The Specialist Cheesemakers Association - Code of Best Practice

2.1 The process of cheesemaking is based on lactic acid fermentation of milk. Specific bacteria or starter cultures are added to milk. This ferments the milk sugar and produces lactic acid. When sufficient acidity is produced, casein within the milk is coagulated, normally using rennet. The curd is then cut leaving a mixture of curds (the solid constituent) and whey (the liquid). After heating, liquid whey is drained off. The curds are then subjected to different processes, such as pressing, resulting in the production of cheese.

2.2 The recipe for a specific cheese should define the ingredients, their proportions and their quality, as well as the acidities and temperatures at each stage of the process. It should also describe the operations to be performed in the manufacturing process. Finally, the recipe should define the storage conditions for the ripening period.

2.3 There are many different traditional methods of manufacturing cheese and many varieties of cheese. They include hard pressed, blue veined, soft, and cream cheese. The variety of cheese is related to the type of milk, degree of acidity, type of starter cultures used, the length of ripening period and many other factors. Specialist cheeses in particular express the natural flavours of the milk supply. They reflect the breed of animal used and the pastures on which they graze. The following paragraphs outline the steps in the process carried out for a typical Cheddar type. However, examples of how other cheeses differ are included to indicate the range of varieties possible. Flow charts describing the basic cheesemaking process can be found at Annex A.

THE IMPORTANCE OF ACIDITY

2.4 Acidity is one of the major control factors in cheesemaking and is developed by adding a starter culture of lactic acid bacteria to milk. These bacteria ferment the sugar (lactose) present in the milk to produce lactic acid. Antibiotics, if present in the milk, will prevent the starter culture from producing the desired acidity. The appropriate amount of starter is added to the milk normally at a temperature of around 30^oC and the milk is stirred. Failure of the milk and the starter culture to develop acidity at a sufficient rate can result in allowing harmful or undesirable organisms to grow. It can also result in taint, high moisture, and a weak curd in the cheese. Too much acidity developing too quickly can result in cheese with poor body and texture.

2.5 The correct development of controlled acidity is critical to the good manufacture of cheese, and to inhibit the proliferation of harmful and spoilage organisms. It is important that cheesemakers monitor titratable acidities, develop a satisfactory acid development profile unique to their circumstances, and take corrective action if future deviations occur. This helps to verify good process control, and provides important evidence for both manufacturers and Food Authorities. Specimen values are not given here, since variations occur according to many factors. The recipe, the type of milk used, the type of starter used, and even the season of the year may all affect acidity. Seek advice from the SCA if you are in any doubt.

STARTER CULTURES

2.6 Starter cultures can be made up as a bulk starter, or purchased as a Direct to Vat Inoculation (DVI). A bulk starter involves using a small amount of the starter culture which is then fermented through various stages. This produces a larger volume of bulk starter which is then used to inoculate the milk. DVI starter culture is available in more concentrated forms and can be added directly to the milk. These starter cultures come in freeze dried or frozen form. Freeze dried starters are now commonly used as they can be stored for up to 6 months in a normal domestic type freezer at minus 18^ºC.

CHEESE MADE WITHOUT STARTER

2.7 Some cheeses are traditionally made without a starter. Milk is left to sour by naturally occurring bacteria. This process involves holding milk at a temperature of about 27^ºC to 30^ºC until it reaches the correct acidity for the addition of rennet. This process is not considered to be good practice, as holding the milk at this temperature is ideal for the growth of harmful bacteria. It is therefore good practice for cheesemakers to use a starter, as otherwise there is no control over the process, and there will be no consistency in the final product.

USE OF LIVE NATURAL YOGURT AS A STARTER

2.8 It is possible to use live natural yogurt as a starter. While this is arguably better than using no starter at all, it may still be difficult to control the process. Therefore, it is good practice to use a recognised starter culture. The SCA does not recommend the use of yogurt as a starter.

COLOURING

2.9 Certain recipes call for the use of colouring. Annatto and Carotene are two of the most frequently used. Colouring is added after the starter, but before the rennet. The amount used will vary according to the recipe, the colour desired, and the manufacturer's instructions for use.

RENNET

2.10 Rennet is a coagulant traditionally obtained from calf's stomach. Rennet substitutes, such as vegetarian rennet, are now mainly used. It is added to the milk once the correct acidity is reached, approximately 45 minutes after addition of the starter. For Cheddar cheese, rennet should be added at a temperature of around 32^ºC, whereas most goat cheeses require a temperature of 23^ºC. Rennet should be stored in a dark container and kept in a cool place or preferably under refrigeration.

SETTING AND CUTTING THE CURD

2.11 Once the rennet has been added, the curd is left to set and to achieve the acidity desired for that particular type of cheese. When the curd is set, it is then usually cut into small pieces, either by machine or by hand, in order to release the whey.

SCALDING AND STIRRING

2.12 This process helps to determine the texture of the cheese. It involves slowly raising the temperature of the curds and whey while stirring. For Cheddar cheese the temperature is usually increased to around 39^ºC within approximately 30 to 45 minutes.

PITCHING AND RUNNING THE WHEY

2.13 The curds are then allowed to settle to the bottom of the vat or container (pitching). As much of the whey as possible is either drained off or ladled out, leaving only the curds. The curds are then normally either left in the vat or put into a suitable perforated container and left to drain.

STACKING OR CHEDDARING

2.14 Stacking or cheddaring is used to drain off more of the whey and to help give the cheese the required texture. It also helps to develop the acidity. When the drained curds have formed a mass, they are then cut into slices which are stacked on top of one another. The curds are turned and stacked several times during this process which generally takes around one and a half to two hours.

MILLING

2.15 This is the process of breaking the curds into small pieces so that they can be pressed together in moulds or hoops (sometimes known as chessles) to the required shape and size of the cheese. This can be done either using a special mechanical mill or by hand.

SALTING

2.16 Salt is added to the milled curds. It acts as a flavour enhancer and a preservative, and also helps to control acid development. It is thoroughly mixed in and allowed to stand for a short time. Some cheeses are salted by placing in a brine solution after pressing, e.g., traditional Caerphilly, or the Edam and Gouda types, and some are dry salted on the outside only.

MOULDING OR HOOPING AND PRESSING

2.17 The salted and mixed curds are then placed into moulds or hoops, which determine the finished shape of the cheese. The curds are then pressed gradually to allow the remaining whey to drain slowly. This ensures that there is no excessive fat loss within the whey: loss of fat reduces the yield and changes the nature of the cheese. The time under pressure and the weight used will vary with the size and type of cheese. Brie and Camembert type cheeses need a minimum temperature of 25^oC and 90 - 95% humidity in the moulding room.

2.18 Cheese moulds are usually made from either stainless steel or food grade high density plastic. They normally have a fused base and are perforated to allow drainage of the whey as the cheese is being pressed. The term 'hoop' is used for any curd container without a fused base. These containers are normally used for cheeses which do not need to be pressed.

USE OF MUSLIN AND BANDAGING

2.19 Muslin is sometimes used to line moulds or hoops prior to the addition of the curds. After pressing, the muslin is often removed from the cheese after a few days. Bandaging is normally carried out immediately after cheese has been pressed and prior to maturing. Bandaging is not normally removed until the cheese has fully matured.

MATURING OR RIPENING

2.20 Most cheeses need to be matured or ripened before being sold, e.g., Cheddar types and blue veined types such as Stilton. Some fresh cheeses are sold without going through a maturing or ripening stage, e.g., Cottage cheese, Crowdie.

2.21 Cheeses to be matured are placed on shelves in a maturing room at a temperature and humidity suited to that particular cheese. It is good practice to ensure that there is adequate ventilation during the storage of this type of cheese. Blue veined cheeses require a high humidity during the maturing period to encourage the growth of their distinctive moulds.

2.22 The time taken to mature depends on the variety of cheese and the desired texture. Soft mould ripened cheeses mature for about 1 month before being wrapped for distribution. Other cheeses may take around 3 months, e.g., Blue Cheshire or a mild Cheddar, to a year or even longer. In the case of Parmesan type cheese, the maturing period is at least one year and up to four. Some cheeses may also be bandaged (e.g., traditional Cheddars and some traditional farmhouse Cheshires), larded (traditional Cheddars), or waxed (e.g., farmhouse Gouda, Mull of Kintyre, Isle of Gigha) before being allowed to mature.

2.23 Cheese should always be placed on dry, clean shelves and the air allowed to circulate freely. Cheese should be turned as required to ensure even moisture distribution within the cheese, even evaporation, and also to prevent sticking to the shelves.

FURTHER INFORMATION

2.24 Not all possible variations of cheesemaking can be covered here. Each cheesemaker will follow their own tried and trusted recipes and procedures. Ultimately, the skills of the traditional cheesemaker are used to produce quality traditional products. The experienced cheesemaker will be able to assess variations in the milk and the feel of the curd and if necessary make changes to the method of handling, in order to produce quality cheese. If you are looking for a particular recipe, seek advice from the SCA.

Specialist Cheesemakers Association 17 Clerkenwell Green London EC1R 0DP

Tel: 020 7253 2114 Fax: 020 7608 1645 Email: info@specialistcheesemakers.co.uk