References

M. Gibson (2018). Food Science and the Culinary Arts. Academic Press.

V. Vaclavik, E. Christian (2014). Essentials of Food Science (4th edition). Springer.

J. DeMan, J. Finley, W. Jeffrey Hurst, C. Y. Lee (2018). Principles of Food Chemistry (4th edition). Springer.

M. Wallert, K. Colabroy, B. Kelly, J. Provost (2016). The Science of Cooking: Understanding the Biology and Chemistry Behind Food and Cooking. John Wiley & Sons, Inc.

The post The Chemistry of Cheese Ripening appeared first on The Food Untold.

Colby cheese is a type of hard cheese produced from cow’s milk. It originated in 1885 in the town of Colby in Wisconsin, hence the name. Because of its mild taste, Colby cheese is not ideal for cooking. However, it is a great choice for pizza, sandwiches, salads, mac and cheese, burgers, and cheese sauce.

According to the Food and Drug Administration (FDA), Colby cheese is made with or without artificial coloring, contains added common salt, includes no more than 40% moisture, and comprises at least 50% milkfat in its total solids content.

COLBY CHEESE VS CHEDDAR CHEESE

Colby cheese is very similar to Cheddar cheese because of its yellow color. Both cheeses are also dyed with annatto, an orange-red food coloring agent produced from the seeds of achiota tree. However, there are several distinct features between the two. Colby cheese is more moist, softer, and milder than Cheddar cheese.

The process of making Colby cheese is similar to those of other cheeses, including Cheddar. There is acidification of milk, the addition of rennet, and separation of curds from whey. But there is a modification to the process—washing of curds with cold water. In this step, the whey is replaced with water (washed-curd process). This interrupts the acidification process leading to a cheese that is what Colby cheese is known for—moist, soft, and mild.

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There are three types of Colby cheese. First is the regular Colby cheese in rectangular block shape. Second is the traditional Longhorn Colby, which is cylindrical in shape. This is cut into wheels, and then cut into halves to form semi-circle portions. The reason why it is called Longhorn is that the moon-shaped semi-circle looks like the horns of cattle. The last type of Colby cheese is a marbled cheese called “Colby-Jack”, which is a combination of Colby and Monterey Jack cheese. To produce this marbling effect, curds of Colby cheese and Monterey Jack are mixed right before the pressing and ripening stage.

Let’s discuss further.

INGREDIENTS

There are 5 basic ingredients in producing Colby cheese: whole cow’s milk, bacterial culture, calcium chloride, rennet, and annatto (optional).

Whole cow’s milk

Most kinds of milk are good for making cheese—raw milk or pasteurized milk. But not ultrapasteurized milk. Ultrapasteurized milk has undergone a heat treatment of 284°F (140°C). This process eliminates almost all of the microorganisms in milk. However, this denatures too many of the milk proteins. As a result, the calcium does not bond well to produce a good curd necessary for making Colby cheese.

Bacterial culture

Most bacterial starter culture for making cheese are mesophilic, microorganisms that can tolerate moderate heat. The function of bacterial starter culture is to turn the milk acidic and denature the casein and other proteins for curdling.

In the case of Colby cheese, Lactococcus lactis ssp. cremoris and Lactococcus lactisssp. lactis form the most common mesophilic and homofermentative culture.

In many cheese making stores and websites, mesophilic culture starter bacteria can be purchased. Most of them are a mixture of strains of lactic acid producing bacteria. While other culture strains may be used, they may produce other compounds and more acid.

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Calcium chloride

Calcium chloride is not harmful. It is generally recognized as safe (GRAS) as per FDA. It should not exceed 0.2% in cheese as per current good manufacturing practices. The benefit of calcium chloride is that it increases the amount of acidity and adds calcium ions that hold the proteins together. This helps the milk to coagulate better and increase curd yield. If the milk is low in calcium ions, it will have a harder time to facilitate coagulation. Hence, this ingredient is especially helpful when the milk is low in milk solids or overheated.

Rennet

Rennet is a form of an enzyme that acts on casein protein and finishes the curdling process. It comes in two forms: from animal stomach (calf or sheep) or vegetable (thistle). This enzyme breaks down a particular peptide link in the milk protein in a very specific manner. The milk proteins aggregate and form curds as a result of this hydrolysis.

Rennet keeps its function as a proteolytic agent during cheese ripening, in addition to the bacterial starter culture and natural enzymes in the milk. Their combined action produces the texture and flavor profile of Colby cheese.

Annatto

Annatto is an optional ingredient in Colby cheese. It is a food dye derived from Achiota tree seeds. It is used to impart the distinct orange color of Colby cheese. White Colby is made without annatto. Cows that graze in grassy fields produce milk with yellow colored carotenoids. However, the natural annatto dye has been more used as most cows feed on silage, instead of fresh grass.

MAKING COLBY CHEESE

The process of making Colby cheese is similar to that of Cheddar but without “cheddaring” , wherein the curd is cut into cubes to drain the whey before stacking.

It starts by heating the milk at 86°F (30°C) and then adding calcium chloride and annatto dye. The bacterial starter culture is then added. The elevated temperature of 86°F is maintained for 1 hour as the culture becomes active and ferment. Rennet is added to the mixture and then stirred. The mixture is allowed to sit for 45 minutes while moderately lowering the heat. After 15 minutes, there should be a slight firming of the mixture, which can be tested by lightly pressing with a sterile spoon. The cheese is then allowed to sit for 30 or more minutes or until a clean break is observed.

A clean break happens when the milk has curdled and the solid milk breaks cleanly after scooping it with a finger or tool upward. The color to look for is clear and yellow. It is not yet ready if it is milky white or cloudy.

Using a sterile spatula, the curd is cut into 1 inch cubes. This way, the whey separates in the space. Next, the cheese is slowly heated at 103°F (39°C) for 30 minutes or until curds have harden. The curds are ready once they are mostly solid and firm throughout. If the curds have moderate resistance, when pressed using fingers, this means most of the moisture has already been removed. The curds are then incubated at this temperature for 3 hours.

Washed-curd process

After incubation, washing the curds removes the lactose in the whey. The temperature of the curds is lowered to 70°F (21°C) by slowly adding cool water while stirring gently for 15 minutes. This will also slow down the rate of bacterial fermentation. Raising this temperature may produce less moist Colby cheese.

After that, the curds are transferred to a mold using cheese cloth and then drained. Pressing the mold with 20 to 50 lbs (depends on the mass and size of cheese) produces a more cohesive cheese while eliminating moisture. Presses can be a homemade weights or a commercial hydraulic press.

Then, the cheese is bathed in brine of salt and calcium chloride to dehydrate to Colby cheese further. The cheese is waxed to regulate the reaction of oxygen with proteins and fats. This also allows the bacteria to consume the remaining proteins, sugars, and fats as the cheese produces aroma and flavor compounds as it matures. Colby cheese ripening can take anywhere between 5 weeks to 3 months at 37°F (3°C) to 39°F (4°C).

The post What Is Colby Cheese? How Is It Made? appeared first on The Food Untold.

Cheeses come in various shapes, texture, color, and taste. Perhaps, the most iconic among these cheeses is Emmental or Swiss cheese because of its distinct holes (called “eyes” as well). Well, during its early days, the holes of Swiss cheese were not intended to be there. In fact, cheese makers did not want them in their product.

But studies have proven that these holes can be used as an indication of the cheese’s quality and maturity. In fact, quality control of Swiss cheese making also includes the inspection of the formation of holes. Without these eyes, cheesemakers would call the cheese “blind”. Fortunately, the size of the holes can be controlled with proper acidity, temperature, and length of storage.

But why does Swiss cheese have holes? Have you ever wondered about this?

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To answer this question, let’s take a look at how Swiss cheese is made.

MAKING SWISS CHEESE

One of the first steps in Swiss cheese making is creating curds from milk. Like most hard cheeses, rennet, a proteolytic enzyme can be used to form curd for Swiss cheese. Rennet acts by breaking down a particular peptide link in milk protein. The milk coagulates to produce curds as a result of the hydrolysis reaction.

Lactic acid bacteria also aids in curdling the milk, resulting in a gelatinous-like substance.

After curdling, an equipment called harp is used to cut the curd into pieces. This separates the whey from the curds. The size of the pieces determines the texture of the final cheese. To remove more whey, the curds are heated to about 125°F (52°C). The temperature depends on the texture of the final product. The higher the temperature, the harder the cheese.

The curds remaining are then molded into wheels. The molds are perforated to allow the remaining whey to drain. Traditionally, the cheese is pressed multiple times allowed to stand overnight. Modern Swiss cheese making involves using a hydraulic press to press the molds for 20 hours.

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Pressing cheese removes any remaining moisture from the curd. It also enhances the final texture, resulting in a firm rind on the outside and a smooth finish inside. The cheese is pressed into the customary wheel shape and prepared for aging.

After pressing, the cheese is placed and soaked in a brine bath. Soaking in brine lasts for several hours up to 48 hours. The high salt content of the brine helps removes the remaining whey. And as the cheese absorbs salt, it solidifies and cheese rind forms. The salt adds flavor to the cheese. And more importantly, the salt brine inhibits the growth of unwanted microorganisms.

MATURATION AND HOLE FORMATION

Then, the cheese is moved to a fermentation cellar. Inside this cellar, the cheese allows to sweat and is turned regularly. Afterwards, the cheese is transferred to another cellar, where the temperature is cooler (around 53°F). This particular cellar possesses conditions that allow the favorable physical, chemical, and microbiological changes in the cheese to take place. Cheese maturation, also called affinage, lasts for several days, months, or even years, depending on the cheese.

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During maturation of Swiss cheese, the changes that take place include the development of texture, flavor, aroma, and color. Visually, Swiss cheese is distinct because of the holes. And no, mice do not eat the cheese.

In cheese production, two strains of bacteria may be used. The first one is a starter bacteria, which is responsible for the production of lactic acid bacteria. The second is the non-starter bacteria (or ripening bacteria). The finishing bacteria depends on the type of cheese. In the case of Swiss cheese, Propionibacterium shermanii is an important bacterium in Swiss cheese culture as it is responsible for the formation of holes.

During ripening, propionibacteria consumes the lactic acid in cheese, producing a mixture of propionic, acetic acid, and carbon dioxide gas. Due to the gathering of carbon dioxide at weak places inside the curd, holes or eyes are created. The holes of Swiss cheese vary in size, from medium to large (1 to 3 cm). To better control hole formation, a culture of selected propionibacteria is used for a more controlled propionic acid fermentation. Spontaneous fermentation only leads to irregular hole formation, and splits and cracks are more likely to occur.

Other types of bacteria used in Swiss cheese are Lactobacillus and Streptococcus salivarius subspecies. A common characteristic of finishing bacteria is they flourish in lower, acidic pH environments established by starting cultures. Many of these bacterial strains can withstand the higher temperatures required to finish the cheese making process.

Another benefit of finishing bacteria is they produce other flavors as they consume fat, protein, and sugar. For example, milk fats are damaged in the copper cauldrons, and the freed fatty acids are converted to esters and lactones with pineapple and coconut scents.

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There are some types of cheeses that get better with age, just like wine. The maturation period varies, from several weeks to years. Mozzarella cheese is ripened for 2 weeks. Parmesan and cheddar cheese are ripened for 2 or more years. While some cheeses, particularly those from Europe, take longer, like Bitto Storico for example. This cheese from Italy may reach its best quality in 18 years. Typically, cheese makers age cheese in a ripening cellar or a room where the conditions support the ripening process such as controlled humidity and temperature. During aging, three components in the cheese degrade, namely casein, lipids or fats, and lactose. This leads to the formation of flavorful aroma molecules that are distinct to aged cheeses. The flavor profile of the cheese depends largely on the microbes involved and how the fat in the milk was broken down.

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When cheese production in North America and Europe reached industrial scale, cheese became more popular, undoubtedly. But when exporting of cheese began in the late 19th century, exporters saw one big problem during the transport— how to keep cheese from spoiling fast. Deterioration of cheese was more frequent during transport to distant areas. To address the predicament, a new type of cheese that is more shelf life stable had to be created. And it turned into fruition in the formed of processed cheese.

WHAT IS PROCESSED CHEESE?

Natural cheeses are made basically with high quality milk, culture (lactic acid bacteria), enzyme (rennet), natural colors, and salt. They may or may not be ripened. Cheeses that are not aged, also called fresh cheese, are made with fresh curds.

These ingredients alone proved to be not enough for cheeses meant for sending to far places. The first attempt to making a cheese that is more resistant to spoiling was done in Germany in 1980.

But significant development came in 1911 when Walter Gerber and Fritz Stettler of Switzerland added citric acid salts to heated natural Emmentaler cheese. The product was a cheese that was less perishable and had better meltability. The Swiss called this cheese “Schachtelkase” (boxed cheese).

In 1915, a similar method was done in the United States. Canadian-American inventor James Craft added phosphoric acid salts to Cheddar cheese to improve its keeping quality. The result? A dairy product we now know as American processed cheese. In 1916, Kraft filed a patent for this process of pasteurizing and emulsifying cheese. This proved to be a major contribution in the food manufacturing industry. By 1930 in the US alone, a study revealed that more than 40% of the cheese consumed were Kraft’s.

Today, manufacturers use scrap unripened cheese as its basis for processed cheese. A mixture of cheeses of different maturity may be added. This is mixed with a mixture of emulsifying salts. These include sodium phosphate, sodium citrate, and sodium polyphosphate.

So yes. If the box says things like “cheese food,” “processed cheese,” or “prepared cheese,”, it is not all cheese.

PROCESSED CHEESE PRODUCTS

Like we already know, processed cheese is not 100% cheese. Typically, processed cheeses contain around 50% to 60% natural cheese. McDonald’s says their cheese slices in their burgers contain 60% real cheese. But this does not change the fact that the processed cheese industry is enjoying economic growth. This is due in large part of mass production that lowers the price of processed cheese. In fact, Statistica estimated the value of the processed cheese market at 16.3 billion US dollars worldwide in 2020. By 2029, the market is projected to reach 24 billion U.S. dollars.

Over the years, processed cheese manufacturers have used other ingredients in their product to appeal to a wider audience. This is the reason why we see processed cheeses of different flavors, textures, colors, and even shapes at the supermarket. Some processed cheeses come packed in cans, blocks, or individual slices wrapped in wax paper.

Here are the three main varieties of processed cheese.

Pasteurized process cheese

Pasteurized process cheese is the most commonly manufactured cheese in the United States. According to the Food And Drug Administration (FDA), pasteurized processed cheese is the food producing by comminuting, mixing, with the aid of heat, one or more cheeses of the same, or two or more varieties for manufacturing with an emulsifying agent . . . into a homogeneous plastic mass. The FDA excludes some varieties of cheeses such as cream cheese, cottage cheese, neufchatel cheese, cottage cheese, and low fat cottage cheese for producing pasteurized process cheese.

Meltability is one of the advantages of processed cheese over natural cheeses. The addition of an emulsifier such as sodium citrate or disodium phosphate allows the cheese to melt uniformly and smoothly during cooking. Emulsifiers do this by holding the protein and fat together. Unprocessed cheeses such as mozzarella and Cheddar tend to separate into molten protein gel and liquid fat during prolonged heating.

By standards, pasteurized process cheese contains not more 40% moisture by weight, not less than 30% fat, and has a pH (acidity) of not less than 5.3. The pH of most pasteurized process cheese in the market is 5.6 to 5.8.

Pasteurized process cheese may also contain an optional mold-inhibiting ingredient of not more than 0.2% by weight of sorbic acid, sodium sorbate, potassium sorbate or any combination or these.

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Some products contain fruits, vegetables, meat, and pimentos.

Pasteurized process cheese food

Pasteurized process cheese food is very similar to pasteurized process cheese in terms of ingredients and manufacturing process. Although there a few differences. Generally, pasteurized process cheese food contains more moisture, less fat, and has a lower pH.

By standards, pasteurized process cheese food contains at least 51% cheese by weight. It has a moisture content of not more than 44% by weight, fat content of not less than 23%, and has a pH of not less than 5.0. Organic acids such as lactic, citric, and phosphoric acid may be added to lower the pH.

An emulsifying agent may be added provided that the weight of the solids is not more than 3% of the weight of the pasteurized process cheese food.

Pasteurized process cheese food may contain optional ingredients such as non-fat dry milk, cream, non-fat milk, whey, and other coloring and flavoring agents.

In terms of quality, pasteurized process cheese food has a milder flavor, softer texture, and melts readily.

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Pasteurized process cheese spread

Pasteurized process cheese spread is also similar to pasteurized process cheese. But the main difference is that pasteurized process cheese spread contains more moisture in order to be more spreadable.

By standards, pasteurized process cheese spread contains at least 51% cheese by weight. In many standards, pasteurized process cheese spread must contain not more than 60% of moisture. In the US, the moisture content should be between 44% to 60% to be spreadable at 70 °F (21 °C). It should also contain not less than 20% fat and a pH of not less than 4.0.

For better water retention, binding agents such as gums and gelatin may be added in amounts not exceeding 0.8% of the weight of the finished product.

The US standards for these processed cheese varieties can be found here on Wiley.

Other references:

M. Wallert, K. Colabroy, B. Kelly, J. Provost (2016). The Science of Cooking: Understanding the Biology and Chemistry Behind Food and Cooking. John Wiley & Sons, Inc.

V. Vaclavik, E. Christian (2014) Essentials of Food Science (4th Edition). Springer

A. Gouda, A. Abou El-Nour (2003). Encyclopedia of Food Sciences and Nutrition (Second Edition). Academic Press.

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