Cheesemaking is an area of food hygiene that requires particular attention to cleaning. It is not enough to use ordinary detergents in cheesemaking, special detergents are sold to dairies by their dairy products suppliers. This includes the chemicals used for cleaning the pasteurising machines. In fact, a good cheesemaker spends around 50% of his time cleaning.
Cheese can only be made in vats that can tolerate being washed in caustic soda. This means that the only metal that can be used is stainless steel. All vats and stainless steel work surfaces must be washed after each job, after the end of the working day and before work begins in the morning. This also includes milk holding tanks and their pipes which are washed in an internal washing system using caustic soda in water that is heated to 65-70 degrees Centigrade.
The soda is sprayed into the tank by a pump via a rotating sprinkler. After the cycle has worked for the correct period the soda is sent into the drain, the tank is then sprayed by hand to get rid of all soda residue, including sending some through the sprinkler, then filled with an adequate quantity of fresh water which is pumped through the pipes to wash out any soda remaining in them. The pasteuriser is also undergoes CIP (cleaning in place), as soon as the milk has been pasteurised and also at the beginning of every working day before milk is passed through it to be pasteurised.
Cheese dairies usually only work making one type of cheese. However, some “boutique” dairies make a selection of cheeses. It is important to keep the production of cheese that incorporate the use of molds well away from cheeses that do not have molds in them because because it is almost impossible to prevent mold cross contamination. Even a single mold spore in a block of maturing cheese can cause it to go runny and take on entirely different characteristics from those desired and the whole maturation room will be infected with cheese mold spores.
If you make cheeses remember these principles. When making cheeses nothing else should be in the area during the whole process. Personal hygiene is of utmost importance. Hands washed to the elbow in very hot water and detergent, no rings, no watches, no bracelets. Wear gloves whenever handling milk products and change gloves if they are surgeons gloves or wash them frequently in hot water and detergent if they are not disposable ones.
A number of people have contacted me in request that I give some information about sterilizing cooking pots and other kitchen utensils. For most of us in the western world it is not absolutely necessary to sterilize pots as long as we make sure that we wash them thoroughly in very hot water and washing up detergent and a scrubbing pad. In other areas of the world or in situations where pots have been out in field conditions for any period of time, especially in areas where disease is prevalent, the need to continually sterilize pots may be a critical factor in the prevention of food contamination and the recontamination of sick people and the promotion of food hygiene in areas where it does not exist.
Firstly we need to look at the different types of cooking pots. The easiest type of kitchen cooking utensil to sterilize is stainless steel because we can clean it chemically without changing its properties. Other forms of pots present more problems. In Africa it is very common to cook in what, in some places, is called a “poike”. If I am not mistaken this is an Afrikaans word for a cast iron cooking pot. It is cast from a thick sheet of iron or steel and is designed to sit over an open fire. They come in many different sizes and are usually very heavy indeed. They have usually been treated with blackening so they have an outer covering. They also have a thick metal carrying handle that is attached to the rim of the pot across its diameter.
Another form of cooking pot is the aluminum pot. the advantages of aluminum are that it is lightweight and heats up very quickly. The disadvantages of aluminum are that it reacts to just about every form of chemical used to sterilize kitchen equipment. Even the acid in tomatoes, lemon and eggplants remove the essential oxidized layer on aluminum pots. The metal is relatively weak and handles usually fall off after a period of use.
Copper is another form of metal use to make cooking pots but utensils made from copper are normally expensive and in my opinion would not be used in areas of the world which require the sterilization of cooking equipment. In any case we can class it as having very similar properties to aluminum from a cleaning perspective.
Probably the oldest and most traditional way to sterilize all forms of cooking equipment is to boil them in boiling water. Adding some salt to the water will help in the disinfecting process and it will slightly increase the boiling temperature of the water and destroy more bacteria. The advantage of this system is that the pots and pans are immediately ready for use after sterilization. The disadvantages are that the equipment has to be 100% clean before going into the sterilization pot and they require a minimum of thirty minutes to boil before it is safe to take them out. Boiling does not ensure that all types of bacteria will be destroyed and some toxins can survive boiling.
Continuing with the theme of using water to sterilize kitchen equipment another efficient way to sterilize pots and pans is with steam. Steam is much hotter than water it will sterilize things that come into contact with it much more quickly. Using steam under pressure also removes baked on fats and other sediments. Steam treatment is OK for all types of metals but Steam is dangerous and requires that special equipment be worn before working with it safely and efficiently. This equipment should include thick plastic apron, thick plastic or neoprene gloves (not surgical gloves) and eye protection goggles. Like with water the advantage of steam is that equipment can be put straight back into use with no further treatment other than washing with a mild detergent and rinsing with water.
Caustic Soda is the next form of sterilization which I would like to talk about. Caustic Soda destroys all forms or organic material. Concentrated caustic soda needs to be diluted with water and heated to a temperature of no more than 80 degrees Celsius. Caustic soda breaks down at temperatures above 80 degrees Celsius and ceases to be effective.
Great care must be taken with caustic soda because it is very dangerous and can cause serious burns and blindness if it gets into your eyes. People using caustic soda should be properly trained and should also wear protective clothing which should include a thick plastic apron, thick neoprene gloves and a full industrial plastic face mask. This chemical is only suitable for stainless steel, plastic and glass. Other forms of metal will be affected by the chemical reaction of the soda. Aluminum may even be eaten away completely.
The use of caustic soda is also good for removing stubborn cooked on foods. The disadvantage of using soda is that it needs to be washed off dishes completely before they can be used again. Most big kitchen will use a high pressure tray washing machine to do this. If your water supply is not infected you may want to consider rinsing the pots in boiling water to avoid re contamination.
Caustic soda melts the fat in your skin if it spills onto the skin and it causes a slimy film on the surface of the skin until it is properly washed off with cold water. Wash until this feeling has completely gone. Caustic soda is also good for cleaning glass, ceramic and plastic utensils.
Yet another method of sterilizing kitchen equipment is to soak it in hot water and chlorine cleaning powder. Chlorine kitchen powder is also good for removing stubborn stains on ceramics, glass and Pyrex. This type of sterilization will react with aluminum and will remove the oxidized lawyer on the surface of the aluminum which is necessary to remove the toxicity of aluminum. Pots may become unusable if exposed to chlorine powder; therefore, I do not advise using chlorine powder to sterilize aluminum
This form of sterilization requires that equipment be soaked for about three to four hours for good results. Similarly to the use of chlorine must be washed off completely with a mild detergent before reusing treated equipment.