The Science Behind Cheese with Decimal Place Farm

By Kellie Vinal

You might not expect it, but nestled just southeast of the city limits of Atlanta lies a 40-acre oasis of grazing pastures and scrubby brush that 40 adorable adult dairy goats call home. Those in the know will tell you it’s where to find the best goat cheese in town — Decimal Place Farm. A mere 11-minute drive from the Starlight Drive-In Theatre, Decimal Place thrives as a source of freshly made cheeses, delivering feta, mozzarella, creamy chevre, and cheddar to grocery stores, farmers markets, and well-known restaurants around Atlanta.

Three goats at Decimal Farms

Mary Rigdon has been running the farm since her family took over the land in 1995, and is a tried-and-true expert of her craft. With a degree in animal science and background in research with pigs, sheep, and cattle, she’s incredibly knowledgeable when it comes to animals. And it shows – she’s raised her herd of Saanen dairy goats since they were little, and they are noticeably trusting and calm in her presence.

Two adorable goats

“We’re truly all about keeping the animals happy and healthy,” she says. “I love the animals. The better I treat them, and the better I understand them, the better they give back to me.”

Her almost otherworldly intuition puts her goats at ease, and they find comfort in the routine she’s established for them. “Goats are all about routine,” she says. “So, twice a day, at the same time every day – we milk.”

Mary fell in love with Saanen goats – a breed originating from the Saan valley in Switzerland — for their sweet temperaments and superior milking qualities. Over the years, she’s carefully bred and selected her goats for their impressive milk production, as well as their physical characteristics.

“Each animal is identified as to who their mother is and their father is, and I’ve got milk records on the mothers for the last 20 years,” she explains. “I’ve selected all through those years for straight legs, a level top-line, and good feet — so that they can travel through my pastures and do a good job of grazing, which is what they’re meant to do.”

Most days, you can find the goats happily roaming and grazing around the 40 acres of farmland, rotation of which Mary strategically orchestrates to keep both the land and goats healthy.

Goats running in the pasture

“They graze the woods that are around us,” she says. “We have poison ivy, privet, honeysuckle, and the goats eat that, along with the tree leaves and the acorns that are around, and they turn it into that tasty milk.”

Happy goats in the pasture

When baby goats are born, the mother starts giving milk – called lactation – and generally, each goat gives milk for approximately 300 days. The goats at Decimal Place Farm usually give about a gallon a day, if not two, for those 300 days, and Mary and her crew turn it into cheese.

Mary isn’t shy about diving into the science behind it all, either — from the selective breeding to optimization of milk production, to the science behind different kinds of cheeses. Her enthusiasm is palpable as she explains lactation, sketching a curve on the notepad in the milking room.

Science behind cheese explained by Mary

With a twinkle in her eye, she says, “I eat this [science] stuff up. I love it!”

She explains that, after extensive calculations and cross-referencing of milk records, she’s selected for goats that maintain a long, level lactation curve, rather than a large, brief spike in milk production.

It All Begins With Milk

 Goats feeding

The process of making cheese starts in the milking room. Mary’s milking room facility accommodates up to ten goats at a time, each of which gets personal attention to ensure they’re in tip-top shape before beginning. Not only are the goats tested in advance for tuberculosis, brucellosis, and other diseases, but their milk undergoes a quick, simple test that confirms each goat is in good health and thus producing healthy milk each day.

Milking goats process

Once the goats’ udders are dipped with a bleach solution and wiped clean, and their milk is deemed infection-free, the milking process begins – either by hand or by a vacuum-driven machine that mimics the action of a squeezing hand, gently pumping the milk to a receiver. When the receiver fills up with milk, the milk completes an electrical circuit, activating a pump that transfers the milk up and through the wall to a bulk tank.

Mary milking a goat

The milk stays chilled in the bulk tank until Mary’s ready to make the cheese, which is typically the same day the goats are milked. Each day is different, with local chefs and restaurants requesting a variety of cheeses in different quantities. Mary makes sure she’s ready for anything.

“If one chef for one restaurant wants a cheddar and a chevre, and another restaurant wants a feta, then I can make to the orders that I have that day,” Mary explains, “and that way it keeps the cheese fresh for everyone.”

Pasteurizing process

Each batch of milk is first pasteurized – heated above 146 degrees Fahrenheit for 30 minutes – in order to kill any harmful bacteria, then cooled back down. From there, small batches of milk are processed at a time, undergoing slightly different processes to achieve the desired consistency and taste.

The Transformation From Milk to Cheese

In each case, the basic concept is this: milk exists as an emulsion, meaning that microscopic clumps of milkfat proteins are suspended in a mostly watery environment. At the heart of cheese-making is simply removing the water from milk, concentrating the proteins and fats that are already there into solid curds.

Curds

Mary measuring liquidsTo begin the process, Mary adds a starter culture of mesophilic (or medium heat-loving) bacteria, which helps “ripen” the milk, converting milk sugar to lactic acid. This helpful bacteria culture helps the good bacteria in the milk flourish and ultimately makes the chemical conditions just right to develop the desired flavor and texture of the cheese.

Mary explains that milk contains two types of proteins: casein and whey. Casein proteins have little tails that form a protective surface, preventing the molecules from clumping together. During the process of cheese-making, Mary adds an enzyme called rennet, which slices those little tails off the casein proteins. As a result, the casein proteins begin to lump together – called clotting or coagulation, which sets off a domino-like effect until nearly all of the molecules have clumped together. The milk is converted to a solid – called a curd – and the remaining liquid portion (called whey) is separated.

Mary pouring liquid (whey)

You can make any kind of cheese with the goat milk, Mary explains: but it’s the temperature, the time, and the amount of good bacteria and rennet you add to the milk that makes the difference. For instance, to make Decimal Place Farm’s signature creamy chevre, Mary adds her culture of good bacteria to a pot of milk with just 5 drops of rennet – a little bit goes a long way with that stuff. Compared to other cheeses, creamy chevre requires more culture, less rennet, a lower temperature, and a much longer incubation time.

Mary stirring liquid

She explains that she makes feta cheese using a larger amount of rennet, a much shorter incubation time, and a higher temperature, so the bacteria grow more quickly. Over the years, she’s developed a precise protocol for each type of cheese, giving each type a signature flavor that keeps folks coming back for more.

“Now there’s the art, and there’s the science,” she says with a smile.

Separating into curds

Mechanically pressing the cheese to remove excess moistureOnce separated into curds, each type of cheese undergoes a slightly different process to achieve the proper amount of moisture. Most undergo a combination of pressing, scooping, straining, slicing, and salting, the protocol varying a bit for each. Creamy chevre has the highest moisture content of all the cheeses, while cheddar – which requires a few extra steps – has a much lower moisture content, and can keep much longer as a result.

“Making cheddar is a long, involved process,” Mary explains, as she twists the handle of a cheddar press, mechanically pressing the cheese to remove excess moisture.

Cheddar cheese undergoes several rounds of moisture removal before it’s sealed in wax, then aged.

Cheese, Love, and Science

Packaged Decimal Place Farm artisanal goat cheese

When she’s not tending to goats or making tasty cheeses, Mary shares her love of science through her passion for teaching. She regularly leads tours and classes on the farm to curious folks of all ages, guiding groups through pastures and leading cheese-making demonstrations.

Mary slicing cheese

Her enthusiasm is infectious as she describes why some cheeses are yellow, while others are white: cows transfer carotenoids (a natural pigment found in grass) from their diet to the milk, where they bind to the fat and end up in the curds. Goats, however, (along with sheep) do not pass carotenoids to their milk, so their milk is white.

Cheese packed by Decimal Place Farm in front of barns

Her extensive knowledge comes in handy, especially when she encounters folks with allergies or intolerances to cow’s milk.

“The reason is,” she explains, “goat milk [has] shorter chain fatty acids. A cow milk fat molecule would be the whole alphabet, while a goat milk molecule would be ABCD — a shorter chain.” She continues, “The reason why so many people have tolerated goat milk rather than cow milk, [is that] their stomach acids don’t have to work so hard to break the bonds.”

Happy, smiling goat from Decimal Place Farm

Whether you’re allergic to cow’s milk or not, the cheese at Decimal Place Farm is absolutely worth a try. If you’d like to check out some of Mary’s cheese for yourself, you can find her at the Freedom Farmers Market at the Carter Center each Saturday. You can also find her cheeses at the East Atlanta Village Farmers Market on Thursdays, and at Rainbow Natural Foods in Decatur. For more information about Decimal Place Farm and where to find their cheeses, you can find them on Facebook, Instagram, or visit Decimal Place Farm’s website.

#ATLSciChat with @EmoryHealthcare

In case you missed our Twitter Chat with Emory Healthcare physicians, Dr. Scott Boden and Dr. Amadeus Mason, check out the conversation on the science behind sports medicine here.

 

Tiny ALEX Begins Her Journey to #ATLSciFest 2018 with #TinyDoorsATL

Tiny ALEX (Atlanta’s Lead EXplorer) is ready for #ATLSciFest 2018 and has started to explore the city by visiting one of Atlanta’s most prized public art exhibits – Tiny Doors ATL. Founded in 2014, Karen Anderson and Sarah Meng created this Atlanta-based art project consisting of evolving interactive installation pieces that bring wonder to tiny spaces. Principal Artist and Director Karen Anderson maintains the doors throughout the year and now focuses much of her time on creating tiny art for small businesses and companies. We can thank Karen for our wonderful Tiny ALEX!

ALEX and the Atlanta Science Festival love collaborating with local organizations that offer Atlantans accessible STEAM (Science, Technology, Engineering, Art, and Mathematics) experiences. We’re very thankful to Tiny Doors ATL for doing just that!

If you’re looking for even more Atlanta STEAM experiences, this year’s Atlanta Science Festival March 9 through the 24 has you covered. The Festival launches on Friday, March 9 with Rise Up, Robots! at the Ferst Center of The Arts and ends with our free Exploration Expo at Piedmont Park on March 24. Plus over 100 events that take place in-between. Plan your festival experience today! And who knows, you just might meet a life-size ALEX along the way.

Tiny Doors ATLTiny Doors ATL installs 6-inch tall doors in strategic places throughout the city. You could walk past these tiny installations for months and never see them. Next time you’re taking a stroll, be sure to keep an eye out for Tiny Doors ATL!

ALEX (Atlanta’s Lead EXplorer) takes form as both a tiny and live-size mascot for The Atlanta Science Festival. You can get your picture taken with her this year at our range of events spanning between March 9-24.

This colorful door resides near the Old Fourth Ward Skatepark on The Atlanta Beltline and sees a ton of foot, bike, and running traffic each day.

Also located along The Atlanta Beltline, this French style door resides near the Eiffel Tower and awesome vintage store Paris on Ponce.

This tiny door can be found 15 feet from the famous King of Pops walk-up window in Inman Park. It even has its very own tiny sandwich board, sidewalk, and tiny mural painted by artist Chris Veal (the original painter of the larger mural on the same wall).

The Science Behind the Circus with Imperial OPA

How do circus performers balance a ladder on their chin? How does inertia affect aerial shows? The science behind the circus is both intriguing and entertaining, so we’ve turned to Imperial Opa member John Indergaard to help us learn a bit more.​

Juggling

Imperial Opa member John Indergaard shows off his juggling skills in their practice facility!

John, a self-described “general goofy person,” began juggling at seven-years-old in P.E. class and turned the skill into one of his favorite hobbies after his mom bought him juggling clubs for his birthday.
John’s introduction to the circus actually happened thanks to the Atlanta Science Festival. John was studying physics with a research focus on molecular beams at Georgia Tech. While hanging out in the demo room of the Howey Physics building one day, John and a friend gave a tour to a professor who wanted to create a “science of the circus” event for the upcoming Atlanta Science Festival. Naturally, John’s ears perked at the chance to incorporate his favorite hobby and his passion for math and science. Since then, John joined the circus and has become the science expert at Imperial Opa, leading our annual Science of the Circus event each year at the Festival. We hung out one night at circus practice with John to learn more about how he intertwines his two passions at one of Atlanta’s best circus acts in town.

What areas of science are involved in circus performance?

Every circus act can be viewed through the eyes of a scientist. Scientific thought can be used to analyze anything in nature, so I would say that I dissect circus feats through scientific scrutiny more than develop acts based off of scientific principles.

Acrobats

Partner acrobats take hours of practice and teamwork! The scientific trick to these poses comes in analyzing the center of mass, since there can be several acrobats at a time leaning away from each other.

Tell us more about how you use science to perfect your craft.

The great thing about using the circus as an avenue of science outreach is the ubiquity of circus arts in the world and the large degree of separation between circus and science. When people think of circus they probably don’t think of science at all, and vice versa. When an audience, particularly younger students, are presented with an amazing circus act that is given a detailed scientific description it brings up a conflict in their minds: How is this person making the circus about science? What does science have to do with anything here? I try to use these moments to help people realize that science was not created for the classroom or made to be a boring homework assignment, but rather science has been cultivated for thousands of years to give us the most useful and detailed methods to learn something from the world around us – whether that be atomic physics, chemical reactions, or an acrobat on the trapeze! Science can be everywhere around us!

Juggling, balancing partners

This act uses balancing, juggling, and partner acrobats to wow their audience!

What are the main acts of your circus? Could you walk us through the science of each of them?

Sure thing! I’ve broken down the science behind aerial, partner acrobats, tumbling, balancing/juggling, and our fire show below.

Aerial

Aerial

Aerial

Aerial acts can be performed on silks, lyra, rope, trapeze, and other apparatus. When we scientifically analyze these acts we focus on the rotational motion of the aerialist. Specifically, we like to discuss spinning and how the positioning of our arms affects our rotation. Arm position changes your body’s tendency to resist acceleration as it rotates around an axis – extended arms slow the rotation, while tucked arms speed you up. This helps maintain a law of nature – conservation of angular momentum – which depends on rotation speed and shape of the rotating object. If shape changes, then the speed must compensate to conserve angular momentum by changing as well. Aerialists use this principle of physics to seamlessly transition from rapid rotations to slow elegant motions.

Partner Acrobats

Partner Acrobats

Partner Acrobats

Partner acrobatics often demonstrate amazing feats of strength and flexibility, stacking and tangling many people together. We like to demonstrate positions that look odd due to acrobats leaning or hanging from one another. The scientific trick to these poses comes in analyzing the center of mass, since there can be several acrobats leaning away from each other whom look like they should be falling over. However, the center of mass always remains above the stable point (like feet on the ground) even though there is no physical mass at that position! In these cases, a basic understanding of physics can change the way that acts are viewed.

Tumbling

Tumbling

Tumbling

Watching our tumblers jump and flip over each other and audience members always puts a smile on people’s faces! The physical concept demonstrated here is the conversion of linear momentum into angular momentum, like when an acrobat is running in a straight line and all of a sudden tucks into a rapidly rotating position as they make a flip. Since momentum is always conserved, acrobats take their linear momentum (running in an extended body position) and rapidly convert it into angular momentum (flipping with arms and legs tucked). That is why you see these acrobats running so quickly before performing their feats – with all that momentum built up all they have to do is change their body position ever-so-carefully to generate the rotation necessary to perform their amazing flips and twists.

Balancing/Juggling

Balancing and Juggling

Balancing and Juggling

The language of juggling is truly the language of mathematics. All juggling tricks can be described using numbers that represent the number of beats the objects spend in the air, and where the object begins and ends its pattern. Ignoring gritty details, generally speaking odd numbers describe throws that are thrown and caught by different hands while even numbers describe throws to the same hand, with larger numbers of objects requiring higher throws (see siteswap.org for more on this). Perhaps not surprisingly, if you ask a juggler, it is very common for them to have some background or interest in science and mathematics.
Balancing is fascinating from a physical point of view. This boils down to the center of mass and moment of inertia (that is, the tendency to resist rotation) of various objects that a circus performer may want to balance on their chin, or nose, or forehead. An object with its center of mass higher up will have a larger moment of inertia and therefore will require more time to fall. These objects fall more slowly and thus are easier to balance. For instance, it is always amazing to see a performer balance something large like a ladder on their chin, but since the center of mass of the ladder is so high it is actually relatively simple to balance compared to something less impressive like a fork or spoon!

Fire Shows

Fire show

Fire Show

A scientific view of fires requires chemistry! Choosing a fuel with a low burning temperature to allow the performer the most comfort and a high burning efficiency to reduce smoke is essential for a successful fire performance. There can even be fuel chemical additives to allow fantastic colors in the flames! A performer must also understand the idea of ignition temperature, since a wick doesn’t need to be flaming to reignite when reintroduced to the fuel.

What is your favorite part of the circus? Can you share any science secrets about conducting it?

My favorite part of being in the circus is getting such undivided attention from kids who are amazed at all of the diverse acts! Using this amazement to bring young people into a scientific discussion is a slick little trick I like to use to insert science into their everyday lives, especially when they least expect it.

Pyramid

Stay tuned for more information on Imperial Opa’s upcoming #ATLSciFest event in March 2018!

Thank you to Imperial Opa and John Indergaard for walking us through the science behind of the circus. Stay tuned to our website, Facebook, Twitter, and Instagram for more Awesome Science of Everyday Life features and other festival updates!

#ATLSciChat on Video Game Performance with KontrolFreek

If you weren’t able to join in on the chat, don’t sweat it! Explore the links and questions below to learn more about the science of video game performance.​

 

The Science Behind Ice Cream with High Road Ice Cream

How is the matter that makes up traditional ice cream, soft serve, custard, and sherbet different? What elements make ice cream the chilly, luxurious treat we all love? The science behind ice cream is both fascinating and delicious, so we’ve turned to High Road Ice Cream owner Keith Schroeder to help us learn a bit more.

Keith Schroader, High Road's Founder and CEO

Keith Schroeder, High Road’s Founder and CEO, is the first to admit science comes first when making luxury ice cream!

As CEO of High Road Ice Cream, Keith Schroeder will be the first to admit ice cream is science first and everything else comes second. As a chef, Keith didn’t have to worry too much about temperature, engineering, or numbers. But after taking his love of ice cream to the next level, he quickly found adding in machinery on a large scale can become very overwhelming. “I had to become a student of the technical nuance or else… I’d become toast,” Schroeder joked.

ASF Co-Director Meisa Salaita talks with Keith Schroeder

Atlanta Science Festival Co-Director Meisa Salaita talks with Keith Schroeder about the science behind ice cream production.

Schroeder does not actually have a formal science background, but as he discussed the craft of ice cream making, it became clear that he quickly had to become an expert in the study of food science, namely topics like emulsification, freezing point depression, solutions, microbiology, and the science of flavor. Continue reading to learn more about his scientific journey!

High Road Tasting Room

Friends and neighbors can get a glimpse behind the window to see, taste, and purchase products every Saturday from 10AM-2PM!

Walk us through the process of making ice cream from a scientific perspective.

Ice Cream, in a scientific sense, is a foam, solid, and liquid all at once. There are some solids from fats and some from proteins which we have to treat differently, as they respond to agitation differently. To create our base mix, from a scientific perspective, we usually need to think about fats, non-fat solids, water, sugars, and emulsifiers for stabilizing. In a classic sense, that translates to dairy milk, cream, milk solids, sugars, and egg yolks. Then when you want to add flavoring, it throws the base mix out of balance, so you always need to adjust your base mix for whatever you are adding.
Simply stated, the differences in the components of different styles of ice cream are:

  • Soft Serve is lower in fat and higher in solids
  • Custard-based ice creams are richer with the addition of egg yolks
  • Philly style ice cream tends to be high butterfat, no yolks.
  • Gelato is a largely generic and unregulated term that allows US manufacturers to not meet the butterfat requirements for ice cream and is ultimately a cheaper product in the US. Where it is high quality, it’s a stylistic shift that raises sugars and lowers fats – yielding a brighter tasting end product.

What part of ice cream making is the most difficult? Can science help with that?

Automating production is the most challenging, as you’re trying to push very stiff ice cream through stainless pipes while folding caramels and chocolates and other inclusions into the automated stream of ice cream. When you grow your business and start to use machinery that has a very specific functional purpose, you can no longer use your hands in the same way and need to be much more familiar with what is going into the machines – thinking of composition, thermodynamics, phase states, fat agglomeration issues, and so forth. Engineers are priceless in the ice cream industry. For example, the length of a pipe can be very important in the texture of the final outcome. When you are a chef, you don’t think that way. No one ever tells you that if a knife were half an inch longer, the food would taste better!

High Road’s Chief Manufacturing Officer Steven Roddy

High Road’s Chief Manufacturing Officer Steven Roddy shows us the pasteurizing room where their unique process kills bacteria while maintaining a delicious fat content in their base mixture. One of the biggest investments in the company is taking care of food safety. The High Road team is constantly checking to be sure the facility is clear of harmful pathogens like Listeria and coliform bacteria (like E. coli).

300 lbs and 500 lbs heating tanks

These 300 lbs and 500 lbs tanks heat the mixture to 160F for 30 minutes. Afterwards, the mixture is then homogenized by equipment from the 1960’s! The pistons in the homogenizer blend the mixture together to achieve the perfect incorporation of fat, water, cream, and sugar.

Which method of ice cream making do you use and why?

We employ all techniques, as we have customers with different needs. We pride ourselves on meeting challenges presented by customers.  For example, for our High Road branded products, we vat pasteurize our milk and cream. This method heats the milk/cream mixture low and slow which denatures the proteins differently than the faster pasteurization process normally employed by ice cream makers and results in what we feel is a better texture final ice cream.

Other than how you pasteurize the milk and cream, what determines texture and consistency?

Mix formulation, proper ice cream making equipment, and temperature – rapid deep freezing, and proper storage during transportation (-20F).

Freezer

Classic and exotic flavors await consumption in -20F!

Tell us more about the role temperature plays in making ice cream. How does temperature affect taste and texture once you’ve made it?

The rate of freezing is very important to making ice cream, thinking of how aggressive the method you are using is in removing heat from the product. If you freeze too quickly, you don’t have the opportunity to churn and get the texture you are looking for. Freon in the machines like we have here is the best. A mixture of ice and salt would be the second best choice. By mixing the right ratio of salt and ice together, you can make a solution that is cold enough to freeze the ice cream at the proper rate.
After the ice cream is made, the temperature continues to play a huge role. The ice crystals that are created during formulation are finite – not detectable to the tongue. But if the temperature is shocked (going above 10F during transport), the tiny seed crystals in the ice cream grow and ruin the intended texture of the ice cream. This is also what you see if you leave ice cream in your freezer for too long.

Sweet cream mixture

After the sweet cream mixture has aged, it’s time to add the fresh ingredients!

How does the fat in milk affect the process of making ice cream? Can you make ice cream out of milk from any animal?

Fat must be somewhere between 12 and 18 percent to yield a good quality ice cream. Ice cream can be made from milk and cream from any animal, yes. However, cow’s milk is brightest, sweetest, and most abundant. It’s also quite neutral in flavor.

How does air influence in the process of making ice cream and keeping it fresh?

Air is incorporated as a function of churning, and too much air degrades the mouth-feel and quality perception of ice cream. Also, keeping ice cream containers air-tight prevents surface crystallization and keeps the ice cream from taking on off-flavors from the freezer environment.

What is the importance of using regionally-sourced ingredients?

It’s important if the regional item is superior in quality and/or meets our food safety standards. Pecans, peanuts, peaches, and blueberries are exceptional in Georgia.

Fresh ingredients

High Road creates their flavors from scratch by using fresh ingredients which helps their ability to avoid Listeria outbreaks and ensure their products are safe for consumption.

How and at what stage do you incorporate the different flavors? Have you ever had a flavor not taste at all how you were expecting?

Flavoring happens after the mix is refrigerated overnight, and after it’s metered for production. A chef and a quality manager work together to monitor the flavoring of every batch. We must monitor the inputs closely to ensure that the ingredients beyond the ice cream mix ingredients meet our strict quality standards. It’s a craft, requiring attentiveness from the chefs, so yes, there have been times where flavors have missed the mark. We typically catch those off flavors before producing the ice cream, though.

Chefs and quality managers

Chefs and quality managers monitor the input of ingredients closely to ensure that the ingredients beyond the ice cream mix meet their strict quality standards.

Once the ice cream is made, how can packaging make or break the end product?

Packaging must be airtight, allow for airflow in the deep freezers, and stand-up to scooping – either by the consumer or professional. We tend to use industry tested and proven packaging. We’d rather innovate in ice cream than risk a failure with new packaging.

High Road Marietta plant

High Road’s Marietta plant uses ingredients from Mexico, Japan, Thailand, Canada, Tanzania, Ivory Coast, and Madagascar!

What is your favorite flavor of ice cream and can you share any science secrets about making it?

Vanilla. Because vanilla extract is made with alcohol, it’s important to use a double-fold (high concentration) vanilla in ice cream, otherwise, the ice cream can taste boozy, which isn’t welcome in a straight-ahead vanilla ice cream.

High Road Vanilla Ice Cream

Owner Keith Schroeder’s favorite flavor of ice cream is vanilla!

Thank you to High Road Ice Cream and Meisa Salaita for walking us through the science behind ice cream. Stay tuned to our website, Facebook, Twitter, and Instagram for more Awesome Science of Everyday Life features and other festival updates!

Science Chat on Climate Change with Dr. Marshall Shepherd

If you have been following the news lately, it seems like climate change is a hot topic. We wanted to know more about what scientists are saying about the earth’s evolving climate, so we went straight to a leading expert in the field, Dr. Marshall Shepherd, at our Twitter chat last month.

Dr. Shepherd is the Director of University of Georgia’s Atmospheric Sciences Program and currently hosts the only nationally-televised Sunday Talk Show focused on science, The Weather Channel’s Weather Geeks. He is also a former NASA Scientist and was a 2004 PECASE award recipient at the White House. Explore the links and questions below to learn more about climate change.

Dr. Shepherd is the Director of University of Georgia’s Atmospheric Sciences Program and currently hosts the only nationally-televised Sunday Talk Show focused on science, The Weather Channel’s Weather Geeks. He is also a former NASA Scientist and was a 2004 PECASE award recipient at the White House. Explore the links and questions below to learn more about climate change.

The Science Behind Neon Lights with The Neon Company and Georgia Tech

You can’t wander far in Atlanta without seeing the bright, colorful work of The Neon Company. From The Vortex’s iconic skull logo, to the Majestic Diner’s massive outdoor signage, to the hundreds of custom pieces for TV shows and movie sets around the city, the team at The Neon Company specializes in creating neon signs that satisfy the visions of their customers. What most people don’t realize is that each piece created is a result of rare artistic craftsmanship and calculated science.

Glowing neon creations

The Neon Company studio is filled with hundreds of beautiful, glowing neon creations.


Opened in 1984, The Neon Company has perfected the art of creating neon signage and art for the bustling city of Atlanta. Gregg Brenner, the founder, president, and CEO (Chief Electron Officer), started the business with a background in science. With an undergraduate degree in biochemistry, Gregg taught high school science in DeKalb County for five years. During his time teaching, playing with neon became a hobby of Gregg’s and grew to become something much more after he received his Master of Science degree from Georgia State University.
We wanted to hear more about the science behind Gregg’s colorful light displays, so we popped into The Neon Company studio along with another local expert on the science of color and light. Eric Shen, a chemist from Georgia Tech, works in the field of organic electronics. His research on electrochromic materials – materials that change colors when zapped with an electric current – provides him with a unique perspective on how color and light can be manipulated. Eric helped give us some insight into what’s going on at the atomic level with the fascinating light displays that The Neon Company produces, along with how it could connect to his own research.
Eric and Gregg talking

Eric and Gregg discuss the many connections between their two fields of work. In the end, they both deal with light, energy, and electrons!


The neon process can be broken into two parts: the art and the science. Creative design and glass bending involve a lot of artistry. Those steps are immediately followed by the introduction of science and technology when assembling and installing the signs.

Creative Design

The Neon Company receives many neon requests ranging in difficulty.
“We get everything from folks who are just creating their business and don’t know what they want, to well-established companies like Coca-Cola who need a custom job,” said Gregg.
Once the team has an idea of what the job entails, the process starts off at a Windows 98 computer. Yes, you read that right … A graphic for the neon sign is made on a Windows 98 “art” program, which Gregg explains is “so old that no one writes viruses for it.” The computer sends the graphic to a plotting machine that uses a Sharpie to draw out the design on a piece of elongated paper. This outline is used as a stencil for the neon glass benders to work against.

Windows 98 for stencils

Though some might look at these machines as part of the stone age, Windows 98 provides a dependable server for the programs and equipment needed to produce accurate stencils.

Glass Bending

Once the patterns are made, the work gets handed off to Blaze Pearson and Sue Erck, the company’s neon glass benders. Blaze has been bending glass for about 15 years while Sue and Gregg have been bending for 30 years.
“This is the highest level of skill in the shop. It really takes a lot of practice,” Gregg explained.

Hand drawn stencil

Blaze uses a hand drawn stencil to create a star out of coated glass.


The printed outline is placed under a brass screen top so that the glass benders can lay hot glass on top of the paper as they work. Using a variety of flames and torches, the glass bender heats up areas of the glass tube that needs to be bent in order to make the correct shape, but as the glass bends, the bent area will start to flatten, similar to how a garden hose would. In order to keep the correct diameter, Blaze and Sue use a “blow-hose” to blow air into the tube near those bends.
Blaze and Sue using a blow-hose

Blaze and Sue use a “blow-hose” to maintain the diameter of the tubes when bending.


The glass they work with hardens quickly, which means there is less time to fix mistakes. Gregg explained that abstract neon signs are the easiest while precise lettering and large circular shapes are the trickiest. Since the variety of signs they make are so large, the team at The Neon Company is never bored.
Heating Glass

Sue wears goggles while working, because they help filter out specific wavelengths of light from the flare so she can see which areas of the glass are heating better. You can see the difference in the two images above!


“You really have to think it through but that’s part of what makes the job really fun,” said Blaze. “Every day is different and every piece of glass is different.”
Next, electrodes are added to the ends of each piece, heated, and welded together through a process called the “kissing technique.”
"Kissing Technique"

Deemed the “kissing technique”, electrodes are added to the ends of each piece, heated, and welded together before the final assembly.

Assembly

Once the tubes have been properly shaped, it’s time to introduce the chemistry. Before you can fill the tubes with gases that light up, you have to clear out any air and moisture from inside the tubes with a vacuum pump. After the vacuum does its job, a zap of electricity is added while raising the temperature of the tube in order to sterilize the inside and eliminate any remaining  air.
Once the tube is finished sterilizing, the team has to wait for it to cool down to a temperature low enough to add in the gases, which gives the neon sign its color.

Gregg Brenner showing bombaring process

Gregg walks us through the bombarding process which cleans and prepares the tubes to be filled with gas.


The Neon Company mainly uses two gases – neon and argon. Both of these gases are clear when they are added to the tubes, but when electricity is added, they glow: neon glows red/orange in clear glass, and argon gives off a blue/lavender light in clear glass.
So how do these gases go from clear to colored and why do they light up?
“With neon lights, you are applying a huge voltage, which energizes the electrons of the gas atoms. Eventually, all that energy has to go somewhere, and it gets released as light,” Eric tells us. The unique color associated with each gas is connected to the number and arrangement of electrons in the atoms making up the gas.
Powder coated tubes

Powder coated tubes (shown in image on the left) distribute light more evenly compared to other colored tubes. The difference can be seen in the two tubes shown in the right image.


Now, as we know, neon lights come in a variety of colors, not just red and lavender. Gregg shows us how he can manipulate the color by using either argon or neon, changing the tube color through stained glass or powder coating (which distributes light more evenly) and by adding mercury. A few drops of liquid mercury will vaporize in the tube and create other color options. Once the correct gas has been added, the tube is sealed off and gets set up for installation.

Installation

The pieces are then connected to a transformer to be powered. The transformer generates about 15,000 volts and 60 milliamps, which is what provides that jolt of energy to the electrons in the atoms of the gas in the tube. As Eric told us, the energy goes in as electricity and comes out in the form of light and heat, giving us the neon lights that glow as they should. After being correctly powered, the neon signs are ready to be installed.

Gregg Brenner comparing transformers

Gregg shows us a very old transformer (shown in the right image) compared to the types of transformers used today (shown in the left image).


Each and every neon sign and piece of art that The Neon Company produces is the result of incredible skill, science, and passion. In a world where businesses are trying to cut labor and have everything be run through machines and computers, Gregg, Blaze, and Sue at The Neon Company keep their craftsmanship alive and well.
“The neon industry is shrinking. It’s now more of a small, decorative industry [compared to the lighting industry as a whole],” commented Gregg. Eric, however, had other ideas on how to grow the field. As we were clearing out, the two started talking about how they should experiment with coating Gregg’s neon tubes with Eric’s electrochromic paint-like films to manipulate the color of the lights even more.
Who knows if that will ever come to fruition, but what we know for sure is that the city of Atlanta continues to glow bright with The Neon Company’s handcrafted, neon signage lighting its streets.
Neon Company and Georgia Tech
A big thank you to The Neon Company and Eric Shen from Georgia Tech for walking us through the magical science behind neon lights.
Stay tuned to our website, Facebook, Twitter, and Instagram for more Awesome Science of Everyday Life features and other festival updates!

Introducing Science Chat: Our Inaugural #ATLSciChat with the CDC Flu Season

The Atlanta Science Festival is proud to introduce a new series, the #ATLSciChat. In the coming months, we will be hosting live Twitter chats discussing a multitude of STEM-related topics. It is our hope to engage the public in this endeavor, making science relevant in our everyday lives through social media. Continue reading about our first Twitter chat with the CDC Flu Division.

The Science Behind Beer with Orpheus Brewing & Georgia State University

Have you ever wondered what gives beer its complex, distinct taste? What makes a Budweiser taste different from a locally-brewed IPA? Or a stout taste different from a pale ale? The science behind beer is both fascinating and intricate, so we turned to Orpheus Brewing founder Jason Pellett and Georgia State University microbiologist Dr. Chris Cornelison to break it down for us.

Jason Pellett

Jason Pellett
Jason Pellett is the founder, president, and brewmaster of Orpheus Brewing here in Atlanta. As a brewery, Orpheus has historically focused on sour beers. Their flagship brew, Atalanta, (pictured below) was actually the first packaged sour beer made in Georgia! The art and science of making beer is an important part of the process for Orpheus, so the team undergoes internal training on a regular basis to examine and explore the biochemical processes that happen during the beer making process.
Holding Orpheus beer
Jason took some time to answer a few of our questions about Orpheus Brewing, his journey in beer making, and his take on the science behind beer.

When and how did you first become interested in brewing?

I brewed for the first time in my early twenties when it just went along with making everything else from scratch, but that was short lived. I really became interested in brewing after becoming enamored with sour beers back in 2009. I spent about a year just learning everything I could about how sour beers are made before starting to homebrew again in 2010. Though I didn’t think I’d ever actually be able to open a brewery, I focused my homebrew on sours and saisons and kept my eyes on opening a brewery of my own one day.
Kegs

What scientific element of the beer making process interests you the most?

We’re dealing with live cultures, and everything we do influences their ecosystem, which in turn impacts the beer itself. Many of the flavors created by synergistic reactions within mixed culture fermentations, fermentation processes, and hop compounds are not understood very well. Exploring this area is where most of the art of making beer happens, but it’s also an area ripe for further research.
Pouring beer

What is your favorite beer, and can you tell us the microbiology behind that beer that makes it appealing to you?

The beer I’ve been drinking the most lately is Noise and Flesh, our house barrel-aged beer. The wild culture that we use to sour many of our beers (Atalanta, Wandering Blues, and Serpent Bite, Sykophantes) has a diverse microbe population. The souring utilizes various strains of lactobacillus to make lactic acid, but there’s also a large yeast population. For Noise and Flesh we use the culture to not just sour, but also to ferment the beer. We get the sour taste from the lacto, and great stone fruit esters from the yeast.
Pouring and clinking beer

Dr. Chris Cornelison

Orpheus team
Dr. Chris Cornelison (pictured center in the image above) is an applied microbiologist and adjunct professor at Georgia State University. His area of focus is applied and environmental microbiology, which means he studies microbes in their natural environment (presence, distribution, and function) as well as how to use specific microbes or microbial processes for a specific purpose (making beer, treating waste water, and increasing plant growth/productivity). In general, microbiology involves the study of microorganisms including bacteria, archaea, algae and fungi.
We asked Dr. Cornelison to answer a few questions about his specialty and the many scientific processes and steps that are involved in making beer.

What fascinates you most about microbiology?

Microorganisms are the reason all other “higher “organisms exist. They created and sustain our atmosphere, cycle our nutrients, allow us to digest food, clean up our waste, and make many of our medicines. They can live on light and inorganic molecules, as well as at the hottest and coldest places on the planet- even in radioactive wastes. By cell number, a human being is more bacteria than human. The more I learn about the significance and versatility of microorganisms, the more interesting they become.
Creating beer

Describe the microbiological process that is involved in the creation of beer.

The basic material of beer is simply yeast food. Water and grain are boiled so that the naturally occurring enzymes in the grain will convert complex sugar polymers into small fermentable sugars. This solution (wort) is cooled and inoculated with yeast (naturally or intentionally). The yeast consumes the sugar and converts it to ethanol and carbon dioxide, as well as generates additional low concentration byproducts that contribute to the overall flavor of the beer. At some point, all the sugar will be consumed or the yeast will produce more ethanol than they can tolerate and the process will stop. An additional role of microbes in beer is as spoilage organisms. These are typically acid producing bacteria or wild yeast that produces byproducts not intended in the beer and therefore considered off-flavors.
Barrel of beer

What microbiological factors affect the various flavor elements of beer?

The yeast strain selected or the natural consortia of microbes associated with the grains and water if the brewer is choosing to use a natural fermentation impacts the flavor of beer. Also, the composition of the wort and the temperature of the fermentation will influence metabolic activity of the yeast and therefore the diversity and concentration of byproducts they produce.
Beer creation process

Once the beer is made, how does microbiology come into play in terms of the packaging and distribution of beer?

The brewer may choose to use bottle conditioning, where yeast carbonates the bottled beer. A small amount of sugar and yeast are added to the beer when bottled. The yeast rapidly consumes the sugar and makes carbon dioxide in the bottle. The carbon dioxide is forced into the solution, carbonating the beer. The yeast dies when the sugar is fully consumed and settles to the bottom. Additionally, this is a typical route of introduction of spoilage organisms, therefore strict sanitation practices are typically maintained on the filling lines.
Beer storage and packaging

What is the coolest or weirdest fact about the science behind beer you’ve ever heard?

Lager yeast doesn’t appear to exist naturally outside of the brewing environment. It is a hybrid yeast which wasn’t identified in nature until 2011. Some lucky Germans just happened to have this rare wild yeast show up in their brewery and hybridize (a very rare event) with ale yeast to create the lager yeast that dominates Macro-brewing globally, a multi-billion dollar industry.
Beer creation machinery

What is your favorite beer, and can you tell us the microbiology behind that beer that makes it appealing to you?

It depends. I drink a lot of different stuff and always enjoy trying something new. Right now, I have been drinking traditional Belgian beers, Leffe, Hoegaarden, etc. But I also have some local favorites including Orpheus Atalanta and Eventide’s Kolsch. As the weather cools, I will incorporate some stouts and brown ales into the mix. The lineup at Orpheus has me excited from a microbiological standpoint. They are doing some pretty creative stuff. Their use of the bacterial mother culture for souring as well as various barrel-aging processes creates some very unique products.
Beer planning
A big thank you to Georgia State and Orpheus Brewing for walking us through the science behind beer. Stay tuned to our website, Facebook, Twitter, and Instagram for more Awesome Science of Everyday Life features and other festival updates!

The Awesome Science of Everyday Life

Every other month we will be collaborating with different Atlanta-area organizations and scientists to explore the sceince behind everyday life. Be sure to check back for the latest posts and behind the scenes looks, and stay tuned to our sociel media channels to get a sneak peek at upcoming collaborations!