How cheese is made
Cheese-making is a
four-step process: curdling (or coagulation), draining and
flavouring, moulding and pressing, and ripening or ageing.
Curdling or coagulation is the separation of the solid from the
liquid components (whey separation) which is achieved by adding
ripening cultures such as rennet or lactic acid bacteria. All
cheeses are put through this process. There are two basic curdling
methods and these are determined according to the type of cheese
being made.
Sour-curd cheeses are made by adding lactic acid bacteria to milk, which make it clot into small grains of curd. Fresh-curd cheeses, cottage cheese, ricotta cheese and soft-curd cheeses like Brie and Camembert are examples of sour-curd cheeses.
Rennet cheeses are made by adding an enzyme which causes the formation of larger grains of curd. Hard cheeses are made this way.
Some cheeses are made by mixing both sour curd and rennet. Veined cheeses and semi-firm cheeses are examples of sour-rennet cheeses.
Sour-curd cheeses are made by adding lactic acid bacteria to milk, which make it clot into small grains of curd. Fresh-curd cheeses, cottage cheese, ricotta cheese and soft-curd cheeses like Brie and Camembert are examples of sour-curd cheeses.
Rennet cheeses are made by adding an enzyme which causes the formation of larger grains of curd. Hard cheeses are made this way.
Some cheeses are made by mixing both sour curd and rennet. Veined cheeses and semi-firm cheeses are examples of sour-rennet cheeses.
Draining consists in separating the curds and the whey to obtain
the required moisture content for cheese. Sour curd is drained by
letting the whey filter through the grains of curd into another
tank for several hours at a time. To drain rennet curd, several
active or manual techniques are used like stretching, kneading,
cutting, mixing and heating.
When a curd mass is placed in a cheese mould, it expels more whey
and draws together. As a rule, hard cheeses are submitted to more
pressure and have lower water content. For cheese types that are
meant to have a relatively high water content like sour-curd
cheeses, pressing is done by letting the upper layer of curds press
down on the lower layer. Rennet cheeses are submitted to different
levels of active pressure to the curd mass. It is sometimes heated
as well.
The curd
is transferred into perforated moulds of different shapes and sizes
to continue whey expulsion or draining. Pressing is usually
reserved for hard and semi-hard cheeses, but semi-soft cheeses are
also lightly pressed. Cheeses are sprinkled or rubbed with salt or
put in a brine bath. Salt acts as an antiseptic and also
contributes to skin or rind formation and flavouring.
Finally, cheese can be waxed and sealed with Penicillium, or bacteria. It can also be washed in water, alcohol or brine. The cheese may also be covered with wood ashes, herbs, oil, or it can be smoked or painted like Port-Salut and Saint-Paulin.
The curd
is transferred into perforated moulds of different shapes and sizes
to continue whey expulsion or draining. Pressing is usually
reserved for hard and semi-hard cheeses, but semi-soft cheeses are
also lightly pressed. Cheeses are sprinkled or rubbed with salt or
put in a brine bath. Salt acts as an antiseptic and also
contributes to skin or rind formation and flavouring. Finally, cheese can be waxed and sealed with Penicillium, or bacteria. It can also be washed in water, alcohol or brine. The cheese may also be covered with wood ashes, herbs, oil, or it can be smoked or painted like Port-Salut and Saint-Paulin.
Ripening is a process by which the constituents of milk are further broken down to produce the required flavour, texture and aroma of a specific cheese. This delicate procedure requires an environment in which moisture, temperature and oxygen are controlled to promote maturation. There are two principal ripening methods that can be used.
Non-surface ripening
Ripening begins and continues homogenously from the inside of the cheese mass outwards. The cheese is later hermetically sealed or coated with wax to prevent the action of oxygen on its surface. Swiss cheeses with curd-hole formation and Cheddars are examples of non-surface ripened cheeses.
Surface ripening
Surface ripening begins on the outside of the cheese and progresses inwards. Micro-organisms are added to the surface of the cheese to promote skin or rind formation. Bloomy-rind and washed-rind cheeses are surface-ripened.