Module 14. Packaging, storage and distribution of cheese

Lesson 30


30.1 Introduction

After completion of the post-processing treatments like bandaging and dressing, the cheeses are kept in the ripening room. This starts the process of ripening. For some varieties of cheese like Cheddar and Parmesan, ripening and storage are the same while for others like Camembert and Roquefort, ripening and storage are two different processes as they need altered temperature and humidity in both the processes. Storage is inevitably, a continuation of the ripening process (except changing temperature and humidity for some varieties) so that all the considerations which apply to the ripening period apply equally to the storage period.

30.2 Shelves for Ripening/Storage of Cheese

In traditional practice, wood was used as the material for construction of shelves. But it has many disadvantages like it gives shelter to pests and is an excellent medium for the growth of molds and other microorganisms, once it is wet. So, wooden shelves need lot of care and maintenance. The easiest materials to clean are glass and stainless steel.

30.3 Factors Affecting Ripening and Storage

The two most important factors controlling ripening and storage are temperature and humidity. Thus the ripening or storage rooms should have means for controlling these two factors.

30.3.1 Temperature

It is necessary to control the temperature during storage and maintain uniform temperature as almost all biochemical reactions are temperature-dependent. Higher temperature accelerates ripening but jeopardizes the quality of cheese as it results in the growth of undesirable microorganisms. For cheeses of Cheddar and related varieties, temperature of 5-7°C is ideal but 8-12°C is considered economically best. Temperature higher than 18°C should be strictly avoided.

30.3.2 Humidity

The relative humidity of a gas is the amount of water vapour present expressed as percentage of that required to saturate the gas. Higher humidity leads to mold growth, accelerated ripening and surface bacterial taints. Lower humidity results in cracking, shrinking, distortion and retardation of ripening in addition to excessive loss of weight. The correct humidity for ripening depends on the type of cheese. Soft cheese requires a higher humidity (95%) than open-textured hard cheese (85%) and these again require greater humidity than close-textured hard cheese (80%). Further, mold ripened cheese require higher humidity than other varieties of cheese.

30.4 Storage Conditions for some of the Cheese Varieties

Cheeses of the Cheddar family (Cheddar, Cheshire, etc.) are ripened at lower temperatures of about 4-8°C, and a relative humidity (RH) lower than 80%. The ripening time may vary from a few months up to 8–10 months or even 12 months.

Other types of cheese like Emmental are first stored in a ‘green’ cheese room at 8–12°C for some 3–4 weeks followed by storage in a ‘fermenting’ room at 22–25°C for some 6–7 weeks. After that the cheese is stored for several months in a ripening store at 8–12°C. The relative humidity in all rooms is normally 85–90%.

Smear-treated types of cheese – Tilsiter, Havarti and others – are typically stored in a fermenting room for some 2 weeks at 14–16°C and a RH of about 90%, during which time the surface is smeared with a special cultured smear mixed with a salt solution. Once the desired layer of smear has developed, the cheese is normally transferred to the ripening room at a temperature of 10–12°C and a RH of 90% for a further 2–3 weeks. Eventually, after the smear is washed off and cheese is wrapped in aluminium foil, it is transferred to a cold store, 6–10°C and about 70–75% RH, where it remains until distributed.

Other hard and semi-hard types of cheese, Gouda, Edam, may first be stored for a couple of weeks in a ‘green’ cheese room at 10–12°C and a RH of some 75%. After that a ripening period of about 3–4 weeks may follow at 12–18°C and 75–80% RH. Finally the cheese is transferred to a storage room at about 10–12°C and a relative humidity of about 75%, where the final characteristics are developed.

30.5 Factors Controlling the Loss of Moisture in Cheese

The primary factors which control the loss of moisture in cheese are temperature, moisture content, size and shape of the cheese and RH of air. The rate of loss of moisture rises sharply with temperature. With storage at 5, 10 and 15°C, the losses in 6 months were found to be 4.4, 6.4 and 8.7%, respectively. Higher the moisture content, higher will be the rate of loss and more is the free moisture. The smaller the cheese, the more rapid the losses of moisture as a proportion of that initially present. The higher the RH of the air in the cheese storage room, slower will be the rate of moisture loss.

Other factors that influence the loss of moisture during storage are type and quality of the wax or film applied to the outside of the cheese and type of cheese.

30.6 Distribution of Cheese

Distribution of cheese from manufacturer to distributor/retailer should be done under strict conditions of appropriate temperature. For cheese varieties, which continue to ripen in the storage period, it is important to maintain the temperature for ripening during distribution also. For example, Cheddar cheese should be distributed at the temperature of 5-8°C. Refrigerated and insulated vehicles are used for this purpose.

Last modified: Wednesday, 3 October 2012, 10:32 AM