Why does cheese taste like cheese? Food experts explain how microbes work magic

Nothing beats a holiday cheese board. Sure, you may eat cheese all year round, but the holidays are the perfect excuse to indulge in varieties you wouldn’t usually slide into a sandwich.

Maybe you’re looking forward to reaching for a rich, sharp Cheddar to layer on a cracker topped with chutney. Or picking up a piece of toasted bread to dunk into the gooey, warm center of a wheel of Camembert.

But have you ever wondered how all the different types adorning your festive cheese board, from the hard to the soft, the fragrant to the stinky, are created?

How cheese is made

Most of us know cheese is made of milk. But the transformation of a carton of milk into a slab of cheese is a complex one.

Cheesemakers take fresh, raw milk — often from cows, but sometimes from goats, sheep, yaks, and even horses — and heat it up to pasteurize it and kill off any harmful pathogens and make the finished product last longer.

Counterintuitively, cheesemakers then add bacteria back into the milk in the form of a starter culture, which in turn, transforms lactose sugar in the milk into lactic acid. This is when the milk starts to ferment. Once there is enough lactic acid in the mix, cheesemakers add in an enzyme called rennet and curdle the milk. At this point, the mixture resembles cottage cheese — with lumps of curds swimming in watery whey. The whey is generally drained off, and then many cheesemakers add salt or other flavorings at this point. Then, the cheese is left to age and dry. Some cheeses, like Parmesan, are left to age for a year or more.

Turning milk into cheese also turns the dairy product from a commodity that lasts (at most) weeks into one that lasts (potentially) years. Yet both are filled with nutritional goodies, like fats, proteins, vitamins, and minerals.

Different cheesemaking traditions customize the basic milk-cheese transformation process to produce different results. The flavor, texture, appearance, and aroma of cheese are determined by various factors, like the animal the milk comes from, what it ate, the type of starter culture used, the aging methods, and much more.

For example, mozzarella is stringy because it’s kneaded as it’s formed. Swiss cheese has holes because the bacteria in it produce carbon dioxide, which leads to bubbles. A mild Cheddar might be matured for two to three months — but a sharp Cheddar for five years.

The big cheese

There are many ways to create different types of cheese. But cheese as we know it is also under threat.

We won’t lose out on Cheddar or suffer a great mozzarella shortage any time soon. It’s a little more complicated than that, and it’s to do with those all-important starter cultures.

“Increasingly, producers around the world are using the same few cultures to create flavors, aromas, and textures,” Carlos Yescas, a social entrepreneur and cheese expert currently working with dairy and cheese producers in Latin America, Europe, and United States, explains to Inverse.

In the past, cheesemakers would have made their own starter cultures — a tradition now called “natural cheese-making.” But in the modern era, this artisanal approach is rare. Cultures increasingly come from a small selection of labs that make culture on an industrial scale, Yescas says. These cultures are packaged up, sometimes freeze-dried, and sold in a form easy for cheesemakers to use safely.

The easy and abundant supply means many kinds of cheese around the world use the same starter culture. Because the culture dictates crucial attributes of cheese, like flavor and texture, the relatively few varieties of culture available may have some unintended consequences.

“The loss of diversity is detrimental to everyone,” Yescas tells Inverse. “It creates monocultures susceptible to factors that can disseminate entire colonies and allow for pathogens to spread more widely.”

He also believes relying on commercial cultures could push small producers out of the cheese-making industry for good. “We have seen conglomerates buy up medium size companies and push further into the market to the detriment of access to small producers,” Yescas says. “The playing field is becoming increasingly uneven, and I worry that we will end up with generic cheese everywhere.”

Commercial cultures

So-called “natural” cheese making has a long history — an estimated 4000 years — and leads to cheese specific to certain regions, even certain farms. But it can be difficult to make a starter culture and then use it to produce cheese, with many challenges arising throughout the process.

In comparison, starter cultures made in labs are rigorously tested for safety and efficacy. This makes for safer, more reliable cheese, as there’s less chance of contamination from harmful bacteria and, therefore, more peace of mind for cheese makers. In other words, Cheddar cheese is reliably safe to eat and tastes as we expect.

Inverse spoke to Tom Perry, the Cheese Sales Manager of Shelburne Farms, who explains commercial cultures also ensure more consistency and control. “Cultures, now especially, can be designed, particularly on these huge industrial scales, to stop acidification at certain pH levels, work faster, cut through certain amino acids and proteins to achieve certain desired texture and flavor profiles,” he says.

For many cheese producers, commercial culture is safer, more effective, and more cost-efficient in the long run.

“I do feel like there’s the potential for there to be a, no pun intended, monoculture,” Perry says. “However, even within the cheesemaking community, there are different culture blends to produce different styles of cheese. And even within those cultures, there are infusions of new cultures primarily to prevent phage (viruses that kill the culture).”

For these reasons, Perry is optimistic about the future of the cheese industry but acknowledges it might be on a smaller scale. “I think for every five acts of consolidation and contraction, there will be a new cheesemaker, a new independent shop, or a new small-scale distributor,” Perry explains. “Human nature is all about ebbs and flows, and cheese is no different.”

It’s also important to remember that, even with commercial cultures, cheesemakers can still make cheese their way. “I believe that as long as there are independent farmers with milk, a vat, an aging space, and a means to sell it, there will be diversity in cheese,” Perry says.

“Native cultures may be lost before we have time to study them,” Yescas counters. “This is currently happening in places like Brazil and India. I see this as a form of neo-colonialism at the microbiological level.”

Because traditional methods of food production are passed down through generations, a loss of diversity may mean that people across the world risk losing a major part of their culture, history, and identity.

Delivering diversity

Concerns about the future of cheese point to broader issues within the food industry. It may seem like we have more choice than ever about what we eat, but like cheese starter cultures, many foods are now dominated by only one or two types or providers.

In his book, Eating to Extinction, journalist Dan Saladino writes:

“What we’re being offered appears at first to be diverse, until you realize it is the same kind of ‘diversity’ that is spreading around the globe in identical fashion; what the world buys and eats is becoming more and more the same.”

He explains that many of the world’s plant seeds are controlled by only four corporations and that one in four beers consumed around the globe come from a single brewer. Pork is mainly produced from a single breed of pig, and while there are more than 1,500 types of banana, most of us only eat one, the Cavendish.

Why does this matter? Well, food might be less nutritious and flavorful because we (unknowingly) only experience a small slice of it. But Saladino also explains that a lack of diversity in food is ultimately a vulnerability.

“A global food system that depends on just a narrow selection of plants — and only a very small number of varieties of these — is at a greater risk of succumbing to diseases, pests and climate extremes.”

We may not see much diversity in our grocery stores, but some scientists are working to record what Saladino calls “endangered foods.” From a vault in Svalbard containing more than a million seeds to the universities and research institutions where a wide variety of foods are analyzed and cataloged. For example, at the University of California Riverside, more than 1,000 types of citrus are conserved as part of the Givaudan Citrus Variety Collection.

Other initiatives have emerged in recent years, like the Ark Of Taste. Run by the Slow Food Foundation For Biodiversity, the project aims to help people rediscover some foods and preserve others.

Yescas says this kind of research and preservation is essential for the future of the cheese industry — especially when it's not in the hands of the private sector. “This allows for different types of knowledge to emerge and for more people to benefit from this knowledge,” Yescas explains. “I hope the vibrancy of cheese research continues, and I would encourage people to study more, to ask more questions, but overall to question the status quo.”

TASTE OF THE HOLIDAYS is an INVERSE series about the science of food supported by Target. Get the inside scoop on your favorite (or hated) nostalgic holiday dishes via our hub, which will update with new stories through December 2022.