Hops and Yeast Gives Craft Beer Flavor and Aroma

  • Post Author:

If you want to simply make beer it is done with a short list of ingredients: water, yeast, hops, and malted grain (most likely barley). These are the same ingredients used by the big guys. This short list sounds simple enough. Reality is, making beer is equal parts science and art; those latter 2 are the secret ingredients of making beer. Simply giving a person an easel, brushes and paints does not make that person a Rembrandt. If you want to make a fine beer you need to understand the science behind ingredients and how to put them together.

However, that perfect beer is about balancing flavor, aroma, bitterness, and mouthfeel. In trying to achieve any optimally balanced beer, interpreting, and tweaking a recipe is about understanding this science and art.

Today some are taking their artistry in new directions by experimenting with ingredients that are outside the traditional box. For example, some are using pine, fir, and spruce shoots to add bitterness and some different aromas to beer. But this practice dates to colonial times, so it is not entirely new. My daughter-in-law told me there are brewers experimenting with using grape skins for their tannins to add bitterness to beer.

When it comes to discussing beers, it doesn’t take long for the conversation to come around to hops. In the wine business it is about grapes. And yeast is the mystery ingredient; it is more difficult to understand yeast. Most of us have seen pictures of acres of hops growing or the mesmerizing shape of the hops cone, but we never see yeast because it is a single cell organism.

Hops primarily exist for imparting bitterness. There are 2 primary acids in hops-alpha and beta. The alpha acid gives beer the bitter taste profile. The second acid fills out bitterness. Historically the antimicrobial compounds in hops helped preserve beer.  This was an important attribute for sanitary and preservative reasons at that time. It is hard to believe beer has been around since 4,000 BC and recorded history of hops indicate they were used in 700 AD and the English were drinking beer with hops in 1400 AD.

As an aside, yeast has been around for an equally long time it is just that it was not discovered until the 1800’s.

In addition to hops there are a plethora of yeasts to choose from. The sheer number of varieties of hops and yeast strains stagger the imagination, together they offer limitless flavors, aromas, bitterness, and mouthfeel options.

“Americans have been growing hops since early colonial times, just not the number of varieties grown today. The first commercial N. American hop production was a 45-acre garden established in 1648 to supply a brewery in the Massachusetts Bay settlement”, notes Hops Growers of America. If you are interested in more hop facts, consider these:

  • 889 plants or “hills” make up one acre of hops.
  • In the Pacific Northwest, yields average about 2,000 pounds of dried hop cones per acre on mature hop yards, or a little over two pounds per hill (yields vary depending on variety and location).
  • Hops are typically sold in 200-pound bales (of course those are serious brewing operations).
  • A bale will yield between 135 – 800 barrels of beer (31 gallons in a barrel), depending on the recipe.

Source: Hop Growers of America

When a person discovers that perfect beer, that experience will probably be short-lived; personal tastes preferences do change. Like wine consumers, beer taste preferences do change which motivates consumers to explore new offerings. Further, the sheer magnitude of style variations will foster experiments for new beers.  Who would have envisioned a Peanut Butter Stout or using pine shoot or grape skins to make beer?

One change in progress is the non-alcoholic beer category. This trend has not worked out well for wine, but we will see about beer.  Alcohol does impact flavor and that is a big issue whether it is wine or beer.

As the old expression goes-Nothing is easy and if it were everyone would be doing it. Brewing is no exception, a slight change/misstep in execution or ingredient selection can result in unintended consequences.  If there are any doubts, acquaint yourself with the story of the demise of the largest American brewery in the 1960’s—Schlitz-The Beer That Made Milwaukee Famous.

Tragically, after senior management changes, the new management team thought they could save money by using cheaper ingredients and employ short-cuts in production. (Ultimately, they were accused of selling “green” beer due to shortened fermentation times.) The consumer instantly recognized some changes in the product and did not like the changes. It was not long before consumers understood something was wrong with their favorite beer. This incident validates another adage: If it isn’t broken don’t fix it. Unintended consequences.

Deciding what is the best beer is a subjective decision. I did some research a few years ago and found there were 17 different considerations that came into play in deciding what wine was a person’s favorite. Basically, such things as: environment, age, experiences with various wines, influences from other people, visits to wineries, mouthfeel, aromas, etc. formed a person’s preference. Beer is not that much different when it comes to subjective decisions on that ideal beer.

The current trend in beer is the hoppy forward sensory perception of bitterness as well as taste/flavor. For consumer demanding the fresh bitter taste of hops, selecting the right hops varietal is critical. The choice of hops to get that right level of bitterness are many.  It is the high acid content in individual species of hop cones that will deliver that precise bitter taste. Then the trick is to choose the hops that will deliver a desired aroma profile.

The numeric value of bitterness is the IBU number. The IBU scale is from 1 to 100. It is the bitterness introduced into beer from the hops that regulates the desired sweetness in the product.

“Just as there are dozens of grape varietals used for winemaking, there are a ton of different kinds of hops available to brewers. And just like with wine grapes, hops of different strains and from different growing regions bring different flavors, aromas, and bittering capabilities,” comments Caitlin at KegWorks 2017.

America and Germany are the mecca of hop development and research. In the US, the center of the hop world is Washington, Idaho, and Oregon.

Hop varieties also have a pedigree and growers thrive on the reputation surrounding the quality of their hops, the better the hop pedigree and a grower’s reputation, the greater the demand. As in most things demand drives the price. It is speculated that some hop varietal cones have sold for a high of $20-25 per pound. The average in 2019 appears to be $5.68/pound. Last year growers in the US produced 113.5 million pounds of hops and that is an increase of nearly 90% over 2012 and a 7.5% increase over 2018.

The impact of hops on the beer making process is really determined by the style. A rough rule of thumb is 200 pounds of hops (1 bale) makes 20 barrels.

Here is a breakdown, by style, of hops (in pounds) used in producing a typical keg of beer (1,984 ounces):

Amber                                  0.17

Brown Ale                           0.52

Imperial IPA                       3.80

IPA                                         1.00

Pale Ale                                0.56

Stout                                     0.30

Source: Hop Growers of America

Lastly, the essential oils in hops dictates the aroma value, along with some support from yeast. These oil esters are unique to each variety of hops. Some oils will produce floral, citrus, or earthiness tones. There is an art form to working with the essential oils to bring out the desired aroma. Too much heat for too long will destroy the aroma esters in hops. Brewer experience seems to be a significant factor in bringing out the character of essential oils.

There are approximately 80 active varieties of hops to choose from and more are being developed constantly. The actual count of hop varieties may be closer to 180.  This is like grape varietals in winemaking; there are hundreds of varietals that are planted, and more are being developed by universities and labs all over the world. In 2019, the US was the largest producer of hops followed closely by Germany.

Simply put, hops can be split into three main categories: bittering, aroma, and dual. Bittering hops tend to have a high amount of acid in them and impart that recognizable bitter flavor onto the beer. Aroma hops have less acid but a more pronounced flavor and aroma and are used to make the beer taste and smell a specific way. Most beer recipes call for both kinds of hops. Dual hops tend to have a mid-range to high amount of acid and a good smell and aroma and can be used for both aroma and bittering. If you want to brew a beer with just your homegrown hops, one of these dual hops plant types is a good choice,” says Liz Baessler. Choose your hops wisely.

Moving to the subject of yeast.

Yeast, a single cell organism, is used to turn the various sugars in malted grain/wort into alcohol. The importance of yeast research is illustrated by also looking at the wine industry.  As an example, in 2019 a university in Spain claimed to have developed a yeast strain that could impart the same taste and aroma as aging wine in an oak barrel. This points out the flexibilities yeast brings to the table relative to fermenting. Imagine a microscopic cell has this much influence on making alcohol, CO2, the myriad flavor and aroma options and mouthfeel in beer.

“Yeast can also take credit for the classification of the beer styles. Brew masters pick a yeast according to the recipe or the style of beer they want to make. Yeast is identified as either an ale yeast or a lager yeast,” according to Beer Cartel blog.

Yeast is a complex ingredient in beer. There are hundreds of yeast strains used in beer and each one offers its own personality and characteristics. Some are specifically suited to consume select sugars in the wort and some have stronger endurance to perform that task.

Today there are many manufacturers of pure brewer’s yeast strains. It is important to realize yeast also occurs naturally in the environment and wild yeast in not necessarily good in brewing. For this reason, early brewers had real problems controlling consistency of the performance of their yeast.  Yeast is added after the wort boils (with the hops) and after the wort has cooled (temps are dictated by style). Yeast is so important that some brewers are very secretive about the yeast variety they use.

Yeast bought for home brewing is often sold by the number of cells in a vial or package. For example, a small bag of a pure yeast strain will contain 100 million cells and that would generally be enough for 5 gallons of a finished beer. Retail cost is about $10.00.

Dr. Linda Bisson has spent much of her life doing research on yeast. Dr. Bisson say there are thousands of yeast strains and many strains are naturally occurring in the wild. Mentioned previously, the big contributor to mouthfeel is the way specific yeasts react with specific sugars in the wort- specifically dextrin sugars.

People have asked if bread or wine yeast can be used in beer fermentation. The short answer is no, at least not practically. However, a more educated answer is from Mr. Denny Conn, “You can use any kind of yeast to ferment a beer, but the problem lies in the results. Wine/champagne yeast ferments different group of sugars. (The subject of sugars is a complex subject when it comes to yeasts consuming the sugars in wort.) Wine yeast does not ferment malt triose, one of the main sugars in beer wort. The result is that you’re left with beer that doesn’t quite taste like beer.”

“Hops tend to get all the glamor and attention these days, I strongly believe that the real stars of the show—what makes beer fascinating, delicious, and perhaps even nutritious, is yeast,” says Joseph Lavoie-Beer Craftr (sic).  Lavoie explains that before Louis Pasteur’s work in yeast research in the mid 1800’s, brewers knew they had to use the leftover sediment from the previous brew to make the next batch, they just did not know it was yeast that made beer concoction come to life.

According to “Beer Magazine”, different strains of yeast behave differently, so that makes it possible to divide the world of beer according to the yeast. Sixty or more defined beer styles can all be sorted by their yeast into two broad families: the ale family of yeasts and the lager family-top fermenting (cooler temps) and bottom fermenters (warmer fermenting temps) respectively.

To illustrate just how complex the selection of yeast has become, I went to a large manufacturer of brewer’s yeast and counted their yeast offerings for making a few popular styles.  Here is what I found: American Ale-32 varieties; British Ales-45; Belgian Sour Ales-26 and IPA-36.

Here is a sample profile they offer to help in selecting a yeast.

wYEAST aMERICAN aLE #1056

  • Type:Liquid
  • Flocculation:Low/Med
  • Attenuation:73-77%
  • Temperature:60-72°F, 15-22°C
  • Flavor:Exceptionally clean, crisp flavor characteristics with low fruitiness and mild ester production. A very versatile yeast for styles that desire dominant malt and hop character. This strain makes a wonderful “House” strain. Mild citrus notes develop with cooler 60-66°F (15-19ºC) fermentations. Normally requires filtration for bright beers.

Because wort sugars are ready-made for yeast, one of the complexities of brewing is understanding the myriad types of sugars and their chemical structure. Wort is what gives yeast a foundation to bring beer into its own. The subject of the relationship of sugars and yeast is extraordinarily complex.

Noted earlier, yeast also contributes to beer’s flavors and aromas. It also can aid in making beer clear through the process of flocculation. In flocculation yeast cells form together and settle/drop out leaving beer clearer. Further, yeast can highlight the maltiness and aroma profiles while adding to fruitiness that hops imparts. Yeast will also impact sweetness or dry sensation and mouthfeel in the finish.  Mouthfeel is a huge sensory queue in appreciating a fine beer.

Because yeast and hops do similar things relative to flavor and aroma it is important to understand how each variety of hops and yeasts will impact a style. If you really want to fully enjoy the experience in consuming a fine beer it is helpful to at least understand some of the science.

In the 1880’s a scientist isolated a pure strain of yeast that was suitable for lager brewing, as opposed to ales. This is an example why research is always moving ahead in yeast development.  Even the miners of the California Gold Rush era recognized the special characteristics of a bread made by a bakery in San Francisco. The Boudin family made a special sourdough bread using a special yeast the family discovered.

Beer is unique unto itself because craft beer can and is being produced for regional and national markets. The beers we enjoy today with new flavors and aromas are due to the creativity in beer making  processes and ingredients. New styles have brought beer into new social settings.  Think about seeing beer as a center piece at food pairings, even fine dining establishments, and celebratory gatherings.

Mr. Koch of the Boston Beer Company has made a beer that he says will stand up to any champagne. “Champagne taste with a beer budget? Thankfully, these days, you don’t have to shell out hundreds of dollars to sip that sweet sparkling wine – in fact, you can have the same champagne taste and mouthfeel in your favorite type of beer,” says Kaitlyn McInnis-Editor, Ask Men.

“Thanks to the rise in craft beer, more and more breweries are experimenting with funkier ingredients and brewing methods, including using champagne yeast in their brews! This out-of-the box brewing results in the same umami-packed taste you love in champagne but for a fraction of the cost,” says McInnis.

 Different Beers, Different Strokes for All the Folks!

Cheers!