Cheese Making is a Complex Science – A Food Chemist Explains

Cheese is a relatively simple food: it’s made from milk, enzymes (proteins that break down other proteins), bacterial cultures, and salt. The cheese-making process involves complex chemical reactions.This determines whether the cheese will be soft and gooey like mozzarella or firm and fragrant like Parmesan.

In fact, humans have made cheese About 10,000 yearsRoman soldiers were given cheese As part of foodIt is a nutritious food containing protein, calcium and other minerals. Its long shelf life allows it to be transported, traded and shipped over long distances.

I Food Scientist He has studied cheese chemistry at the University of Wisconsin for the past 35 years.

In America, cheese is primarily made from cow’s milk, but there is also cheese made from the milk of other animals, such as sheep, goats, and even buffalo and yaks.

Unlike fermented dairy products such as yogurt, cheesemakers remove the whey (water) to make cheese. Milk is about 90% water, but cheeses like cheddar are Moisture content is less than 38%.

Milk is perishable and spoils quickly, so removing the water from milk to make cheese results in a harder, more substantial product with a longer shelf life. Before the invention of refrigeration, milk would go sour quickly. Making cheese was a way to preserve the nutrients in milk so it could be eaten weeks or months later.

How is cheese made?

All cheesemakers start by pouring the milk into a cheese vat and adding a special enzyme called rennet, which destabilizes the milk’s proteins. Get together and make a gelCheesemakers basically make milk from liquid. In gel form.

After about 10 minutes to an hour, depending on the type of cheese, the cheesemaker cuts this gel, usually into cubes. Cutting the gel separates some of the whey (water) from the cheese curds (which are made from clumped milk and look like a yogurt gel). As the gel is cut into cubes, tiny holes, or openings, in the gel allow the water to escape over the surface of the newly cut piece.

A cheesemaker’s goal is to remove the amount of whey and water from the curds needed for a particular recipe. To do this, the cheesemaker stirs and/or heats the curds to release the whey and water. Depending on the type of cheese being made, the cheesemaker will drain the whey and water from the vat, leaving only the cheese curds behind.

For harder cheeses like cheddar, cheesemakers add salt directly to the curds while they are still in the tank. Releases more whey and waterThe cheesemaker then packs the curds into a mould or ring – a container that holds the curds in a block or ring – and applies pressure to the curds, which forces them into the ring and causes them to intertwine, forming a solid mass of cheese.

Cheesemakers also produce other cheeses, such as mozzarella. A salt solution called brineCheese blocks or wheels are floated in a tank of brine for hours, days, or weeks, during which time the cheese absorbs the salt, developing flavor and preventing spoilage. Unwanted bacterial and pathogen growth.

Cheese is a living fermented food

While cheesemakers are completing all these steps, several important bacterial processes are going on: Cheesemakers add cheese cultures, the bacteria that create specific flavors, at the beginning of the process. Adding them while the milk is still liquid gives the bacteria time to ferment the lactose in the milk.

Historically, cheesemakers used raw milk. Bacteria in raw milk The cheese was soured. Now, Cheese makers use pasteurizationwith gentle heat treatment Destroys all pathogens The bacteria is present in raw milk, but processing it means that cheesemakers need to add back bacteria called a starter, which “kicks off” the fermentation process.

Pasteurization offers cheesemakers a more controlled process because they can choose to add specific bacteria rather than the bacteria found in raw milk. Essentially, These bacteria eat (ferment) sugars– lactose – and in the process produces lactic acid and other desirable flavour compounds found in cheese. Like diacetylIt smells like hot buttered popcorn.

Depending on the type of cheese, these bacteria remain active in the cheese long after it leaves the cheese vat. Many cheesemakers age their cheeses for weeks, months, or even years to allow more time for the fermentation process to develop desirable flavors. Aged cheeses include Parmesan, aged Cheddar, and Gouda.

Essentially, cheesemaking is a process of concentrating milk. Cheesemakers want their final product to contain as much of the milk’s proteins, fats, and nutrients as possible, and not too much water. For example, the main milk proteins captured in the cheesemaking process are: Casein isMilk contains about 2.5% casein, but finished cheeses such as cheddar contain about 25% casein (protein), meaning cheese contains lots of nutrients, including protein, calcium and fat.

The infinite possibilities of cheese

There is Hundreds of varieties All cow’s milk cheeses made around the world are made from cow’s milk. All these different varieties are produced by tweaking the cheese making process.

For cheeses like Limburger, cheesemakers apply a smear (a solution containing different types of bacteria) to the surface of the cheese during the ripening process. For other cheeses, like Camembert, cheesemakers place the cheese in an environment (such as a cave) that is conducive to the growth of mold.

Others include bandaged cheddar cheese. Wrapped in bandages Or cover with ash. Covering the surface of the cheese with a bandage or ash can help prevent excessive mold growth and reduce moisture loss through evaporation, resulting in a harder, more intensely flavored cheese.

Over the past 60 years, cheesemakers have figured out how to select the right bacterial cultures to create cheeses with specific flavors and textures. The possibilities are endless, and only the cheesemaker’s imagination knows the limits.

John A. Lucey is a professor of food science at the University of Wisconsin-Madison. This article is reprinted from conversation Under Creative Commons License. read Original Article.