The Science Behind Your Cheese

Some cheeses are mild and soft like mozzarella, others are salty-hard like Parmesan. And some smell pungent like Époisses, a funky orange cheese from the Burgundy region in France.

Camembert is a cheese with fuzzy rinds that can be found in mountain caves in northern Spain.

Almost all of the world's cheese starts the same as a white lump of curd.

How do we get away from that blandness? The answer is related toMicrobes. There are cheese teems with different types of yeast andbacteria. According to a senior researcher at the Dairy Research Institute of Asturias in Spain, there are more than 100 different types of organisms in a single cheese. Cheese isn't just a snack, it's an environment. Billions of microbes are found in every slice of cheese.

Since the late Stone Age, people have made cheese, but only recently have scientists begun to learn about the deadly skirmishes, peaceful alliances and beneficial collaborations that occur between the organisms that call cheese home.

Scientists sample cheese from all over the world in order to find out what is in the cheese and where it comes from. They can identify which organisms are in the cheese by using existing databases. Ben Wolfe likes to say that the way they do that is similar to a crime scene investigation.

There were surprises early on. Cheesemakers often add starter cultures of beneficialbacteria to their cheese to help it get to its destination. When Wolfe and his group looked at ripened cheeses, they found that the mix of microbes in the cheese was very similar to those cultures. More than half of thebacteria were not from the starter culture. They came from where?

We usually know from places other than cheese the people who turned out to be old acquaintances. There is a microbe present in soil, chicken litter, and even an Etruscan tomb. Salt ponds and marine environments are associated with the Halomonasbacteria.

The stinkiness of Limburger has been linked to Brevibacterium linens. It can be found between our toes when not on cheese. The smell of sweat is added to by B. linens. It is true that the same organisms are involved in dirty feet. Wolfe once pointed out that the organisms on feet and cheese looked the same. An artist in Ireland demonstrated this by culturing cheese with organisms plucked from people's bodies.

Researchers were surprised by how some of the organisms ended up in cheese. They were sampling the environment of cheesemaking facilities. The microbes in the milk of cows come from the beginning. The milk and cheesemaking process picks up more than one person. If the soilbacteria attach themselves to the teats of a cow and end up in the milk pail, it could be a problem. The skinbacteria fall into the milk from the hand of the milker. The milk can be entered from the storage tank or from the walls of the facility.

Some organisms are brought in far from home. Wolfe and other researchers think that marine organisms such as halomonas can get to the cheese through the sea salt in the brine that cheesemakers use to wash down their cheese.

A simple, fresh white cheese like petit-suisse from Normandy might have a few different types of organisms in it. Hundreds of different kinds ofbacteria and fungi have been found in long-ripened cheese. More than 400 different types of cheese have been found, according to the researcher. Scientists have observed that there can be a sequence of settlements whose rise and fall can match that of an empire.

Bethlehem is a cheese made by Benedictine nuns in Connecticut. Bethlehem changes from a rubbery, smooth disk to one with a dusty white rind and a dark surface between the day it gets made and when it's fully ripe about a month later. If you were to look with a strong microscope, you could see that the initial smooth rind becomes a rugged, pocketed terrain so densely packed with organisms that they form biofilms. A gram of rind from a fully ripened cheese could contain 10 billion organisms.

The process usually begins quickly. Lactic acidbacteria are usually the first colonizers in milk. Acid is produced from the sugar in the milk by these LABs. The milk becomes sour due to the increased acidity. Paul Cotter, a microbiologist at the Teagasc Food Research Centre in Ireland, wrote about the flora of cheese and other foods in the annual review of food science and technology.

Some yeasts such as Saccharomyces cerevisiae can live in this acid environment. The LABs produce lactic acid, which these microbes feed on. They neutralize the acidity in order to allow otherbacteria to join the cheesemaking party.

Territorial struggles can occur as the different species settle in. A study in 2020 looked at 55 artisan Irish cheeses and found that almost one in three had genes needed to make weapons. It is not known if or how many of these genes are switched on. He hopes these compounds will one day be used for new antibiotics.

The cheese microbes work together. The Saccharomyces cerevisiae yeasts return the favor by manufacturing vitamins and other compounds that the LABs need. Wolfe's team has found that threadlike fungus can act as a road for surfacebacteria to travel into a cheese.

You might have begun to suspect that cheese is about decomposing. Like a rotten log in the woods, the organisms in cheese break down their environment. This makes cheese taste better.

cheese shows us what goodness can come from decay, according to the cheesemaker at the Abbey ofRegina Laudis. Humans don't like looking at death because it means separation and the end of a cycle It is the beginning of a new thing. The smell and taste of cheese is created by decomposing it.

The way the microbes build flavor is being investigated. It's less understood. There are a few things that stand out Lactic acidbacteria produce volatile compounds that can be found in butter and give cheeses a rich, butter taste. A blend of alcohols, fatty acids and other compounds brought forth by a yeast called Geotrichum candidum gives a fruity aroma to cheese such as Camembert. Butyric acid and volatile sulfur compounds blend into the flavor of many mold-ripened cheeses like Camembert. Different strains of microbe can make different tastes.

The cheesemaker sets the conditions for therot of the milk. Julia Pringle is a microbiologist at the Vermont cheesemaker Jasper Hill Farm. Streptococcus thermophilus is perfect for making cheese because it thrives in heat.

A softer cheese like Camembert will result from the fact that the cheese is cut into large chunks. On the other hand, small cubes of curd drain better, resulting in a drier curd, which is something you want for.

The amount of salt added to the young cheese will increase as it is stored at cooler temperatures. When cheesemakers wash their ripening rounds with brine, they impart seasoning but also promote colonies of salt-lovingbacteria that create a specific kind of rind.

Changes in the way a cheese is handled can affect the cheese itself. If you switch on the air exchanger in the ripening room, you will be able to get more oxygen to flow around the cheese and mold will not be there before.

The same communities of microbes will show up again and again if the conditions stay the same. Almost everywhere, the same microbes can be found. If a cheesemaker sticks to the recipe for a Camembert, the same species will flourish and an almost identical kind of Camembert will develop.

According to some cheesemakers, cheese has a specific taste that is tied to its geography and is found in the vineyards. The same cheese type always tastes the same no matter where or when it is made.

Some organisms have been making cheese for a long time and have become domesticated. He is studying the changes in cheese starter cultures. When making the next batches of cheese, cheesemakers in Switzerland usually hold back some of the cheese to use again. Some starter cultures have been continuously backslopped for a long time. During that time, the backslopped microbes have lost genes that are no longer useful for them in their specialized environment in the dairy industry.

Over time, cheesemaking has become tamer and cleaner, and this has had consequences for the environment. Many cows are milked by machines and the milk is sucked directly into the closed system of hermetically sealed, ultra-filtered storage tanks, protected from the constant rain of microbes from hay, humans and walls that settled on the milk in more traditional times.

Pasteurization is when the milk is heated to high temperatures to kill the germs that are in it. They are replaced with start cultures.

The cheesemaking process has been made more controlled by this. It also means that there is less diversity in our cheese. Many of our cheddars, provolones and Camemberts have turned into lawns. Less diversity means less flavor because every microbe contributes its own signature mix of chemical compounds to a cheese.

Annual Reviews has a magazine called Knowable.

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