In this article we will discuss about the steps involved in the manufacture of butter. The steps are: 1. Churning 2. Preparation of Cream 3. Preparation of Starter for Ripening the Cream 4. Ripening of Cream 5. Amount of Cream in Churn 6. Use of Colour 7. Breaking Stage in Churning 8. Washing the Butter Granules 9. Working of Butter 10. Salting 11. Keeping Quality.
1. Churning:
A vessel or device in which cream or milk is agitated to separate the oily globules from the caseous and serous parts, used to make butter.
Churning is the process of shaking up cream (or whole milk to make butter and various forms of butter churn have been used for the purpose. Butter is essentially the fat of milk. It is usually made from sweet cream.
Process of Churning:
1. Preparation of Churn and Other Appliances:
i. Before use, put some boiling water in churn and revolve it. It should, however, be ventilated frequently after it is set in motion. Revolving the churn with hot water in it and without ventilation may result in serious injuries to the worker.
ii. Next, rinse the churn with cold water and drain it off. Rub the inside of the churn with salt. Rinse again with cold water for a few times which should be a few degrees cooler than churning temperature. Leave some water in the churn until cream is ready to be put in. The hot water opens the pores of the wood and the cold water fills them, which prevents the butter from adhering to the wood.
iii. Just before adding the cream, revolve the churn briskly for a few minutes and then drain off the water. If the churn is new or is used at infrequent intervals, it should be kept filled with hot water for at least 24 h before use. A properly cleaned churn will have a fresh and fine odour. The wood should be free from grease.
iv. The butter worker and other appliances such as scotch-hand prints, etc., should be cleaned with warm water. Scrub the appliances thoroughly using a lime soda solution. Rinse with boiling water and leave them in a well- ventilated place. Place the appliances on racks for drying.
v. In very hot weather, make the appliances ready a few hour before use, so that they may have sufficient time to cool down. Keep the roller of the butter worker wrapped in a wet muslin cloth to keep it cool.
vi. Scrub all the appliances with a brush. Use only a good scrubbing brush. It should not have loose bristles.
2. Preparation of Cream:
After the cream is received, it is to be neutralised if sour, pasteurised, cooled and made ready for churning.
(i) Neutralisation:
If the cream for butter making is sour, it is essential to neutralise it. The neutralisation reduces the acidity in sour cream, thereby improves the flavour, texture and keeping quality. It helps to produce a butter of more uniform quality. In addition, neutralisation causes a saving by avoiding the loss of fat due to coagulation of casein, which takes place on heating the cream of relatively high acidity. It also prevents the occurrence of curd particles in butter made from sour cream.
Lime or soda is commonly used as a neutraliser. Lime is strong alkali; therefore, its use requires a great care. Soda is a weaker alkali and is, therefore, safer and easier to use. Among the commercial neutralisers, sodium bicarbonate or a mixture of sodium bicarbonate and sodium carbonate is common.
A mixture of hydrated lime (calcium hydrate) and magnesium oxide or a mixture of quick lime (calcium oxide) and magnesium oxide is also used. Whichever neutraliser is used, care should be taken to use it in correct strength and amount. The neutraliser should be added as a weak solution of the alkali used. It should neither be used in a dry or powder form and viscous or lumpy cream.
The neutraliser, specially the soda should be added slowly, particularly in a high acid cream to prevent it from forming up and running over. It is best to add the alkali solution by sprinkling it slowly over the surface of the cream, so that it is quickly dissipated to prevent over neutralisation of a portion of the cream.
If the neutraliser is not added in the collect manner, it may lead to the butter to have a neutraliser flavour. It may also result in an excessive loss of fat during the manufacture and a poor keeping quality of the resulting butter.
(ii) Pasteurisation:
Cream The main purpose of pasteurising cream for butter-making is to kill bacteria, yeast and moulds and to render enzyme inactive in cream. With efficient pasteurisation, 99% or more of the bacteria and almost all the yeasts and moulds present in the cream are destroyed. In addition, all the disease-producing bacteria are killed. The pasteurisation also helps in eliminating the feed or other flavours. Butter from a pasteurised cream is more uniform and has a high keeping quality.
But to get these benefits, the pasteurisation has to be done well. Using high temperature or holding the cream for long time at the pasteurisation temperature may cause a mealy texture and scorched flavour.
3. Preparation of Starter for Ripening the Cream:
The use of a suitable starter for ripening the cream helps to prevent the development of certain undesirable types of bacteria and to obtain a butter of a more desirable flavour and uniform quality.
To prepare the starter, the milk should be fresh and clean, having minimum number of bacteria. First heat the milk in a clean container, preferably of glass or stainless steel, by raising its temperature to 200°F and holding it at that temperature for one hour.
Then, cool the milk to the temperature of 70°F and inoculate it with the culture of bacteria obtained from a reliable source. To help the growth of bacteria, the milk should be kept at a uniform temperature of 70°F The starter at the end of the incubation period should have acidity of 0.75-0.80%. To retard the further growth of bacteria, it should be set away at low temperature ranging between 32°F-40°F.
4. Ripening of Cream:
Cream is ripened to improve the flavour and aroma and the keeping quality of the resulting butter. Ripening also reduces the loss of fat. The loss of fat in the buttermilk is much smaller when a ripened cream is churned than when an unopened cream is used. Cream should be ripened in a properly ventilated room. The surroundings and the utensils used should be clean to avoid any contamination by undesirable organisms.
A suitable starter should be used for inducing the collect form of ripening. Less starter is used during summer and more during winter. Use of 2-5% starter is sufficient for the ripening and the stirring of the cream should be done occasionally.
5. Amount of Cream in Churn:
The amount of cream to be put in the churn should be sufficient to receive proper agitation during churning. The best result is obtained when the churn is one-third to one-half full.
If there is little cream, during churning there may be a rapid rise in temperature of the cream which may result in a poor quality of butter.
If the churn is full and the stirring is inadequate, cream may cause prolonged churning and there will be an increase in the loss of fat in the butter milk. The body and texture of the butter obtained will be of inferior quality. Apart from this, the butter may have an uneven colour and composition.
6. Use of Colour:
A special colour extracted from annatto seeds commonly known as butter colour, is added to the cream to produce uniform appearance. Butter from buffalo milk is almost white, which needs more colouring material than the butter made from cow milk.
7. Breaking Stage in Churning:
As churning progresses, a stage is reached when the cream breaks i.e., when it becomes brittle.
This change can be noted by the following signs:
i. The sound of the cream falling in the churn changes to dull thud.
ii. The glass window in the lid of the churn is partially cleared.
iii. The cream becomes viscous and brittle.
iv. The buttermilk starts oozing out.
8. Washing the Butter Granules:
As soon as the butter granules are of the size of peas or jowar grains, the churning should be stopped and butter granules should be washed. The purpose of washing the butter granules is to remove the buttermilk that adheres to the surface of the granules and to inside surface of the churn.
Washing improves the keeping quality of the butter and also helps in controlling, to some extent, the body and texture of the butter. Objectionable flavours are removed by proper washing.
After draining away the butter add clean water to the churn for washing the butter granules. The temperature of the water added should be two or three degrees lower than the churning temperature. The quantity of water should be about the same as the quantity of the cream. Revolve the churn almost 8-10 times and then drain off the water.
9. Working of Butter:
Butter is worked to remove the surplus moisture and to bring the butter granules together to join a product with a compact body. Leaky butter favours the growth of moulds. Great care is needed in working the butter.
A good butter is often spoiled by the rough use of the roller at this stage. The number of times the butter should be worked or pressed will depend upon the room temperature and the size and hardness of the butter grains. As a rule, two workings are considered sufficient. Over working makes the butter pasty and spoils its texture, whereas under working allows excess of moisture to remain in the butter. While working care should be taken to avoid air holes in the butter.
10. Salting:
The main object of adding salt to butter is to improve its keeping quality by preventing the growth of bacteria, yeast and mould.
The exact quantity of salt to be added mainly depends upon the taste of the customers. Certain people like a high salt content, while the others prefer altogether an unsalted butter. Normally, 1.5-2.5% salt is considered to be adequate.
While adding salt, care should be taken for uniform distribution throughout the mass. If the salt is not uniformly distributed, it will cause grittiness, texture in the butter. It will also affect uniformity in the composition of the butter.
11. Keeping Quality:
Butter made from fresh cream with a low acidity contains minimum of moisture and curd, and a little salt may be expected to keep well up to one week at a temperature of about 75 to 80°F.
Butter made from poor quality sour cream, which contains 1 to 1.5% of curd and over 20% of moisture and is unsalted will go bad within 24-48h at a temperature between 75°F and 80°F.
Good quality butter kept under refrigeration at temperature of 15-20°F should keep for several months, although the low chemical determination which affects the flavour of butter may take place.
Precautions While Preparing Butter:
The following precautionary measures must be observed for the preparation of butter:
(i) The cream from which the butter is to be prepared should be clean and free from any undesirable odour taste and impurities.
(ii) Colostrum should never be used for butter making.
(iii) The place for making butter should always be kept clean.
(iv) The ceiling of it should be free from cobwebs, etc.
(v) There should be proper arrangement for the disposal of the effluent.
(vi) The surroundings should be kept clean and dry.
(vii) Sour cream or any other strong smelling product should not be kept near the butter. Butter-churn and other appliances should be thoroughly cleaned and sterilised.