What Is Malt?

By David Nilsen

Hops get a lot of buzz from beer lovers because of their expressive, fruity aromas and flavors, but malt is really the foundational ingredient of beer. You can technically brew beer without hops (though all commercial examples contain them), but you can’t brew it without malted grain, and the different malt varieties offer a dazzling rainbow of potential colors, aromas, flavors, and textures for building a new beer.

While the comparison isn’t perfect, malt is for beer sort of what cacao is for chocolate; without it, it wouldn’t be beer. While other ingredients play major roles, beer is at its base just fermented malted grain. 

What is malt?

Malt is a grain (usually barley, but wheat, rye, and other grains get used as well) that has been prepared for the brewing process. In order to explain what that means, we need to take a look at how grains grow new plants in the ground. 

When a grain seed falls into the soil in a field and reaches a particular moisture level and temperature, it wakes up and prepares to grow a new plant. That involves enzymes in the grain converting the grain’s starch reserves into sugars that will fuel the tiny plant’s growth until it breaks through the surface of the soil and begins generating energy through photosynthesis. 

When a maltster makes malt, she simulates those temperature and moisture conditions and tricks the grain into believing it will grow new plants. Those enzymes that get developed are important to the brewing process, because brewing yeast can only ferment simple sugars and cannot ferment complex starches. We need the enzymes to do their work so we can ferment beer from the grain.

Once the enzymes are fully awakened and have begun to “modify” the grain, the maltster halts the process by heating and drying the malt (the method of drying will determine what type is made—more on that in a moment). This essentially locks the enzymes in place so they’re ready for the brewing process, but doesn’t allow them to finish converting those starches into simple sugars. That will happen during a step of the brewing process called the mash.

How does malt get used?

The first step in the brewing process involves milling (grinding) the malt into a course meal and mixing it with hot water (around 150°F). This process is called the mash, and over the course of about an hour, the enzymes awakened during the malting process finish converting the malt’s starches into simple, fermentable sugars. 

After that process is complete, the unfermented beer (called “wort”) gets drained off the malt. In addition to the fermentable sugars that the yeast will ferment, this process also extracts color, flavor, and aroma from the malt, as well as proteins and dextrins (long-chain sugars) that will give the beer body, texture, and an attractive collar of foam. 

Simply put, malt influences every single sensory aspect of a beer: appearance, texture, aroma, and taste.

The malt or “spent grain” left over is then often given to farmers as livestock feed, and it can even be baked with!

What are the types of malt?

Malts are roughly divided into two groups: base malts and specialty malts. 

Base malts are dried very gently at lower temperatures, and they retain all of their fermentable sugars and the enzymes to convert them. These malts are pale in color and make up the foundation of all beer styles—even dark ones—making up anywhere from 70-100% of the malt bill for a beer. 

Specialty malts are created to impact flavor, aroma, color, and mouthfeel more than to contribute to fermentation, and may have most or all of their enzymes and fermentable sugars destroyed during the drying process. Because of that, they can never make up the majority of the malt recipe in a beer.

This includes malts that are roasted much like how cacao or coffee beans get roasted, and often have flavors similar to those beans. These are the dark malts that give Porter and Stout styles their dark color and roasty flavor and aroma. This also includes malts that have their sugars crystalized during a special process, and malts that have been kilned at a higher temperature than base malts to develop a more toasty color and flavor. 

Finally, there are malts that are dried with smoke to pick up smoky flavors and aromas. You can hear all about these smoked malts in Episode 05.

Every beer you’ve ever tasted, from the palest light lager to the darkest, heaviest Imperial Stout, was brewed with malt. It’s the foundation of all beer, even though it doesn’t get as much attention as hops. 

If you want to hear a much deeper, geekier dive into malt and how it’s made and used, listen to Episode 09 below, which includes interviews with Riverbend Malt, Carillon Brewing, and French Broad Chocolates (whose best-selling chocolate bar is made with brewing malt).