The Art & Science of Homebrewing

07 December 2017




Homebrewing invokes the spirit of the mischievous brew master to ferment the finest beers in your own home. A good brewer needs to know the proper method of fermentation and the process requires patiences and skill.

But is homebrewing more of science or an art? Different brewers would give you different answers. Most are fascinated by both elements of homebrewing, particularly when it comes to the production of seasonal beers, which call for creativity to perfect the flavour and fermenting time.

The Science Behind Homebrewing

It would take a lifetime to understand the science of homebrewing beer. For many, the passion behind the hobby leads to that level of dedication, but you only need to understand the basics to get started. Science assists you with understanding how just four main ingredients come together to create the tasty alcoholic beverage.

·         Water: The quality of your water will affect the quality of your batch, but not necessarily in a bad way — which is where the need for creativity and experimentation comes in. Is your water soft or hard? Do you purify tap water, and have you researched your city’s mineral content?

·         Malting: The malting process converts the energy from grains into fermentable sugar, eventually producing alcohol. Malting also affects the appearance and taste of the final product, placing it somewhere on the spectrums of light to dark and sweet to toasty.

·         Hops: Hops are what make beer bitter. How “hoppy” is your beer? This question sets IPAs away from other beers as you focus on brewing a particular type of beer. Hops enhance head retention, as they contain isohumulones, a form of alpha acid that acts as their primary bittering agent.

You must learn to calculate International Bittering Units (IBUs), and what you’re doing is calculating how bitter your beer will be — it’s a fancy, scientific way to describe “measuring the isomerised alpha acids” in your beer selection. Pro tip: Don your lab coat and manically laugh when you say this.

Fortunately, there are a plethora of online calculators to do the math for you if you simply want to focus on the art of brewing. Note that IBUs won’t measure hop oils, which produce the aroma of the beer. Fixed oils don’t add much to the aroma, but the volatile oils of the hop plant enhance the aroma, just like in perfume and herbal concoctions.

·         Beer Yeast:  Most people know you need to let activated yeast sit with water before you begin baking bread, but various types of yeast do different things. Beer yeast as a microorganism converts sugar into carbon dioxide and alcohol in to a type of "sugary porriddge" which will become your beer. 

These four ingredients create the chemical equation that produces beer: C6H12O6 (glucose) → 2 C2H5OH (ethanol) + 2 CO2 (carbon dioxide). In terms of chemistry, fermentation occurs as a metabolic process whereby an organism transforms a carbohydrate, such as a sugar or starch, into alcohol. In this case, the yeast converts glucose to make beer. Zymology is the study of fermentation, and while 14th-century alchemists made notes about fermentation, it didn't become a subject of study until the 1600s.
In the 1800s, the first zymologist, Louis Pasteur, discovered fermentation was generated by living cells. He couldn't locate the enzyme which caused it, however. Chemist Eduard Buechner ground up yeast in 1897 and removed a liquid extract, which he found fermented a sugar solution.
What makes a good beer is in the art of the process, but many major molecules add to the mouth-feel and flavor of a quality brew, including carbonation, residuals sulfur compounds, esters produced and the total amount of alcohol in the beer.
The longer a yeast grows, the more esters are produced. For example, isoamyl acetate is an ester that tastes like pears and bananas and is common in wheat style beers, while the flavor of ethyl hexanoate resembles anise or a red apple taste.

The Art Behind Homebrewing

First, you may or may not wish to don a black beret along with your lab coat. Your fashion choices are yours, as are the decisions you will make as a homebrewing artist. Along with the scientific aspect of brewing, there’s the sensory aspect as you create your final product.

You’re creating an experience for the person drinking your beer. Imagine sitting down at the end of a long day or watching a game with friends. What does that feel like? What does the beer taste like?

Different flavours affect the mind and your mood, and of the five senses, smell is the most powerful, as it recalls memory.

As you know, beer comes in many flavours. Chefs and wine enthusiasts use similar words to describe aromas, and what senses they evoke as the food or drink sits on the palate. The vocabulary unique to beer tasting, as well as the art of homebrewing, comes with experience.

Homebrewing is both a science and art, but to become a homebrewing artist, you need to learn the basic scientific understanding to get started. Making your own beer requires that you seek balance in the recipe and process, and scientific measurements while being creative.

Ultimately, you become more inventive as you get used to particular recipes and want to make them your own. You ask questions such as, “How much coriander should I put in this Belgian Wit? What if I do something a little different?” You use your knowledge, senses and imagination in equal parts as you experiment with flavours and ingredients.

Experience, which you’ll only earn through trial and error, will help you learn when you need to move your beer from one fermenter to the next. For example, a days-long lag in waiting for your beer to ferment means a weaker product, and that the beer’s just replicating biomass.

Eventually, you’ll have enough know-how to bottle every drop without letting any beer go to waste. Many small-batch homebrewers use a popular keg called a ball-lock Cornelius keg — or a “corny keg,” for short — which prevents waste, spoilage and is easy to clean. A quality keg prevents contamination and simplifies the process.

Homebrewing makes an excellent hobby for engaging both the scientific and artistic parts of your brain. You will never be bored with it, as there are endless recipes to try and knowledge to earn. Now, get to brewing!


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