Having become recently enamored of beer, I keep asking: What is it that makes this so delicious? Here’s DCist’s review of what factors count in determining the flavor of a beer’s "soul":
Hops are the true id of the formula. They have no concerns other than pleasing our taste buds with unabashed, oily satisfaction. They want to fulfill desires of refreshing bitterness with a devil-may-care attitude to all other flavors in our adult beverage.
Water and yeast control the workflow, or ego, on the beer. They consciously dictate a direction in which the beer develops character, working with the id and super-ego to delegate fermenting style and create alcohol to blur the line between conscious and subconscious.
Finally, malts provide the restraining flavors that are needed to balance the brutish id. Malts leash the unruly hops and provide the super-ego balance that our beer psyche wants. As we have already talked about the hopsand malts areas of the brain brewing process, put on your best nerd outfit (lab coat preferred), and strap in for a discussion of the underappreciated workhorses of our beers: water and yeast.
For hundreds of years, commercialized brewing has known the effect water composition has had on the taste of its beers. Cities like Dublin, London, and Munich have “hard” water that lends itself to dark and robust beers. This hardness is attributed to the minerals the water collected as it passed through the soil. Whereas cities like Burton-on-Trent (home of Bass) and Pilsen (Pilsner Urquell) have very “soft” water that lends itself to pilsners and pale ales.
The two main factors affecting water for brewing are calcium and bicarbonate, with calcium being the most important for a number of reasons. Calcium increases enzymes in the wort (unfermented beer) that makes the wort more fermentable by increasing sugar levels. More sugars mean more food for yeast to turn into alcohol. Calcium also leads to a lower pH in the beer, which reduces contaminants, protects enzymes, and reduces unwanted flavors and haziness. Bicarbonates are monitored closely: in excess, they increase the pH of beer more than calcium can lower it, so all those benefits are negated.
Yeasts are the unsung heroes of the beer world. Often it is overlooked, but yeast actually creates the alcohol and many of the flavors we love in beer. Generally, there are two types of yeast: top fermenting and bottom fermenting. Top-fermenting yeasts are used for ales, porters, stouts, and wheat beers. As they ferment the wort at warm temperatures, they rise to the top and create many of the flavors you associate with these styles along the way. Bottom-fermenting yeasts are used to ferment lagers at cooler temperatures and thus grow at a slower rate. This slower rate lends itself to more of the restrained flavors as you have come to expect from your favorite easy-drinking lager.
Some of the flavors you think come from other ingredients might becoming to you from the byproducts of the yeast variety. Here are some of the common flavors that are yeast byproducts:
Acetaldehyde (green apple aroma/cidery flavor)
Diacetyl (taste or aroma of buttery, butterscotch)
Dimethyl sulfide (DMS) (taste/aroma of corn, cooked veggies, even oyster)
Ester (flavor/aroma of bananas, strawberries, apples, or other fruit)
Phenol (flavor/aroma of medicine, plastic, Band-Aids, smoke, or cloves)
Sulfur (reminiscent of rotten eggs or burnt matches)
Obviously some of these are more desirable than others, but several of the potentially negative byproducts can add different dimensions in conjunction with others’ flavors. For example, many German Hefeweizens are known for their banana and clove flavors, but you wouldn’t want those same properties in your IPA.
Also worth noting is a growing movement in American craft beer to use wild yeast strains (such as theBrettanomyces Lambicus strain) from the natural yeasts that float around in our air. This has been the traditional method of fermentation in many parts of France and Belgium for centuries. They lead to a sour profile that may be odd and maybe even a bit unsettling upon first sip, but once properly introduced, can open up a while new world of flavors that you wouldn’t think you enjoy. Luckily for us in D.C., many Lambics can be found in both stores and quality beer bars all over town.