Cheese making
How cheese is made
The high-quality and efficient production of Australian milk makes it ideal for high-quality cheese. Made predominantly from cows’ milk (with some from goats, sheep and even buffaloes), full-fat and partly or fully skimmed milk is used depending on the style of cheese being produced. The composition and quality of cheese is affected by a number of factors, including the breed of cow, lactation cycles, feed, weather and even the individuality of each cow.
Quality milk provides a solid start to making cheese, but the process demands care and patience - often with hands instead of machines.
Take a look at the different cheese types, and how they’re made:
- Farmhouse cheese: cheese made on the farm using milk produced only on that farm
- Farmhouse-style cheese or artisan cheese: cheese made on the farm or smaller factories using their own milk and other local milk - the cheese is generally handmade.
- Specialty cheese: specialty cheese refers to all cheeses other than bulk cheddar, mozzarella or processed cheese.
- Reduced-fat cheese: in Australia this cheese has at least 25% less fat than regular cheese of the same kind
- Low-fat cheese: low-fat cheese typically has no more than 3% fat content
- Processed cheese: a blend of natural cheddar cheese of different ages, melted and cooked with emulsifying salts and water which is then extruded, packaged and cooled rapidly - which reduces shelf life. Block processed cheese is allowed to cool slowly over 24 hours, and can be stored without refrigeration
The cheesemaking process involves a number of different techniques.
The cheese making process
Standardisation makes milk consistent by using a filter, which adjusts the ratio of proteins and fats to a preset value. Most cheese in Australia is made using standardised milk. Some small cheesemakers don't do this as they milk cows themselves. Standardisation gives a consistent quality product and minimises wastage.
Pasteurisation is the process of heating milk quickly to 72°C for 15 seconds, then rapidly cooling it. This destroys pathogenic microorganisms, and gives a more consistently safe product and improves the keeping quality of cheese. Some hard cheeses matured for more than three months might use unpasteurised milk but only if they follow strict rules.
Starter cultures vary, but nearly all have acidifying starters to produce lactic acid from lactose (sugar in milk). Some cheeses have additional cultures to assist during maturation. They are all different types of bacteria that help create unique flavours and textures. Mould spores are sometimes added depending on the type of cheese.
For example:
- Penicillium candidum grows as a white mould on brie and camembert.
- Penicillium roqueforti are blue mould spores that help blue mould growth in blue vein cheese
- Gas-producing starter or Propionibacterium shermanii known as 'props' bacteria create the eye formation in Swiss cheese types
- Aroma cultures or Brevibacterium linens are used for rubbing the surface of washed rind cheeses to produce colour and flavour
- Geotrichum candidum is used on several surface-ripened cheeses to alter the flavour, aroma and colour of the cheese
Coagulation of the milk is the first step in converting liquid milk to a solid cheese. Fresh cheese is coagulated by lactic acid from starter cultures. For matured cheese an enzyme known as chymosin, found in rennet, is added to form a curd. More recent technology has enabled cheese makers to use rennet from non-animal sources such as yeasts and fungi. When the milk is set, the curd releases whey which concentrates the curd.
Syneresis, the release of moisture from the curd, occurs after the curd has been cut. Finely cut curds release more whey, creating drier cheeses. For example, the curd for parmesan (low moisture) is cut the size of rice grains while the curd for a brie or camembert (high moisture cheeses) is usually cut to about 2 cm cubes.
Stirring keeps the cut curds apart and helps to release more whey. The type of cheese being made will influence the length of stirring required. Generally soft cheeses require less stirring than harder cheeses.
Cooking the curds is a gentle heating process that helps remove more whey. Most fresh cheeses are not cooked, while drier matured cheeses are. Cheddar is heated to 38°C, romano to 46°C and parmesan and gruyere to 54°C.
Salt enhances flavour, preserves cheese, reduces moisture and can also restrict the growth of undesirable bacteria. Most cheeses are salt brined except for cheddar types, which are dry salted by adding salt to curd chips prior to hooping. The cheese is placed into a brine solution of 20-26% salt for a fixed time. The time in the brine depends on the cheese size and desired salt level. Some cheeses also have their surface (rind) washed with a brine solution during maturation. This helps restrict mould growth and aids the development of the rind.
Once the curds are firm enough and have the right acidity they are placed into hoops or moulds to form the shape of the cheese. The cheese stays in the hoops for up to 16 hours.
Most semi-hard to hard cheeses are pressed in mechanical presses though most soft cheeses are not pressed. Pressing assists curd fusion, closes the texture and helps remove more whey.
During maturation enzymes in the cheese break down the fats and proteins, creating texture and flavour. The main enzyme sources are the milk, starter and rennet, while hard Italian-style cheeses may also have lipase added to speed up fat breakdown and contribute to their unique flavour. Maturation of rind-less cheeses usually takes place in temperature-controlled cool rooms. For example, cheddar requires 8–10°C for 3–24 months. Rinded cheeses require humidity as well as temperature control. White mould cheeses require 95% humidity and 11–14°C.
Fresh cheese is packaged as soon as it’s made, and usually boxed to prevent damage.
White mould cheese must be able to breathe through its wrapping as it continues to ripen. The wrapping therefore plays a big part in the successful maturation process.
Blue cheese is generally wrapped in laminated foil to prevent the rind from drying out.
Cheddar is most commonly wrapped in a vacuum-packed bag. More traditional methods such as waxing and wrapping in cloth are used for specialty cheddar.
Prior to cutting the curd, the cheesemaker checks to ensure the consistency is correct.