Jon Abernathy

Beer School: The four ingredients of beer

Beers these days are being brewed with all sorts of things: fruits, nuts, herbs, spices, vegetables, various sugars, flowers (besides hops), spruce tips, coconut, coffee, chocolate, licorice—the list goes on, and quite frankly, if you can think of it, someone has probably brewed with it. Lately it seems that beers are notable only for the exotic ingredients that go into them, rather than for the four basic ones than almost all beers have in common.

For this article we’re going to brush away all those extras and get back down to the heart of the four basic ingredients that define “beer”: barley, hops, water, and yeast.

Water

The primary component of beer, making up anywhere in the range of 80-99% of its composition, water plays a critical role in the final character of the beer, yet it’s often the least considered ingredient. We just don’t think about it! But water in fact has a number of chemical properties that affect the final character of a beer.

In fact, many of the world’s great beer styles came about due to the chemical makeup of the water in the originating region:

• The alkaline hard water of Dublin, Ireland, led to the development of the Irish dry stout, as the higher acidity of the dark roasted malts in the mash lowered the pH (increased the acidity) of the water to make it suitable to brew with.
• The high concentrations of gypsum in the waters of Burton-on-Trent in England worked in the opposite direction: the pH is already low enough to not have to use the darker malts, and the calcium helps extract bitterness from hops—leading to the development of paler, hoppier beers.
• In Pilsen, in the Czech Republic, the very soft, low-ion water allowed the brewing of extremely pale, extremely clear beers: the Pilsner developed as a result.

Brewers can chemically alter their water when brewing certain styles of beer in order to make the water more ideal for that style: adding gypsum (calcium) when brewing a Dry Stout, for instance, or they may treat the water with various salts to adjust ion levels for a target profile.

An advanced look at water chemistry is beyond the scope of this article; but suffice to say, don’t discount the quality of water used in the brewing of a beer. Here’s an interesting experiment relating to water: see if you can get beers that are brewed to the same recipe but in different locations (for instance, if a contract brewer contracts their beer recipe out to brewers in separate regions), and do a side-by-side tasting. Are the beers different? If so, all else being equal, it’s the water.

(I’ve heard anecdotal evidence to this effect for the beers of Kona Brewing: the beer they brew in Hawaii—where the water is markedly different due to the volcanic nature of the islands—is different from their beers available here in the mainland, since it’s contract-brewed by Widmer. Same recipes, different water.)

Barley

Barley is a cereal grain that serves as a major food source, feed crop for livestock, and of course is the source of fermentables for beer.

Of brewing barley, there are two types used: two-row and six-row, so called because of the number of seeds growing on the stalk (or more specifically, the pattern of seed growth). Two-row barley has a higher starch content and is often regarded as superior to six-row; many of the traditional European styles of beer are brewed with two-row barley, while historically American brewers cultivated and brewed with six-row barley (whose higher levels of diastatic enzymes aided in the mash conversion of adjunct grains).

You can’t just add barley grain into a pot of water and expect to get beer: the raw kernels are full of insoluble starches that need to be converted to soluble starches and sugars before they can be used, in a process known as malting. This is basically accomplished by getting the grains to germinate (sprout), and then halting the germination process at just the right time to take full advantage of the starch conversion.

Sound complicated? It is and it isn’t. Barley grains are steeped in water thoroughly to start the sprouting process, and after several days of warm humid conditions—about the time it takes for the sprouting end to grow to the length of the kernel—they are heated and dried (the process known as kilning). This stops the germination process and what’s left is malt—the starch- and nutrient-rich dried grain.

By itself this malted barley will produce a pale-colored beer. However, there are various methods maltsters (people who specialize in malting and treating the barley) have to add color: further kilning and roasting the grains will darken (some might even say burn!) the kernels which will add flavor and color to the finished beer.

The next step is mashing: converting the starches in the malted barley into sugars that the yeast will be able to consume. First the whole grains are ground up into a grist—small pieces, but not too small—and then they are steeped in hot water (for purposes of this article, we’ll simplify and say about 155°F). Enzymes that are already present in the malted grains will activate and convert the starches into sugars, and the resulting liquid will be a sweet wort: this is the essence of unfermented beer.

The wort is of course boiled with hops, cooled, and inoculated with yeast, which consume the sugars and excrete alcohol and beer flavors: what we know as beer.

Hops

Hops, as everyone these days knows (considering the popularity of the IPA and variant styles in recent years), are the bittering agent in beer. In fact, they are a bittering agent and a preservative: they have mild antibiotic properties and aid the prevention of the growth of microorganisms other than yeast. They have been used in beers since roughly the Middle Ages and in this day and age are considered an essential ingredient of beer.

Hops are flowers: the (female) flowering cone of the Humulus lupulus plant that counts among its relative the cannabis plant. It is the dried cones that are added to the boiling wort during the brewing process (though a style of beer than has emerged in recent years uses fresh hops during the boil).

Hops are used for two purposes in beer: for bittering, and for aroma, and in fact most varieties of hops are bred for one of these characteristics. The resins in hops that are responsible for these properties are acid compounds, known collectively as alpha acids and beta acids.

Alpha acids are the primary bittering component of the hops; higher levels of alpha acids indicate a higher bittering potential. Beta acids contribute to the aromatic properties of the hops, though are generally not considered in the same way that alpha acids are. (For instance, hop packages available to homebrewers always indicate the alpha acid percentage but almost never the beta acid content.)

During the boil, the alpha acids isomerize (transform) to release the bittering compounds into the beer; the longer the boil, the more fully the utilization of the hops—in other words, the longer they’re boiled, the more bitter the beer will be. Bitterness is roughly measured in terms of IBUs: International Bitterness Units.

(A quick point of reference: American macro lagers will have around 5 IBUs, Brown Ales will have around 25 IBUs, and the big beers—IPAs and so on—will have around 40-60 and up.)

Aroma hops are used, unsurprisingly, for the aromatic qualities they contribute to a beer: they are boiled only minimally or not at all, as boiling drives off those same aromatic compounds. Quite often a beer will be dry-hopped: those aromatic hops will be added directly to the fermenting beer after the primary phase of fermentation has completed, to give the beer an even stronger hop character in the nose.

There are a large number of hop varieties available, all of which impart their own character to the finished beer. While the bittering and stabilization of the beer is the primary motivation for using hops, these qualities are the bonus: thus we have such descriptors for hops in beer as “piney”, “herbal”, “spicy”, “green”, “floral”, “citrusy”, “earthy”, and many more.

Yeast

Yeasts are microorganisms of the fungi family that are responsible for converting the sugars in the wort to alcohol, carbon dioxide, and other compounds that collectively give beer its “beer” character: the process of fermentation. While there are thousands of varieties of yeasts that exist in the world, only a few are employed in the process of brewing beer.

Of course, when I write “only a few” what I mean to say is that there are a few strains of yeast that have been specifically cultivated for “ideal” beer brewing—but in practice, there may well be other strains (knowingly or unknowingly) at work.

Brewing yeasts are generally divided into two classifications: top-fermenting and bottom-fermenting. Top-fermenting yeasts (typical of ales, for example Saccharomyces cerevisiae) work at warmer temperatures than bottom-fermenting yeasts (typical of lagers, for example Saccharomyces pastorianus), and produce more esters and fruitier aromas. Bottom-fermenting yeasts work best at cooler temperatures and thus more slowly, often fermenting out more completely and leaving a cleaner, crisper character—all the characteristics of lager beer.

There is a third category of yeast(s) that is used in brewing with growing popularity: wild yeasts, most typically the Brettanomyces genus. These are the yeasts that spontaneously ferment the Lambics of Belgium, and American brewers have been experimenting with Brett yeasts to add sour and funky characteristics to their beers.

Much like the section on water and brewing regions of the world, various regions of the world have developed a “regional” strain of yeast: a brewing yeast with particulars characteristics that they have isolated and reuse. Often a brewery’s yeast strain is proprietary: the best example I can think of is Rogue, who developed and exclusively uses their own strain of yeast that they’ve dubbed “Pacman”.

This “regional yeast” concept extends to homebrewers, who have available to them various strains of yeasts from several vendors: Irish Dry Stout yeasts, Saison yeasts, German Altbier yeasts, even Lambic blend yeasts. Each yeast ferments the beer with its own set of characteristics: different flavors and aromas and even levels of alcohol produced. Thus the yeasts used in German Hefeweizens produce aromas of banana and clove—and so on.

Without yeast, beer would not be possible—but then, neither would wine, or bread, or yogurt, or sauerkraut, or many other things.

The German Reinheitsgebot (purity law) of 1516 decreed that only three ingredients were to be used in the production of beer: barley, hops, and water. (Yeast was added later after the discovery of microorganisms in the 19th century and its role in beer was more properly understood.) The Germans were on to something: not only was this a brilliant marketing tool, but it forced them to brew better beer without the trickery of various adjuncts. It’s not for nothing that some of the best beer in the world comes from Germany and is rooted in this tradition.

Water, barley, hops, and yeast—all you need to create the perfect beer.

Leave a Reply

Click here to cancel reply.

Username (required) :
Email (required) :
Web Site :
Comment :

CAPTCHA Code