Many different combinations of vegetable oils and fats are used to create a wide range of margarine and spread products that today's consumer uses. For example, sunflower and olive oils are used to help give consumers a healthier choice. To help improve the nation's diet some products contain less fat. For optimum baking performance a completely different set of characteristics are needed.

These varied characteristics are achieved by mixing liquid vegetable oils and vegetable fats. The vegetable fats are hard and mixing them into the liquid oils in different proportions gives this wide variety of outcomes.

Suitable natural hard fats are not widely available so it has been necessary to create them by different vegetable oil modification processes. These are part of the oil refining process that takes place before the oils are mixed to make a margarine or spread blend.

No single process technique can meet all these needs. Instead three different oil modification processes are used. All have been in wide use for this purpose for over 80 years.

Two are concentration techniques, which use the natural hardness present in some oils. The last creates hardness by directly modifying oils through a chemical process.
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Fractionation or Separation

This process concentrates the hardness by cooling the oils. As the oil cools the harder part starts to crystallise and separate out from the softer part. This is then filtered out to give a concentrated fat harder than the original oil, leaving behind an oil softer than the original oil. Unfortunately few oils are suitable for this process.
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Rearrangement or Inter-Esterification

Some oils and fats that have some natural hardness cannot be concentrated like the above so a different technique is used. In these oils the hardness is spread thinly between individual molecules. By using a combination of high temperature and pressure this hardness can be concentrated in fewer molecules making them quite hard, and the whole oil harder than before. By putting different oils together during this process it is possible to create a wide range of products with different degrees of hardness.
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Hardening or Hydrogenation

This is a process that alters the individual molecules of an oil to make them harder. It can be applied to any oil and is particularly useful for those oils that have no natural hardness. The natural gas hydrogen is added to the oils under pressure and at high temperature. This reacts with the soft parts of the oil molecules to make them harder.

By adding different amounts of hydrogen different degrees of hardness are created, ranging from the really very hard to an oil that has just been slightly thickened.
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Catalysts

The last two processes are normally quite slow so they are helped to speed up by the use of catalysts. These are ingredients that are added into the processes that speed them up by assisting the changes to take place, and are then removed before the finished harder products are put in storage. They are absent from the finished products.

Mixtures of these techniques are used to give different benefits or advantages to the consumer. In fact without these techniques it would be impossible to give today’s consumers the wide range of choice they have come to expect from their suppliers of margarine and spreads.
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Outlined in the table below is an illustration of the manufacturing, packing and distribution process of margarine and spreads.