Most beer is made from four basic ingredients — water, malt, hops and yeast. Understanding the role that each of these ingredients plays in the brewing process results in a better understanding of the flavor profiles of our favorite beers.

Malt is the primary building block of all beers, responsible for much of a beer’s flavor, color, mouthfeel and even its foamy head.

But what exactly is malt?

Simply put, it’s grain that has been through the malting process. The most common malted grain in nearly every beer is barley, but beers can also be brewed with malted wheat, rye and oats or combinations of each.

The malting process starts with raw grain wetted with water and allowed to sprout or germinate. The germination process allows for the development of the grain’s starch-carrying endosperm and creates various enzymes that will break down complex sugars into simple sugars for fermentation when the malt is eventually mashed.

To stop the germination, the sprouting grain is placed in a kiln. As the temperature rises in the kiln, the sprouted barley begins to dry and cure, flavors are set, and the malt is preserved. At this point, the malt is suitable for use as a “base malt,” a lightly toasted malted grain that imparts a neutral bread-like flavor and a light yellow color. For pilsners and other light styles, this might be the only malt the brewer will employ.

After kilning, the grain can be subjected to further roasting to create deeper colors, caramelizing the grain’s natural sugars and producing a malt known in the trade as a specialty malt. Specialty malts are added to brewing recipes to change the sweetness, body and color of the beer. The colors of these specialty grains are measured in degrees Lovibond (ºl) ranging from 1.5ºl to 2.5ºl for light malts called lager malt, pale ale malt and wheat malt, to 35ºl to 100ºl for crystal and other sweet caramelly malts, all the way to 300ºl to 500ºl for chocolate, roasted and black patent malts.

The brewer uses these malts the way a painter uses a palette, mixing and matching grains to achieve the desired color. For example, a typical India Pale Ale will use 85-90% pale base malt and 15-10% crystal malt at about 60ºl. The resultant beer will have a lovely reddish copper color. Whereas a stout might have 88% pale base malt, 10% roasted barley at 500ºl, 1% chocolate malt at 400ºl and 1% black malt at 600ºl, creating a nearly opaque black.

The base malt and specialty malts used in the brewing process contribute not only color but give beer its various flavor profiles. So too does the mashing of the malt (soaking malt in hot water as part of the brewing process). The mash produces both simple sugars like glucose that are fully fermentable and create the alcohol in finished beer, and unfermentable sugars like dextrine and melanoidins, sugars and complex compounds that remain in the beer after fermentation.

The variety of nutty, roasted, toasted, spicy and burnt bitter flavors we perceive are a result of these unfermented compounds. Like the color of beer, brewers can control these compounds, effecting the taste and mouthfeel of the beer. Here the type of roasted malt plays a key role.

While roasting creates flavor, it can also destroy the starches that create the fermentable sugars. Light malts, those not roasted but just kilned, maintain their ability to produce simple sugars. Crystal, caramel and dark malts, because of charring or caramelization, have less potential for creating fermentable sugars and will instead impart their other flavors. Lightly roasted malts bring flavors of toasted bread, biscuits, graham crackers and nuttiness. Crystal and caramel malts will impart a brown sugar, toffee, caramel, molasses or burnt sugar-like flavors. Darker roasted grains contribute roasted coffee, chocolate, espresso and dark fruit flavors.

A beer brewed with 100% pilsner or base malt will be dry or crisp (little to no residual sweetness) and light bodied (a watery mouthfeel). Think Pilsner Urquell or Kona’s Longboard Lager. Conversely, a beer brewed with only 80% base malt and 20% specialty malts will taste much different. Again, the common stout is a good example; the base malt provides the fermentable sugars while the dark malts leave behind a rich (full-bodied, viscous mouthfeel), sweet (residual unfermented sugar), and complex (roasted, toasty, bitter and burnt) flavors.

I’ve only scratched the surface of the role malt plays in beer. If you’re interested in knowing more you might want to pick up a copy of Ray Daniels “Designing Great Beers,” or John Mallett’s “Malt: A Practical Guide from Field to Brewhouse.” Or even better, head over to Long Beach’s only home brew shop, Stein Fillers, and sign up for one of their home brewing or beer appreciation classes. After all, the best way to get to know beer is to make it yourself.