Rollins College biology professor Paul Stephenson shares tips on brewing beer based on personal experience and the principles of botany.
The homebrewing of beer and wine keeps gaining popularity, as kits become cheaper and more available.
But the process holds a special fascination for biologists such as Paul Stephenson, who are enthralled with things such as the cellular respiration of yeast. That’s a scientific term for part of the fermentation process spurred on by yeast. Ultimately, that creates alcohol, as well as the carbon dioxide that allows homemade elixirs to bubble with frothy goodness.
“Yeasts are really cool,” Stephenson says. “Many biologists are homebrewers because when you understand cell respiration and the process that creates alcohol, it seems simple.”
However, as the associate professor of biology will attest, it’s far from foolproof. And while Stephenson does not claim to be a master brewer, he does have 30 years of homebrewing experience and even more time spent as a serious student of biology.
On the day we visited Stephenson at his home, he was making a brown ale, one of his favorites due to its slightly sweet flavor.
(Photo by Scott Cook)
How to Brew a Brown Ale
Step 1: Heat toasted barley in one and a half gallons of water, while stirring, until it reaches 160° F. Remove from heat, cover, and allow to sit for one hour. Fun fact: The color of beer comes from how toasted the barley is. The longer you toast it, the darker the brew.
Step 2: Filter out the barley over a large pot, allowing the liquid, or wort, to separate from the grains. Then pour one gallon of hot (170° F) water over the grain to rinse out any extra sugars, a process known as sparging.
Step 3: Return liquid to the brew pot. Stir in liquid malt and the first batch of hops to the brew. Bring to a boil and heat for 30 minutes. Fun fact: Hops come from a vine, and the oil from the vine’s flowers give beer its bitter flavor. While he was in grad school in Massachusetts, Stephenson grew his own hops, which flourish in colder climates.
Step 4: Add Irish Moss, an algae that acts as clarifier by removing proteins and keeping the beer clear. Boil for 30 minutes.
Step 5: Remove the brew pot from heat. Steep a second packet of hops for five minutes.
Step 6: Remove both packets of hops.
Step 7: Fill a primary fermenter, such as a large glass bottle, with three galloons of cold water and add the wort. Allow it to cool to 80° F.
Step 8: Once the wort has cooled, pour the liquid yeast into the fermenter. This is called pitching the yeast.
Step 9: Let beer ferment for 7-10 days. Bottle. Enjoy.
Tips for Beginners
Start small. If you want to try homebrewing without shelling out big bucks, you can spend $50 to $60 for a starter kit that should provide everything you need—ingredients, equipment, bottles, and caps.
Of course, you may not make a gourmet beer that will be the toast of the connoisseurs around the world, but you can run off 2.5 gallons in about two weeks and then reuse most of the equipment.
If that whets your appetite for more advanced brewing, you easily can add to your hobby.
Check online for local homebrewing groups. You can find like-minded people and helpful details, as well as information about local stores that cater to homebrewers. If you want to take it to the next level, you might have to invest a couple hundred dollars in better equipment. That will let you refine your brewing and make at least five gallons at a time.
Check local regulations. Remember it’s illegal to sell alcoholic beverages without a license, but most localities allow homebrewing, though some restrictions may apply.
Use fresh ingredients. The beginners’ homebrewing kits are a little like instant cake mixes with nearly everything you need in a box. Those results might be tasty, but fresh ingredients will make it even better. With a little knowledge or guidance, homebrewers can select hops and grains from specialty stories and online suppliers. Some hobbyists even grow, dry, and toast many of their own ingredients.
Be aware of the temperature. (Florida homebrewers take note.) Our heat and humidity makes it tough to brew lager beers. Those beers (often the clear, gold-colored brews) typically require cooler temperatures of 68 degrees and below during fermentation. Nobody wants to pay the bills that would come from cooling a house down to that temperature when it’s 95 outside. You could buy a special chiller, but Stephenson suggests just focusing on the ales, which ferment nicely at about 72 degrees and produce a malty—sometimes sweet, sometimes smoky—flavor.
Don’t wash your equipment with soap. Use a non-soap sanitizing rinse, such as a little bleach, and hot water. Soap residue will kill or interfere with the yeast. Low-performing yeast means less carbon dioxide production, which means flat beer. Stephenson said he learned this hard way and once wound up with five gallons of fizz-less beer. He had wanted to show off his skills to friends, but he didn’t dare share the lifeless brew. “It was embarrassing. I drank it. But it was embarrassing.”
Don’t be afraid to try new flavors. As a scientist and as a homebrewer, Stephenson approves of experimentation. Just as chefs and artists have to stretch their skills to improve, homebrewers can try different recipes to sample new flavor combinations or create their own style. If you experiment, however, remember you might get a batch that is too bitter or too sweet.
Brewing Meets Biology 101
By the way, Stephenson has found that he can grab the attention of students in his introductory biology classes on seemingly dry topics such as plant glycolysis by reminding them that it’s essentially the same process that has been used to ferment grains and grapes into beers and wines for thousands of years.
In one of his lab sessions, students run analyses on fermenting yeasts to get a feel for scientific research and the intricacies of cellular respiration. They’ve even tried making their own wine, which Stephenson says, is far from drinkable.
Meanwhile, Stephenson finds that it’s fun to continue to challenge himself by drawing on his scientific knowledge to create interesting beers for friends and relatives. The more he learns, the more he realizes he can’t claim to have all the knowledge of a professional brewer.
But one of his former students does. James Bruner ’09 took Stephenson’s Introduction to General Biology course and became intrigued by the science of brewing. After college, Bruner decided to learn more and became a craft brewer. He now is a brewer for the Terrapin Beer Company, a growing company, headquartered in Athens, Georgia.