Background
Butter is a soft, yellow-hued, edible emulsion of butterfat, water, air, and sometimes salt. It is made by churning cream and is used as a spread as well as an important ingredient in cooking and baking. Margarine is an inexpensive alternative to butter, made from oil or a combination of oils through the process of hydrogenation. Many people prefer margarine over butter because it is lower in fat and cholesterol than butter.
Butter
References to butter date back to as early as the ninth century B.C. in India, but its “invention” is credited to the nomadic tribes of Asia around 3500 B.C., although the first batch probably came about by accident. It is assumed that when the people of these tribes strapped bags containing milk onto their persons or saddles as nourishment for a journey, the motion of the ride churned the milk. If the weather was cold enough, a bit of fat rose to the top of the bag and the result came to be butter. On the other hand, if the weather was too warm, the result was what came to be cheese. The use of butter eventually spread westward when these Asian peoples invaded the lands of the Near East and Europe.
Eventually, butter began to be manufactured in vertical churns by other developed civilisations. A picture of a primitive churn is evident in a Sumerian bas-relief dating from around 3500 B.C. One of the first written references to the substance comes from India in the form of a ninth-century etiquette manual. It suggested that Hindu brides be given milk, honey, and butter on the day of their wedding. The manuscript also mentioned greasing the wheel of the bridal carriage with butter to ensure a trouble-free marriage. Because the cow is regarded as a sacred animal in the Hindu religion, butter has long played an important role in Indian cuisine and is mentioned specifically in religious tracts. In neighbouring Tibet, butter made from the milk of yak was sometimes smeared on religious statues.
Soon butter became common to cultures that relied on the domesticated cow for sustenance, but it could also be made from the milk of sheep and goats. Although Greeks and Romans were not fond of rich, dairy-based foods, the word “butter” is derived from the Greek term boutyron, meaning “cow’s cheese.” The term later found its way into Latin as butyrum. Celts and later the Vikings eventually became devotees of the substance, and by the late Middle Ages it was a staple in the diets of many Europeans and a valued trading commodity. The dairy product has also been considered a mystical salve during certain periods of history. For centuries, the people of Brittany placed butter near a person suffering from cancer to absorb the disease.
The first printed instructions for making butter can be traced back to a 14th-century Venetian cookbook. By the 17th century, butter was traded on routes that included England, Brittany, Flanders, and Iceland. The butter produced in Vanves, France, was thought to be the most exquisite during this era. In the southern regions of Europe, where olive oil remained the predominant cooking oil, some people believed butter caused leprosy. The dairy product eventually became a prohibited item for fast days as decreed by the Roman Catholic Church, although a dispensation could be purchased for those who simply could not go without it. In Rouen, France, legend has it that a “butter tower” was financed solely by such dispensations granted for eating butter on fast days.
Butter manufacturing in the United States dates from the time of the first colonists who brought cows with them to North America. Families who owned their own cows usually made butter themselves. Milk from the cow was left until its cream rose to the top. The cream was then skimmed off and left to cool, and the temperature was raised to about 70°F (21°C) a day before the butter-making process was to begin. Heating the cream ripened it, and it was then cooled several degrees. Next, the cream was placed in a wooden device, sometimes barrel-shaped or otherwise cylindrical, and mixed with the help of a paddle. This process generally took at least 30 minutes. The leftover cream in the churn was buttermilk. If the cows were eating grass, the butter possessed a yellowish cast, but during winter, when they were getting other types of feed, it was white. The butter was then rinsed with cool water, “worked over” a bit more, then salted for taste.
Margarine
Margarine is similar in taste and appearance to butter but possesses several distinct differences. Margarine was developed as a substitute for butter. By the 19th century, butter had become a common staple in the diet of people who lived off the land but was expensive for those who did not. Louis Napoleon III, a socialist-minded emperor of mid-century France, offered a reward to anyone who could produce an acceptable, affordable alternative. Hippolyte Mège-Mouriès won the 1869 competition for the item he named margarine after its primary ingredient, margaric acid. The margaric acid had only recently been discovered in 1813 by Michel Eugène Chevreul and derived its name from the Greek term for pearls, margaritēs, because of the milky drops that Chevreul noticed in his invention. In modern times it is manufactured from an oil or combination of oils through the process of hydrogenation, a method perfected around 1910. This process helps animal or vegetable oils emulsify, turning from a liquid into a semi-solid fatty substance.
In the United States, butter was the preferred taste for many years, and until relatively recent times margarine suffered from a poor brand image. A well-organised dairy cartel campaigned against margarine, fearing competition from the margarine industry. Around 1950, Congress repealed taxes on butter substitutes which had been in effect for several decades. The so-called “Margarine Act” was also heralded for at last defining margarine: “all substances, mixtures and compounds which have a consistency similar to that of butter and which contain any edible fats and oils other than milk fat if made in imitation or semblance of butter.” Part of margarine’s acceptance into the diets of Europeans and Americans came from rationing during times of war. Butter was scarce, and margarine—oleo—was the best substitute. Today, margarine has become a nearly interchangeable substitute for butter and provides less fat and cholesterol than butter at a lower cost.
Guidelines for margarine production dictate that margarine contain at least 80% fat. The oils used in the production can be derived from a variety of animal and vegetable sources. Its aqueous content may be milk, water, or a soy-based protein fluid.
The continuous-flow process is the most commonly used method in the manufacture of margarine. If milk is used as the liquid base, it is joined with salt and an emulsifying agent in a chamber. An emulsifier works by decreasing the surface tension between the oil globules and the liquid mixture, thereby helping them form chemical bonds more easily. The result is a substance that is neither wholly liquid nor wholly solid.
Since the 1930s, the Votator has been the most commonly used apparatus in U.S. margarine manufacturing. In the Votator, the margarine emulsion is cooled and occasionally agitated to form semi-solid margarine.
Raw Materials
Butter is made from dairy milk and salt. Margarine, on the other hand, can be made from a variety of substances. The first of these is any edible animal or vegetable oil such as corn oil or sunflower oil. Its liquid component can be milk, water, or sometimes a liquid protein mixture derived from soybean.
Butter Manufacture
Preparation
For many years the major creameries for butter manufacturing were located in the states of the Eastern Seaboard, but the flourishing of more industrialised agriculture in the Midwest led to the predominance of butter-making facilities there. The modern butter-making process begins when fresh cow’s milk from dairy farms is brought into the facility. The product is inspected, classified into different groups according to its adjudged quality, and then filtered to remove impurities. Then the milk is separated using centrifugal force. It is pumped into a large, cylindrical, vertical rotating device. When turned on, this rotor spins the liquid until the cream rises to the top. The cream is then fed into large stainless-steel vats or heat exchangers and heated to 180°F (82°C) for about 30 minutes in the pasteurisation process to remove any lingering bacteria. The pasteurised cream is then cooled.
Churning
The cream is placed in a large, mechanical churn usually made of aluminium. Some of these industrial-sized churns can make 1,500–5,000 lb (681–2,270 kg) of butter at a time. When the churn is activated, it tumbles the cream (much like the motion of a clothes dryer) while a worker watches the process through a small glass window on the churn. After about 45 minutes, small granules of butter begin to form, and the butter and buttermilk are separated. Salt is added, and the mixture is churned further. When this process is completed, a stainless-steel mobile device sometimes called a “boat” is placed adjacent to the opening of the mechanical churn. The door of the churn is opened, and the butter begins to spill out into the boat; activating the churn removes the rest. It is then wrapped into 64-lb (29 kg) cartons and sent to the distributor. There, the butter is repackaged for consumer and food-service use.
Margarine Manufacture
Margarine can be made from a variety of animal fats and was once predominantly manufactured from beef fat and called oleomargarine. Unlike butter, it can be packaged into a variety of consistencies, including liquid. Regardless of the form, margarine must meet strict government content standards because it can easily be confused with butter. These guidelines dictate that margarine be at least 80% fat, derived from animal or vegetable oils, or a blend of the two. Around 17–18.5% of the margarine is liquid, derived from either pasteurised skimmed milk, water, or soybean protein fluid. A small proportion (1–3%) is salt added for flavour, though some margarine is made and labelled salt-free. It must contain at least 15,000 units (U.S. Pharmacopeia) of vitamin A per pound. Other ingredients may be added to preserve shelf life.
Preparation
When the ingredients arrive at the margarine manufacturing facility, they undergo preparatory measures. The oil—safflower, corn, or soybean, among other types—is treated with a caustic soda solution to remove free fatty acids. The oil is then washed by mixing with hot water, separated, and dried under a vacuum. Next, the oil is sometimes bleached with a mixture of bleaching earth and charcoal in another vacuum chamber. The bleaching earth and charcoal absorb unwanted colourants and are then filtered from the oil. Whatever liquid is used—milk, water, or a soy-based substance—it too must be prepared. It undergoes pasteurisation to remove impurities, and if dry milk powder is used, it is checked for bacteria and other contaminants.
Hydrogenation
The oil is then hydrogenated to achieve the correct consistency for margarine production, a state referred to as “plastic” or semi-solid. In this process, hydrogen gas is added to the oil under pressure. The hydrogen bonds raise the melting point and make the oil less susceptible to oxidation.
Combining the ingredients
If milk is used as the liquid base, it is joined with salt and an emulsifying agent in a chamber. The emulsifying agent ensures that emulsification—chemically defined as a suspension of small globules of one liquid in a second liquid—takes place. An emulsifier works by decreasing the surface tension between the oil globules and the liquid mixture, thereby helping them form bonds more easily. The result is a semi-solid substance. Lecithin, a natural fat derived from egg yolk, soybean, or corn, is a typical emulsifier used in margarine manufacturing.
In the initial step, the liquid, salt, and lecithin are mixed in one tank opposite another vat holding the oils and oil-soluble ingredients. In the continuous-flow process, the contents of the two vats are fed on a timed basis into a third tank, typically called the emulsification chamber. While blending, sensors and regulators keep the mixture’s temperature near 100°F (38°C).
Agitation
Next, the margarine mixture is sent to a device called a Votator. In the Votator, the emulsion is cooled in Chamber A, which is divided into three tubes that successively decrease its temperature. Within two minutes the mixture reaches 45–50°F (7–10°C). It is then pumped into Chamber B, where it is occasionally agitated but generally left to set to its semi-solid state. If whipping or a special consistency is required, the agitation is done in Chamber B.
Quality Control
Quality control is a critical concern at modern food-processing facilities. Unclean equipment and poor methodology can lead to bacterial contamination. The U.S. Department of Agriculture maintains specific industrial hygiene codes for creameries and margarine plants. Inspections and fines for poorly maintained equipment or unclean conditions help keep companies in compliance.
Butter is graded by USDA inspectors at the creamery. They inspect each batch, test it, taste it, and assign a score to it: a maximum of 45 points for flavour, 25 for body and texture, 15 for colour, 10 for salt content, and 5 for packaging. A perfect batch would score 100, but typically the highest number assigned is 93. At 93, butter is classified and labelled Grade AA; a batch that scores below 90 is considered inferior.
Guidelines for margarine production dictate that margarine contain at least 80% fat. The oils used can be derived from a variety of animal and vegetable sources but all must be fit for human consumption. Its aqueous content may be milk, water, or a soy-based protein fluid. It must be pasteurised and contain at least 15,000 units of vitamin A. It may also contain a salt substitute, sweeteners, fatty emulsifiers, preservatives, vitamin D, and colouring agents.