Mad about Science: Butter

By Benden Bobby
Reader Columnist

Most carb-heavy cuisine is enhanced by the addition of butter. Smooth, creamy, melty goodness that clogs up your arteries and triggers salivation. It is a unique culinary creation that acts as a solid until heat converts it into something akin to liquid oil. The behavior of butter makes it easy to store for long periods of time under refrigeration, without fear of spilling and creating a mess like other liquids and oils.

Have you ever wondered where butter comes from? Cows, obviously!

Butter begins as milk harvested from dairy cows. The quality of milk can change based on how the cow is feeling — a happy cow produces more milk, while a stressed or sad cow may produce very little or none at all. Most, if not all dairy cows are mothers that actively feed their calves between milkings.

Milk is transported from the farm to a production facility via refrigerated trucks. It’s likely you’ve seen a number of these trucks cruise through town with large cylindrical chrome tanks on the back. These containers are specifically designed to transport milk, and it needs to go from farm to facility in under 24 hours. If you spend any time on Baldy Mountain Road or Division Street, it’s likely you’ve seen some of these trucks heading to or from the Litehouse Foods facility.

Once at the processing facility, the milk is tested for a number of factors, including the presence of bacteria or other contaminants, as well as quality and fat content. If milk taste-tester is your dream gig, I’m sorry to disappoint you, but this is done almost exclusively with equipment and chemicals to avoid accidental poisonings. If the batch is cleared and deemed safe by federally mandated standards, as well as the manufacturer’s standards, it moves on to the next step of the process.

The milk next undergoes a process called ultra-high temperature pasteurization. This occurs by heating the milk to a temperature of 280 degrees Fahrenheit to sterilize the milk of any and all bacteria. Anyone paying attention during science class would know that water becomes steam at 212 degrees, so this process is not applied for a prolonged period of time — generally for only up to four seconds. It is then cooled to 39 degrees to slow any possible bacterial growth from occurring in the milk.

If you’re wondering how other bacteria may have survived such extreme temperatures, bacteria tend to play a numbers game. A small amount can become overwhelming in number if left unchecked. Additionally, transferring milk to new storage containers can expose the milk to pathogens, but keeping it just cold enough to slow the bacteria without freezing the milk is sufficient for the most part.

Milk and butterfat need to be separated after pasteurization. It is deposited into large stainless steel drums rigged to axles that spin the milk up to 1,500 times per minute. Centrifugal force pulls the cream from the milk to create two components: butterfat and skim milk. 

The butterfat is pasteurized again and then fermented. During the fermentation process, the fat content of the butter can be altered with skim milk, while adding lactic acid bacteria can change the acidity. The butter is then churned to bind the fat and cream and create the form of butter as we know it. In days past, this was painstakingly done by hand using a butter churn; but, today, it has been mechanized using a piece of equipment that is essentially a giant-sized baking mixer.

At this point, the butter is ready to be smeared onto a delicious bagel, so it is poured into large blocks for transport. 

These butter blocks typically weigh at least 40 pounds each and generally aren’t shipped commercially, but instead are stored and then cut down to specified sizes for distribution. The typical butter sticks you see from the grocery store are cut from these larger blocks using a slicing machine, then packaged by another machine that wraps them in paper or foil to reduce the chance of bacterial contamination during the shipping process.

The process of creating butter has been greatly refined since its Neolithic roots, but the processes largely remain the same. Seal milk in a leak-proof container, jostle it around for hours on end and eventually it will clump together into something resembling butter. Heating liquids to kill microorganisms has been a technique known since the 1100s — though the knowledge of bacteria wouldn’t come until much later. In 1864, Louis Pasteur heated wine to kill microbes and hastily age wine, a technique that was later explored for dairy. This technique was later called pasteurization, and is still used today.

The earliest forms of butter are believed to have been milk stored in a sheep’s stomach that had been converted into a bag and jostled by a day of horseback riding. A similar technique is still used in Syria to create a crude butter, though many western societies adopted some form of a mechanized or hand-powered churn.

Butter can be mixed with a number of other flavors. Artisanal butters are frequently crafted in France by chefs who purchase butter from a manufacturer and then re-churn it with a number of different spices and ingredients to create a unique spread.

Stay curious, 7B.