Learn About the Science Behind Making Beer

Drinking beer is one of the ways to enjoy a hot weekend afternoon. It is also a popular beverage when watching movies, gathering with friends, or even while eating dinner. But did you know that there’s a lot of science that goes into creating beer? Science is probably the last thing on your mind as you drink a nice, cold beer. But isn’t it good to learn how what you are enjoying was made? 

There is science on the types of beer, the various flavors, and how it is alcoholic. If you are a beer lover and you’re curious about how it is made, you’re in the right place as we are giving you the best information about that. Read on to learn about the science behind making beer.

The Ingredients Needed in Making Beer

inside a beer brewery

When making beer, there are only four ingredients needed, which are water, malted grains, hops, and yeast. All of these are present in any type of beer out there. Hops are used for flavoring. They are also sometimes used in herbal medicine. When you have all of these four ingredients, then you can start making beer. These are all boiled together for specific amounts of time until the final mixture is filtered and directed to fermentation. 

You might wonder, how come there are different kinds of beer when the same ingredients are used in all of them. Well, it’s because the combinations and process make all the difference. 

Water Quality

One of the things that make beer types different from one another is the mineral contents in your source water. Calcium and magnesium, also known as hardness, can affect how the yeast grows and metabolize the sugars in your beer brew. In addition to that, bicarbonate or HCO3- in the water can also affect the pH of the beer during its fermentation stage. 

Brewing Method

If you are aiming to brew a beer that is caramelly or toasty, it is required that you roast the grains more than usual. This is because darker roasted grains result in grains that have more tarnished glucose molecules, which creates a darker kind of beer. 

The Science in Hops

fresh hops for beer brewing

Hops are the main driver behind modern beers. This means that without them, pints of beer would not be that enjoyable. It’s because hops act as a wetting agent that enables bubbles to be trapped in the head of a beer. If there are no hops added to the beer, it would have lesser surface tension, which will result in no head and a bitter taste. 

Hops can also give beer certain flavor notes. However, its main effect is stabilizing the brew to allow our pallet to taste all of the different bitter and sweet flavors of a beer. It means that without hops, we won’t be able to taste the flavors and as well as enjoy beer. 


In addition to hops, another important part of brewing beer is the yeast. In fact, it is the most essential element to making the beer carbonated and alcoholic. Yeasts are little cells that seek out the glucose or sugar molecules in beer that are left by the grains and hops. Through fermentation, the yeast turns glucose into ethanol or alcohol and CO2. 

Here is the specific chemical equation of fermentation:

C6H12O6 → 2 C2H5OH + 2 CO2

This is the universal fermentation equation, but specific products can be affected by the kind of yeast used in brewing. 

Among the different types of yeasts, ale yeasts are top-fermenting. This means they can ferment at higher temperatures. Yeasts can also ultimately produce more esters, which are organic compounds or simply oils and fats. 

Lager yeasts, on the other hand, are bottom-fermenting. This means that they ferment at lower temperatures, and they produce crisper-tasting beers. There are also wild yeasts, which are not used often in the brewing process. However, when they are, they can make a mixture of compounds that are more acidic and a developed taste. Wild yeasts are rarely used as the exact flavor profile is more difficult to control from a brewing standpoint. 

During the fermentation stage, some molecules can have various effects on the final feel and flavor of the beer. Some of the things that contribute to the final flavor profile of the beer are the length of carbon chains in alcohols, the amount of alcohol, residual sulfurs, carbonation levels, and type of esters. 

What are the Factors that Affect the Flavor and Fermentation of Beers?

people holding mugs of beer

Some of the things that can influence the fermentation and flavor of beers are temperature, mineral content, pitch rate of yeast, length of the fermentation process, and aeration. These variables are closely controlled by brewers to achieve the flavors that they like out of a final brew. Esters that were produced during the fermentation stage can also be predicted and controlled to create certain flavors. 

The most common ester in beer is ethyl acetate, and this smells like nail polish remover. However, in order to smell it, a high content is needed to be present in a beer. But this is not usually the case. Another ester is isoamyl acetate, and it smells like bananas. It is found in many wheat beers and Belgian beers. 

Beers that have sweeter notes probably contain ethyl butyrate, as it gives a hint of pineapple or passion fruit to the beer. And lastly, ethyl hexanoate is an ester that gives the beer an apple-like flavor. 

The Steps in Brewing Beer

different types of beer in glasses

Let us take a look at the step-by-step process of brewing beer:

1. Malting

Malting is the very first step in brewing beer. In this step, barley, which is grain-like wheat, is soaked in water to soften. After that, it is spread out to start germinating. During germination, enzymes are released by the plant, and these are called protease and amylase. These enzymes change starchy nutrients into sugars and peptides. The grains are baked at a low temperature to produce malt. 

2. Milling and Mashing

After producing malt, it is then milled or cracked open, and mashed or dissolved, and mixed into water, which creates a sugary fluid called wort. This is then boiled, and then the hops are added for flavor. The hops bond with the peptides and proteins to sterilize the mixture and stabilize its foamy texture. After that, the hops are filtered out, and the mixture is cooled in preparation for the next step. 

Find out more about beer foam in our post about the science of beer foam.

3. Fermentation

Fermentation is the part that gives the beer its bubbles and alcohol content. When yeast is added to the mixture, it will convert the sugars to carbon dioxide and ethanol over several days, which will give the beer additional flavors. Most fermentations are done with one or two main species of yeast, which we’ve mentioned earlier. Each type requires a different fermentation temperature to work properly. 

Regular yeasts ferment well at 65°F to 70°F, but it can be used with fermentation temperatures as high as 85°F to 90°F. These methods are all warm fermentation. Lager yeast, on the other hand, is fermented at a lower temperature, such as 50°F or so. This is referred to as cold fermentation, and lager beers are made using it. 

In addition to yeast, bacteria like Pedi coccus and lactobacillus can also be added to give a tart flavor to the mixture. These microorganisms multiply fast and can introduce new flavors to the process over time. 

4. Conditioning or Aging

After the fermentation stage, the beer will be stored for a certain period, and this is called conditioning or aging. This stage will allow the beer flavors to mix and mellow out. This process can take from about a couple of weeks to several years, depending on the kind of beer being brewed.

There are also some who choose to age beer underwater. Find out more about this in our article about how aging beer underwater transform its flavor and quality.

5. Clarifying and Filtering

There are kinds of beers that are clarified at the end of the brewing process. In this step, a clarifying agent is added to the beer. This can remove proteins and other substances that make the beer appear cloudy. Back then, this step is done with a swim bladder from fish which is called isinglass. However, at the present time, it can be done with certain kinds of seaweed or by using an artificial clarifier called polyclar. 

Filtering is the last step in the beer-making process. The beer is filtered to remove any remaining solids before it is bottled, canned, or kegged for sale and for drinking. 


When you take a look at the ingredients and the processes in brewing beer, it may seem so easy. However, most of the beers we enjoy today take a lot of time and effort to be produced, most especially craft beers or those that are made in a traditional way by small breweries. It is indeed amazing to learn that there is a lot of science behind making beer. We hope that you learned a lot from the information that we shared here. If you are looking into learning more about beer, check out our Guide to Beer, which contains almost all the things that you need to know about it.