What Is Beer Made Of? The Most Common Ingredients and Brewing Techniques

by Caitlin Berard

Back in the day, most bars had between six and eight types of beer on tap. Today, however, bars and breweries have taken things to an entirely new level. Because of the growth of the craft beer industry, it’s not uncommon for bars to install as many as 40 taps, each containing a different type of craft beer.

With the various fermentation methods and flavors, not to mention the history and origin of each brew, the brewing process can appear dizzyingly complex. However, the answer to the question “What is beer made of?” is deceptively simple. All beer, regardless of minor ingredients and creation process, is made of four main ingredients: grain, hops, yeast, and water.

But wait. If it’s that simple, how can there possibly be so many different types of beer? How can four ingredients be used to create hundreds of thousands of distinct recipes? Well, it mostly comes down to the brewing technique and minor ingredients. Many brewers nowadays add flavoring with spices, sweeteners, and fruit extracts, making the ingredient list a bit longer than the classic recipe.

Here’s how it works.

So, What Is Beer Made Of?

Okay, let’s talk about the four main ingredients first. And actually, the water component is pretty straightforward. Beer contains up to 95% water, so the quality of the water used in brewing is of the utmost importance. The mineral content can have a drastic effect on the final result.

Though the mineral content of water can be altered, it’s often left untouched, as the minerals of a specific region are what gives the beverage of that area its distinct flavor.

Now that we know everything there is to know about water in beer, we’re left with three ingredients: grain, hops, and yeast. These ingredients’ effects on the taste of beer are a bit more complicated.


The grains used in brewing can be anything from barley to wheat to rice to oats and beyond. Barley and wheat have to be malted before they can be used to make beer, which causes the grains to release their natural sugars, stimulating fermentation. Different grains will create different flavors and aromas, colors, and fermentable materials.


Hops are the all-important ingredient in beer brewing. They are what creates the aroma and bitterness of beer, as well as the bulk of the flavor. When hops are boiled, the acid they contain bitters the beer, which means the less time hops are boiled, the less bitter the final product will be. Like any plant, there are a wide variety of hops, each with its own unique flavor and aroma.


While beer ferments, the yeast consumes the sugars released by the grains, in turn creating ethyl alcohol and carbon dioxide. The two main types of yeast used in brewing beer are ale yeast and lager yeast; however, there are hundreds of different strains within the main categories. Different strains of yeast yield different styles of beer.

Common Brewing Techniques

Though there are virtually endless types of beer, there are only three main brewing techniques: extract brewing, partial mash, and all-grain brewing. The main difference between these techniques is in the base of the beer.

Malt Extract Brewing

The first, and easiest, type of brewing is called malt extract brewing. This technique uses a simple extract from the grains to form “wort” or the base of the beer. There are two types of malt extract, dry and liquid. Typically, one form is used, although it’s possible to brew a beer using both.

Brewing with a malt extract requires four easy steps. Heat the water, make wort, add the hops, chill the beer. Then drink!

Partial Mash Brewing

Partial mash, or “mini-mash” brewing uses a small amount of malt extract and a larger amount of grain. The addition of grain results in a more complex combination of body, flavor, appearance, and quality. Rather than jumping straight to making wort, the grains must first be steeped to extract the flavor.

After the grains have been steeped for the appropriate amount of time, malt extract can be added. You then have wort, and can add hops and so on.

All-Grain Brewing

Last but not least is all-grain brewing, the most complicated brewing method. Because this technique is so complex, its reserved for professionals and those with a great deal of experience home-brewing. All-grain brewing uses no malt extracts, meaning the grains must be milled before being put in the water to steep.

After that, reaching the correct temperature while maintaining the perfect stirring method are musts. Once the mixture reaches the ideal temperature, it’s time for lautering and sparging. The hot fluid is washed off the grains and the wort process begins. Only then can the wort and hops be added.

The Beer Purity Law, Reinheitsgebot

The classic method of brewing contains no further ingredients, but many modern craft beers contain spices, sweeteners, fruit extracts and peels, and other flavorings to create a unique brew.

Now you have an important question to answer. Will you, or will you not, follow Reinheitsgebot? Otherwise known as the Beer Purity Law, Reinheitsgebot is a decree dating back to 16th century Germany, making it the oldest food safety and consumer protection legislation still on the books. The original text reads, “We wish…forthwith that…in all our towns and markets and in the countryside no other items be used for beer than barley, hops, and water.”

Don’t worry, beer lovers, yeast was added to the list in the late 17th century. You haven’t been breaking Reinheitsgebot all this time. That said, if you make (or drink) any tasty alcoholic beverages containing anything other than the four classic ingredients, you technically can’t call it beer, according to the rule that emphasizes pure ingredients and no unnecessary additives.