What Are The 4 Main Ingredients In Beer?

Despite all the variety in beers out in the market now, it’s often surprising to people to learn that at its core, almost every single beer shares four main ingredients.

The varieties of beer stem from the different types of these four main ingredients used, the proportions put in each brew, and the different brewing methodologies used.

Curious what these ingredients may be? Read on to learn more.

The four primary ingredients in beerThe foundation of every beer is made of these four essential ingredients:

  • Water (H2O accounts for most of the volume in beer)
  • Barley (this is the typical grain used for brewing beer)
  • Hops (this influences the flavor and aroma of the beer)
  • Yeast (fundamental in the fermentation process, its core purpose in beer is to make alcohol)

We’ll walk you through the importance of each of these in further detail now.

1. Water

Why is water so important in beermaking?

water from the faucet

Water actually makes up the most volume in a beer. Water generally accounts for about 90% of the beer, making it the main ingredient (in terms of volume) and thus – though it’s technically “tasteless” to most people – its influence on the flavor of the beer is enormous.

There are many issues that come into play with water…

  • Is it hard or soft?
  • How are the pH levels?
  • Is it heavily chlorinated?
  • What’s the mineral content like?

The role of water is central to ensuring consistency across batches and (in the case of larger companies with multiple breweries) across geographies. For instance, this is why you hear that sometimes the same brand of beer tastes differently in different countries. It’s the water.

Despite the percentage of water in beer, the selection and methodical use of the next 3 ingredients in the brewing process are where “the rubber meets the road” in beermaking.

2. Barley

holding grains of barleyWith brewing beer, just like when making any alcoholic drink, you’ll need a source of sugar.

Harvested barley needs to go through the malting process to prepare the starch inside for fermentation. When the barley is soaked in water for a few days, these starch-laden carbs are converted into simple sugars through germination. When we look at yeast a little later on, you’ll see the importance of this process. [1]

Germination is arrested when heat is applied. This is called “roasting the barley.” The length of the roast affects the color and flavor of the beer.

“Barley grains possess impressive features that make them ideal for creating the malt required by the brewing industry.”
– Matthew Tucker, Associate Professor

Curious about how all this works? See our article about how to malt barley!

3. Hops

Hops are little green flowers that grow on a “bine.” This is similar to a vine but without tendrils. These flowers are shaped like a cone. These cones become filled with a bitter resin that acts to balance out the extreme sweetness of malt.

How Are Hops Used In Beer?

hops ready for harvestIf you’ve wondered what hops do for beer, wonder no more! Hops are essentially the “balancing agent.” The stage at which hops are added directly controls the flavor. Hops thrown in early leads to a more bitter beer while you can enhance both flavor and aroma by adding it late.


If you’ve ever asked yourself what makes beer bitter, it’s the hops.

If you’ve ever wondered about IPA beer ingredients, it’s the prevalence of hops that gives this style its distinctive taste. (The British added extra hops to their beer when shipping it to India – read about the history of the IPA here).

When it comes to types of beer hops, there are 170 varietals (!). The more hops a beer has, the higher its International Bitterness Units (IBUs). Though “bitter” sounds like a bad characteristic to have in a beer, it’s definitely not always the case – following the rise to prominence of IPAs in the past 15-20 years, brewers are increasingly adding hops to add the much desired “hoppiness” (and accompanying bitterness) to their beer.

Seeking a hoppy and bitter flavor, many brewers now use hops as far more than just a stabilizer in the brewing process. The resulting hoppy taste becomes the defining characteristic of these beers.

Do All Beer Have Hops?

No. There are lots of beers out there without hops. However, brewing without hops is not very common. If you leave this marvelous flower out of the brewing process, you may end up with an oversweet and flat-tasting beer, if you’re not very careful!

4. Yeast

Of the main ingredients in beer, yeast may appear to be the least interesting (and it’s certainly the one’s whose properties are least visible to the naked eye). Nonetheless, but it plays a fundamental role in the brewing process.

Does Beer Have Yeast In It?

scoop of yeastAs many old brewers say, they do not make beer. Yeast makes beer.

Yeast is a fungus, a single-cell microorganism. The yeast eats the simple sugars created in the malting process converting it into carbon dioxide and alcohol.

The brewer needs to give this fungus a helping hand by making sure there’s enough food for it to feast on as well as keeping the temperature and light levels just right.

After a week or so of eating and reproducing, the environment becomes toxic for the fungus, at which point the brewer can draw some off, ready for the next batch.

While yeast can have an effect on the final flavor, its core purpose in beer is to make the alcohol itself.

Types of Yeast

  • Ale Yeast: Ale yeasts collect on the top during fermentation and are fermented at 60 to 75 degrees Fahrenheit
  • Lager Yeast: Bottom-fermenting lager yeast undergoes fermentation at cooler temperatures from 40 to 50 degrees Fahrenheit

Ales have a more complex arrangement and are much heavier-bodied.

Lagers are lighter and very crisp.

This differentiation between Ale Yeast and Lager Yeast is actually a core defining characteristic of beer. Read more about what differentiates Ales vs. Lagers here.

What Makes a Good Beer?

beer with barley and hopsWhat makes a good beer is almost entirely subjective – and you could spend a lifetime searching for your perfect brew.

While the 4 main ingredients in beer are common across almost all beer varieties, the way in which they interact brings about wildly differing flavors. On top of that, given the countless other ingredients brewers can add to their product, there really is an ideal beer for every palate out there, no matter how unique your tastes are!

Now that you’ve got a solid idea about beer content, you can approach the brewing process with a little more confidence. If you’re curious about how to make beer yourself, check out our introduction to How to Brew Beer or explore our site for some great ways to get started. With just the basic beer ingredients above, you can start experimenting until your brew is just the way you like it!

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