Curdling
A required step in cheesemaking is separating the milk into solid curds and liquid whey . Usually this is done by acidifying ( souring ) the milk and adding rennet . The acidification can be accomplished directly by the addition of an acid like vinegar in a few cases ( paneer , queso fresco ), but usually starter bacteria are employed instead. These starter bacteria convert milk sugars into lactic acid . The same bacteria (and the enzymes they produce) also play a large role in the eventual flavor of aged cheeses. Most cheeses are made with starter bacteria from the Lactococci , Lactobacilli , or Streptococci families. Swiss starter cultures also include Propionibacter shermani , which produces carbon dioxide gas bubbles during aging, giving Swiss cheese or Emmental its holes.
Some fresh cheeses are curdled only by acidity, but most cheeses also use rennet. Rennet sets the cheese into a strong and rubbery gel compared to the fragile curds produced by acidic coagulation alone. It also allows curdling at a lower acidity—important because flavor-making bacteria are inhibited in high-acidity environments. In general, softer, smaller, fresher cheeses are curdled with a greater proportion of acid to rennet than harder, larger, longer-aged varieties.
Curd processing
At this point, the cheese has set into a very moist gel. Some soft cheeses are now essentially complete: they are drained, salted, and packaged. For most of the rest, the curd is cut into small cubes. This allows water to drain from the individual pieces of curd.
Some hard cheeses are then heated to temperatures in the range of 35–55 °C (95–131 °F). This forces more whey from the cut curd. It also changes the taste of the finished cheese, affecting both the bacterial culture and the milk chemistry. Cheeses that are heated to the higher temperatures are usually made with thermophilic starter bacteria which survive this step—either lactobacilli or streptococci .
Salt has roles in cheese besides adding a salty flavor. It preserves cheese from spoiling, draws moisture from the curd, and firms cheese’s texture in an interaction with its proteins . Some cheeses are salted from the outside with dry salt or brine washes. Most cheeses have the salt mixed directly into the curds.
Other techniques influence a cheese's texture and flavor. Some examples:
- Stretching: ( Mozzarella , Provolone ) The curd is stretched and kneaded in hot water, developing a stringy, fibrous body.
- Cheddaring : ( Cheddar , other English cheeses) The cut curd is repeatedly piled up, pushing more moisture away. The curd is also mixed (or milled ) for a long time, taking the sharp edges off the cut curd pieces and influencing the final product's texture.
- Washing: ( Edam , Gouda , Colby ) The curd is washed in warm water, lowering its acidity and making for a milder-tasting cheese.
Most cheeses achieve their final shape when the curds are pressed into a mold or form. The harder the cheese, the more pressure is applied. The pressure drives out moisture—the molds are designed to allow water to escape—and unifies the curds into a single solid body.
Aging
A newborn cheese is usually salty yet bland in flavor and, for harder varieties, rubbery in texture. These qualities are sometimes enjoyed— cheese curds are eaten on their own—but normally cheeses are left to rest under controlled conditions. This aging period (also called ripening, or, from the French, affinage ) lasts from a few days to several years. As a cheese ages, microbes and enzymes transform texture and intensify flavor. This transformation is largely a result of the breakdown of casein proteins and milkfat into a complex mix of amino acids , amines , and fatty acids .
Some cheeses have additional bacteria or molds intentionally introduced before or during aging. In traditional cheesemaking, these microbes might be already present in the aging room; they are simply allowed to settle and grow on the stored cheeses. More often today, prepared cultures are used, giving more consistent results and putting fewer constraints on the environment where the cheese ages. These cheeses include soft ripened cheeses such as Brie and Camembert , blue cheeses such as Roquefort , Stilton , Gorgonzola , and rind-washed cheeses such as Limburger .
Types
Factors in categorization
Factors which are relevant to the categorization of cheeses include:
- Length of aging
- Texture
- Methods of making
- Fat content
- Kind of milk
- Country/Region of Origin
List of common categories
No one categorization scheme can capture all the diversity of the world's cheeses. In practice, no single system is employed and different factors are emphasised in describing different classes of cheeses. This typical list of cheeses includes categories from foodwriter Barbara Ensrud. [ 13 ]
- Fresh
- Whey
- Pasta filata
- Semi-soft
- Semi-firm
- Hard
- Double and triple cream
- Soft-ripened
- Blue vein
- Goat or sheep
- Strong-smelling
- Sharp
- Processed
Fresh, whey and stretched curd cheeses
The main factor in the categorization of these cheese is their age. Fresh cheeses without additional preservatives can spoil in a matter of days.
For these simplest cheeses, milk is curdled and drained, with little other processing. Examples include cottage cheese , Romanian Caş , Neufchâtel (the model for American-style cream cheese ), and fresh goat's milk chèvre . Such cheeses are soft and spreadable, with a mild taste.
Whey cheeses are fresh cheeses made from the whey discarded while producing other cheeses. Provencal Brousse , Corsican Brocciu , Italian Ricotta , Romanian Urda , Greek Mizithra , and Norwegian Geitost are examples. Brocciu is mostly eaten fresh, and is as such a major ingredient in Corsican cuisine, but it can be aged too.
Traditional pasta filata cheeses such as Mozzarella also fall into the fresh cheese category. Fresh curds are stretched and kneaded in hot water to form a ball of Mozzarella, which in southern Italy is usually eaten within a few hours of being made. Stored in brine, it can be shipped, and is known worldwide for its use on pizzas. Other firm fresh cheeses include paneer and queso fresco .
Classed by texture
Categorizing cheeses by firmness is a common but inexact practice. The lines between "soft", "semi-soft", "semi-hard", and "hard" are arbitrary, and many types of cheese are made in softer or firmer variations. The factor controlling the hardness of a cheese is its moisture content which is dependent on the pressure with which it is packed into molds and the length of time it is aged.
Semi-soft cheeses and the sub-group, Monastery cheeses have a high moisture content and tend to be bland in flavor. Some well-known varieties include Havarti , Munster and Port Salut .
Cheeses that range in texture from semi-soft to firm include Swiss-style cheeses like Emmental and Gruyère . The same bacteria that give such cheeses their holes also contribute to their aromatic and sharp flavors. Other semi-soft to firm cheeses include Gouda, Edam, Jarlsberg and Cantal. Cheeses of this type are ideal for melting and are used on toast for quick snacks.
Harder cheeses have a lower moisture content than softer cheeses. They are generally packed into molds under more pressure and aged for a longer time. Cheeses that are semi-hard to hard include the familiar Cheddar , originating in the village of Cheddar in England but now used as a generic term for this style of cheese, of which varieties are imitated worldwide and are marketed by strength or the length of time they have been aged. Cheddar is one of a family of semi-hard or hard cheeses (including Cheshire and Gloucester ) whose curd is cut, gently heated, piled, and stirred before being pressed into forms. Colby and Monterey Jack are similar but milder cheeses; their curd is rinsed before it is pressed, washing away some acidity and calcium . A similar curd-washing takes place when making the Dutch cheeses Edam and Gouda .
Hard cheeses — "grating cheeses" such as Parmesan and Pecorino Romano —are quite firmly packed into large forms and aged for months or years.
Classed by content
Some cheeses are categorized by the source of the milk used to produce them or by the added fat content of the milk from which they are produced. While most of the world's commercially available cheese is made from cows' milk, many parts of the world also produce cheese from goats and sheep, well-known examples being Roquefort , produced in France, and Pecorino Romano, produced in Italy, from ewe's milk. One farm in Sweden also produces cheese from moose's milk . [ 14 ] Sometimes cheeses of a similar style may be available made from milk of different sources, Feta style cheeses, for example, being made from goats' milk in Greece and of sheep and cows milk elsewhere.
Double cream cheeses are soft cheeses of cows' milk which are enriched with cream so that their fat content is 60% or, in the case of triple creams, 75%.
Soft-ripened and Blue-vein
There are three main categories of cheese in which the presence of mold is a significant feature: soft ripened cheeses, washed rind cheeses and blue cheeses.
Soft-ripened cheeses are those which begin firm and rather chalky in texture but are aged from the exterior inwards by exposing them to mold. The mold may be a velvety bloom of Penicillium candida or P. camemberti that forms a flexible white crust and contributes to the smooth, runny, or gooey textures and more intense flavors of these aged cheeses. Brie and Camembert , the most famous of these cheeses, are made by allowing white mold to grow on the outside of a soft cheese for a few days or weeks. Goats' milk cheeses are often treated in a similar manner, sometimes with white molds (Chèvre-Boîte) and sometimes with blue.
Washed-rind cheeses are soft in character and ripen inwards like those with white molds; however, they are treated differently. Washed rind cheeses are periodically cured in a solution of saltwater brine and other mold-bearing agents which may include beer, wine, brandy and spices, making their surfaces amenable to a class of bacteria Brevibacterium linens (the reddish-orange "smear bacteria") which impart pungent odors and distinctive flavors. Washed-rind cheeses can be soft ( Limburger ), semi-hard ( Munster ), or hard ( Appenzeller ). The same bacteria can also have some impact on cheeses that are simply ripened in humid conditions, like Camembert .
So-called blue cheese is created by inoculating a cheese with Penicillium roqueforti or Penicillium glaucum . This is done while the cheese is still in the form of loosely pressed curds, and may be further enhanced by piercing a ripening block of cheese with skewers in an atmosphere in which the mold is prevalent. The mold grows within the cheese as it ages. These cheeses have distinct blue veins which gives them their name, and, often, assertive flavors. The molds may range from pale green to dark blue, and may be accompanied by white and crusty brown molds. Their texture can be soft or firm. Some of the most renowned cheeses are of this type, each with its own distinctive color, flavor, texture and smell. They include Roquefort , Gorgonzola , and Stilton .
Processed cheeses
Processed cheese is made from traditional cheese and emulsifying salts, often with the addition of milk, more salt, preservatives , and food coloring . It is inexpensive, consistent, and melts smoothly. It is sold packaged and either pre-sliced or unsliced, in a number of varieties. It is also available in spraycans.
Source: wikipedia
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