Fine-Tuning the Art of Cheese Making

Picture the world without cheese and it's not a pleasant prospect. Pizza topping would stop with the tomato sauce. Macaroni would have to find a new plate buddy and grilled cheese sandwiches would be reduced to plain, white toast. And that just skims the surface. There are literally hundreds of cheese varieties, each with a unique personality and flavor profile, and endless application possibilities.

Cheese, like any properly crafted food, is a combination of art and science. However, while few frozen dinners inspire competition, hundreds of international representatives competed in the 2004 World Champion Cheese Competition hosted by the Wisconsin Cheese Makers Association in Madison, WI. This year, from among 1,312 entries from 19 countries, judges awarded the highest points and title of "world-champion cheese" to an Old Gouda produced by Meint Scheenstra, Frico Cheese Oosterwolde, Oosterwolde, the Netherlands.

Such titles are not for novices. For instance, Wisconsin is home to 32 Master Cheese Makers representing 24 cheese varieties. Administered by the Wisconsin Center for Dairy Research (WCDR) on the University of Wisconsin campus in Madison, and funded by the Wisconsin Milk Marketing Board (WMMB, also in Madison), the Master Cheese-Maker program was established in 1994 and is the most rigorous of its type outside Europe. Participants must be active, licensed Wisconsin cheese makers with at least 10 years experience and can only seek that title after making a particular cheese variety for at least five years. Participants must complete a total of seven courses and a three-year apprenticeship for each cheese for which the person requests certification.

As most cheese makers might attest, there is always room for improvement, however slight. Even the world-champion cheese achieved a score just shy of 100. When it comes to making a good cheese, production, yield and functionality all factor in with flavor and appearance.

Milk is the basic ingredient for any natural cheese. By far, the most common source in this country is cow's milk, but cheese can be and is made from sheep, goat and buffalo milk. The type of milk affects cheese flavor and functionality. For example, sheep's milk is high in total solids (averaging in the approximate range of 17% to 21%, depending on the sheep breed) and produces higher yield. Milk high in fat produces a softer cheese with a pleasant mouthfeel.

In addition to the milk, variations in either processing or ingredients yield the different types of cheese. For example, Cheddar and colby are similar, but Cheddar undergoes a distinctive processing step called "cheddaring" that mats the curd particles together into a cohesive mass. For a very basic primer, both the WMMB and California Milk Advisory Board, South San Francisco, offer short, online video tours demonstrating some cheese-making basics. (Visit www.realcaliforniacheese.com to view an online demonstration for making Monterey Jack.)

Boiled down to basic clinical steps, the cheese-making process goes something like this: mix the milk and starter cultures in a vat; add rennet and allow curds to form; once curds form, cut the curd into smaller pieces; cook and agitate the curds; drain off the whey; then salt, press, dry and age. Again, a volume of information coincides with each step and different cheese varieties require distinctive patterns of manufacture. And at any stage, alterations in the process can help create a different type of cheese, or influence yield and functionality. Yet manufacturers must adhere to strict FDA guidelines (21 CFR Pt. 133) governing cheese and cheese product identity.  

For example, the starter culture or bacteria added helps determine the end product or type of cheese made. Starter cultures added to the milk create lactic acid, essential for producing cheese. Some cheeses, such as Swiss, use a combination of starter cultures. Those distinctive holes result from Propionibacter shermani, one of the three types of bacteria reqiured to make Swiss. The cheese maker can control the size of the holes by changing the acidity, temperature and curing time, either making larger holes, or "eyes," or the smaller, lacy structure common to other types of cheeses.

As with most other aspects of cheese manufacture, even the holes have rules. USDA guidelines regulate the sizes of the holes within Swiss cheese and manufacturers that don't meet this guideline fail to receive a Grade-A designation.

Larger production facilities might have 40,000-lb. vats to produce cheese the conventional way. But a researcher at Cornell University, Ithaca, NY, is proposing a vatless cheese-manufacturing method instead of a continuous filtration and coagulation system. He says this could save space and money, in addition to producing a more-consistent cheese and a pure whey stream.

Production ratios in conventional manufacturing methods begin with 100 lbs. of milk to produce 10 lbs. of cheese and the resulting 90 lbs. of whey. Syed Rizvi, Ph.D., Cornell Institute of Food Science, is working on a project funded by Dairy Management Inc.(TM) (DMI), Rosemont, IL, and other dairy industry groups that would turn the process around, taking the whey out before starting manufacture. "The whey stream would be free of the colorants, bacteria, enzymes, etc.," he says, "and invariant of the type of cheese manufactured."

This, in turn, yields a casein-rich retentate. "The more you can concentrate, the more whey protein gets removed," says Rizvi. He indicates that with a concentration factor of eight, a large amount of the whey protein is removed from the stream, and the retentate is eight times reduced in volume. The small quantity of whey left in the system, says Rizvi, will be three- to four-times richer in glycomacropeptides (GMP) than regular whey, making their recovery more efficient. GMPs are finding increasing value as an ingredient in infant formulations.

This resulting retentate then becomes the basis for cheese manufacture. As an added bonus to the cheese processor, this concentrated system doesn't need as much rennet, an expensive ingredient that can be reduced by 75%.

The space savings, or continuous tank processing, is possible, says Rizvi, "Because once you remove 90% of volume of whey, you don't need larger vats."   He says this continuous method of manufacture does require some modifications to the make procedure to ensure a good-quality cheese, such as lowering the pH of the milk or increasing coagulation time for the reduced rennet to work on the curds before cutting. The hardware required is very different than that used in standard manufacture, and thus he could envision this method appealing to "new, beginning companies who might wish to get into the cheese-making business and do it with newer technologies."

While the continuous system or casein-rich retentate method of cheese manufacture is yet in the future, a few manufacturers are using a concentrated form of milk that lends them economies of scale.

According to the standard of identity, manufacturers cannot use filtered milk that has been spray-dried into a powder to produce natural cheese, but they can use filtered milk in its wet form. WCDR researchers (supported by DMI) conducted case studies on different cheese varieties using membrane-filtered milk for production, and then compared those cheeses to conventionally manufactured cheese to determine whether there were any quality differences. Membrane-filtered milk reduces the water or liquid by various concentrations, usually producing an end wet-milk product that is two- to three-times thicker than usual, and can be shipped more economically than regular milk. USDA has granted permission for use of filtered milk in mozzarella and Cheddar production, and some companies are using the technology for processing these higher-volume cheeses.

Using this type of milk in cheese production lends economies of scale to the process. It gives a better yield -- more milk proteins means more pieces of cheese per vat. According to John Umhoefer, executive director at Wisconsin Cheese Makers Association,   "This newer technology does seem to improve some of the characteristics of the cheese. Another component reduced through the membrane filtration is the lactose; the producer can better control browning on a melting cheese by controlling the amount of lactose in the end product."

He also notes that the filtered milk should not affect sliceability or shreddability, however, the concentrated proteins could impact melt characteristics.

Dean Sommer, cheese and food technologist at WCDR, says that reducing the lactose could help reduce acidity during cheese production. "Lactose is the fuel that produces acid. Because ultrafiltered milk removes the lactose in a significant amount, this could help the cheese maker make a better cheese."

In terms of the role lactose plays in browning, Sommer says, "In general, we get many more complaints for over-browning than under-browning, and most formulators are fighting over cheese that will brown less."

Cheese gets a workout in many different types of applications. Formulators want it to melt, but only to a certain degree, or soften, but not flow, and maintain its identity. According to Sommer, "There are a lot of ways to control melt in cheese. Sometimes you want to heat it, but want it to maintain some of its identity. Particularly in Hispanic-style applications, they might want to fry the cheese, yet have it maintain its identity."

Sommer indicates that melt and flow in natural cheese are best controlled through adjustments made to certain ingredients used during the cheese-making process, while still maintaining its identity according to federal standards.

Variations in cheese performance are important to developers creating appealing frozen foods or low-carb alternatives for consumers. Brian Degner, research scientist, sauce technology, ConAgra Foods, Omaha, NE, is working on Life Choice, a new line of carb-conscious frozen meals introduced in February.

Cheese is one ingredient of choice for a few reasons, including its melt and stretch properties. "The proteins in cheese have unique functional properties in that they are thermoplastic (melt when heated and thicken when cooled). This functionality gives sauces an extra quality trait compared to just formulating with starches," says Degner. "On the opposite end of thermoplasticity, cheese can be processed with specific phosphates to limit the melt. These restricted-melt products are desirable when cheese identity is needed."

Another concept seeing renewed interest, according to Sommer, is low- and no-fat cheeses, yet "with reasonably good flavor and functionality." In past years, he says, low-fat products were possible, but they "weren't the best" in terms of flavor. "Particularly with the recent concentration on childhood obesity we've seen renewed interest in low-fat cheese, but this time around they want the product to function and taste better," which he admits, "is a big challenge."

In addition to texture and functionality, another factor is economics. Sommer indicates that yield decreases in low-fat-cheese production, and consequently price is an issue.

But by far the biggest challenge a low-fat or no-fat formulation faces is flavor. Says Sommer, "In most cheeses we're familiar with, the dairy milkfat is such an important contributor to this flavor. The mimetics do help texture, but flavor is the biggest challenge."

What is contained in a cheese flavor profile? MaryAnne Drake, Ph.D., associate professor in the department of food science, Southeast Dairy Foods Research Center at North Carolina State University, Raleigh, has completed and is conducting several studies to determine just that. According to Drake, one of the basics to acknowledge is that, "Cheese has different degrees of umami. You'll see different degrees even within one type of cheese."

Drake is initiating, with Polly Courtney, Ph.D., associate professor at The Ohio State University, Columbus, a study to determine if organic acids, nucleotides or peptides initiate umami in cheese. "It's the combination of savory flavors in cheese (salty, sweet, brothy and nutty notes) that help cheese blend wonderfully with an assortment of savory dishes, from lentil soup to cheeseburgers," she says.

When topping that burger though, does natural cheese of the same variety have different flavor notes, depending on the region of the country it is produced? One can study that aspect of natural cheese in the "library" Drake has assembled the past few years. Twenty production facilities from four regions in the United States have contributed 40-lb. blocks of Cheddar three times per year for two years for a regional-cheese flavor study being funded by California Dairy Research Foundation, Davis.

Drake and her team have evaluated the cheeses with the developed cheese-flavor language after aging them for six, nine, 12 and 18 months. Drake studied these contributions to determine if regional differences exist in aged Cheddar-cheese flavor. Her findings were somewhat contrary to expectations and indicative of greater consistency than previously thought. She says, "Preliminary results indicate that, for the most part, there are no regional differences in Cheddar-cheese aged flavor. What it does reveal is different production facilities have their own flavor 'fingerprint.'"

In another research success story, Drake and colleagues have pinpointed the chemical compounds that give nutty flavor to aged cheese. "No other studies yet have identified the compound that causes this elusive flavor," says Drake. She points out, "If we know the compounds that cause these flavors we can link it back to starter technology or make procedures and tailor the cheese for levels of this compound to enhance the flavor." Currently, a team at Utah State University, Logan, is making cheese with adjuncts that produce these flavor compounds to determine if it is possible to control the flavor development and enhance the nuttiness in natural Cheddar cheese.

Drake's intense studies mesh with her belief that flavor is the most important aspect of natural cheese. "There is a wide variety when it comes to cheese flavor and there are no good and bad cheeses, just unique marketing opportunities. But what processors need to consider is that we aren't making a commodity product, and flavor matters," she says.

Despite attractive flavor, formulators have to consider the bottom line. Cheese prices are at an all-time high of more than $2.20 per lb. even as domestic production increases, with figures illustrating an overall 7.9% increase for all combined natural-cheese categories when comparing Feb. 2004 to the same period in 2003. However, according to Kevin Delahunt, president of the food ingredients division for Sargento Foods Co., Plymouth, WI, "Like any other food commodity, cheese prices go through cycles. We're confident they will come back down."

In addition, Delahunt says, "We believe and have built our company's services on the premise that product designers can achieve great cheese flavor with either natural or processed cheese." And that is the good news. In addition to natural cheeses, developers can count on other options to enhance product flavor by using other forms that fall outside the natural-cheese definition, including processed cheese, other cheese products or dairy flavors.

Historically, American, Cheddar and Italian-style cheeses and flavors continue to lead the pack in volume; however, both suppliers and cheese customers indicate new flavors are rising in popularity. Omhoefer notes that there is a "great blossoming of farmstead or artisanal cheese makers in this country." He says that nationally, about two-dozen new farmstead-cheese makers appear each year. These smaller facilities utilize the Internet, farmers' markets or local retail markets to distribute their wares.

Larger manufacturers are taking note of this trend and responding to customer requests for greater variety. Delahunt says, "We have seen an uptick in the interest among our customers for highly flavored specialty cheeses, such as Cotija and Parmesan, or flavored cheese sauces, to bring big, new flavors to consumers interested in variety."

This trend isn't confined to the supermarket aisles. In fact, the nation's third-largest quick-service restaurant (QSR) is looking to liven up the menu with alternative cheese flavors. J.J. Schultz, dairy manager for Wendy's International, Dublin, Ohio, says, "There is a lot of interest in nontraditional cheese for the unique flavor and visual profiles they deliver." Yet often, sufficient supply remains a big challenge to introducing a uniquely flavored, nontraditional natural cheese onto a national menu.

For example, Wendy's has 6,000 North American outlets. Schultz says, "Currently, in niche markets, there isn't enough (cheese supply) for us to do a national product rollout." Yet, he adds, market research demonstrates that not only is the company's customer base loyal, but also eager for uniquely flavored menu items. The firm's Southwest Chicken Caesar salad included natural shredded Parmesan cheese, croutons and marinated, spicy chicken cubes.

Last December, in its Wild Mountain promotion, the company highlighted a sandwich with a ¾-oz. natural Colby-Jack cheese slice, and a Hot 'n Spicy Southwest pepper sauce with zesty flavor. However, the buttery flavor of the cheese provided a balance to the spicy sauce. All in all, notes Schultz, Wendy's customer base wants something that not only satisfies hunger, but is a bit "edgy," and the company needs cheese processors to step up to the plate, not only in terms of flavor, but functional performance and quality. "A primary concern with natural cheese for any QSR is that there is far too much variation of product from same the facility or company," he adds.

Schultz says that a key advantage for processed American cheese is that it possesses functional and flavor consistency characteristics that place it ahead of its natural-cheese competition. "It is an extremely consistent product -- the same melt, flavor and size every day," he notes. "But with natural cheese and the differences from the beginning to the end of run, you wouldn't believe it's coming from the same facility -- different texture, color, melt, etc. And the American consuming public wants the same product every time they buy it."

Schultz urges processors to think of their product a new way. "When dairy processors are considering new product development, I would encourage them to think of cheese as part of the whole system. For instance, if we put on a piece of Cheddar (on a sandwich), we may want the cheese to deliver color -- a rich, yellow glow; a certain texture -- how it complements the build of a sandwich on top of ham; visual appeal -- melted with edges turned down; and certainly be a part of the flavor system. Think in broader terms, that your product is an ingredient or component, not simply a stand-alone product," he says.

Cheese powder is most definitely not a stand-alone product, yet it is an attractive alternative for some formulators looking to add richness and flavor notes while providing economic benefits.

Cheese powder has no standard of identity but basically starts with a spray-dried cheese slurry, of either one variety or a blend, which is then mixed with other dairy ingredients, such as dried whey or nonfat milk, and usually a colorant. A formulator would use no more than 10% to 15% cheese powder in a finished product. But due to the lack of standards of identity, the actual percentage of real cheese within that powder can vary from 5% to a possibility of 30% to 40%.

For sauce applications, cheese powder might contain emulsifiers to ensure a smooth blend when mixed with a liquid. Primary applications for cheese powders remain mixes, sauces and snacks. Other practical considerations when using cheese powder instead of a hard cheese could be convenience in handling, storage and shelf-stability.

One continuing issue with conventional cheese powders has been the loss of volatile flavor compounds during storage or especially during high-heat treatments. New in this arena is a product that took six years to perfect, according to Aly Gamay, president of R&D activities, Gamay Flavors Inc., New Berlin, WI. "The most exciting development is our heat-stable cheese flavor, Ultra Withstand." He says this heat-stable flavor is especially important in the baking industry, for applications such as cheese-flavored crackers.

For a flavor ingredient such as this one, the usage level is about 2% to 3% in finished product with an average price of $3 per pound, versus the alternative use of about 10% Cheddar at the current market rate.

Another advantage, according to Gamay, is that "the flavor notes are strong and the formulator does not have to ferment the dough." This saves time, money and ensures end-product consistency. When a product is fermented, the flavor development can vary with temperature and duration.

Another area where heat stability is critical is in retort product, such as soups and meats. Says Gamay, "The difference between concentrate and conventional enzyme-modified cheeses (EMCs) is that these flavors are more balanced and concentrated. They bring out all the notes when used correctly."

At Butter Buds Food Ingredients, Racine, WI, Bill Buhler, general manager, says the flavor in these products is "from two to 80 times as intense as equal weights of natural cheese." This allows for very low usage levels of 0.5% to 1.0% in finished formulations. In addition to Cheddar and Italian profiles, the company has recently added more ethnic-profile flavors like Asiago, Cotija and Manchego, available in water-miscible powders or oil-soluble pastes. These allow the developer to have a consistent flavor profile but look to other ingredients for functional characteristics.

Buhler says these flavors are popular with companies developing "nutrition-oriented foods. These flavors deliver a well-rounded profile with all the flavor notes that results in a full, rich taste. The complexity of the flavor profile also helps to enhance the eating experience by providing a rich mouthfeel perception." He adds that companies making healthy foods often turn to flavor systems to help solve sensory difficulties: "They want good nutrition but with a rich, savory flavor. Since these products contribute virtually no fat to the finished system, sensory and nutritional objectives can be met."  

Again, the company considers this particular product far different than an enzyme-modified ingredient. Says Buhler, "The technology used is very unique and proprietary. What it yields is a natural dairy concentrate that allows the formulator to label their product with 'natural cheese flavor.'"

Trends can build slowly or have a sudden, powerful impact on the marketplace. Earlier this year, WMMB forecast cheese trends for 2004, predicting growth in the organic segment. Organic cheese has existed for years in smaller, specialty outlets. Now, as if to put a stamp of authenticity on this prediction, in February of this year Kraft Foods Inc., Glenview, IL, announced the introduction of an organic cheese to the larger retail arena.

Cheese also fits especially well into the rapidly accelerating speed-scratch phenomenon. A Packaged Facts report issued in Feb. 2004 states approximately 44% of weekday meals in the United States are prepared in 30 minutes or less and consumers would prefer that figure to be even lower. Not surprisingly, considering this preference, from 1999 to 2003 the overall market for ready meals and side dishes grew by 39% and posted $19.6 billion in sales figures for 2003.

Pamela Schoenster, associate principal scientist, Kraft Food Ingredients Corp., Memphis, TN, says, "Cheese is a great way to give a homestyle or upscale feel to the meal kits some manufacturers are putting together." She might recommend a pasteurized specialty cheese for its performance characteristics as opposed to natural cheese because "if you want to have cheese in a blend of things, it may fracture if you have an elongated shred."

And without cheese, low-carb aficionados wouldn't have an expansive flavor array to liven up their menus. Schoenster says, "Cheese is really a great tool to use; it is low in carbs but gives people a feeling of comfort. It can be homestyle or, depending on the application, deliver exciting trend profiles, such as Mexican or Italian."

When ConAgra announced its new low-carb introduction in February, quite a few meals included cheese. About the Life Choice line, Degner says: "Cheese is low in carbohydrate content and also high in protein -- a key point of nutrition delivery in Life Choice meals. Cheeses such as Parmesan, Cheddar or mozzarella are shredded or grated over components as a garnish, which adds flavor, attractive texture and appearance when melted during final meal preparation. These cheeses also add additional protein to the meal."

Cheese sauce is making an increasing appearance in prepared-food products, not only in the low-carb market. Says Degner, "Cheese is used in sauces for taste, texture and eye appeal, plus its low-carbohydrate content." In addition, he says, "When properly formulated, cheese sauces or cheese as garnish perform very well in frozen meals due to their freeze/thaw stability and microwave heating performance."

Delahunt has seen evidence that cheese sauce is a growing category in institutional or foodservice markets and in further-processed food. "In both foodservice and the food-ingredient world, our sauce capability is an important and growing capability and one which our customers are encouraging us to develop." As to why the growing popularity, he explains it this way: "Sauce is a fantastic and relatively inexpensive way to add flavor and visual interest to foods. Retail, chain quick-service and chain casual dining are seeking high flavor."

Pasteurized specialty cheese poses an attractive sauce-ingredient option. Schoenster says: "Restricted-melt cheese sauces lend formulas a high amount of natural cheese flavor yet provide cost optimization. Also, they help make a sauce with a nice velvety texture. In addition, these ingredients are consistent throughout their shelf life and can be pumped or extruded at refrigerated temperatures. So, for cost optimization, the customer gets a cheese profile with consistent melting character -- whatever the product was at the time it was pasteurized, it remains, because the aging process halts with pasteurization."

These restricted-melt cheese sauces contain high amounts of natural cheese, yet uses, according to Schoenster, "some optimizing ingredients. There is a lot more standardization and a much more consistent product day in and day out. We can give a customer different variations on melt and flavor profiles."

Kraft's pasteurized specialty cheese comes in 20- or 45-lb. block form. Different flavor varieties currently include American, mozzarella and Monterey Jack with peppers. Some have a mild flavor profile, which enables a product developer to determine flavor direction. Schoenster says, "A developer can customize a pasteurized cheese sauce by adding a flavor to take them into a certain direction. A white one can have a sharp-Cheddar profile or a Parmesan and three-cheese and turn it more toward an Alfredo profile."

Schoenster says the product also poses advantages in sandwich usage, particularly in foodservice. "A QSR can dispense it or put it under a heat lamp. It softens but it doesn't 'travel.'"

In the end, common sense and consultation rule the day. The cheese supplier is the best information source for the best ingredient to suit desired taste profiles and performance expectations in a finished product. As Delahunt put it, "The cheese they (our customers) select is heavily dependent on the application. Whether it is refrigerated, frozen or shelf-stable, that is the No.1 determinant of whether they select a natural cheese, processed cheese or sauce, and we can provide a tremendous variety in any one of those three areas."

Jeanne Turner is a freelance writer with more than 10 years of experience writing about the functional properties of food ingredients.