Why would anyone mix good beer with anything? As it turns out, beer can add a complexity to simple cocktails without adding a lot of alcohol content. Called "hoptails," these mixtures achieve unique taste profiles that can be hard to recreate without beer.
Though this practice is probably most commonly associated with dumping a beer into a frozen margarita, it’s recently become popular in upscale cocktail bars. To introduce this trend, we’ve put together a primer on fermentation and some flavor compounds common to beer.
Brew Something Up
Each beer’s flavor profile comes from a combination of its ingredients and fermentation. At its simplest, the four main ingredients in beer are barley and/or wheat, hops, yeast, and water.
The first step in brewing beer is malting the barley or barley/wheat mixture. Here, the grains are germinated (sprouted) and then dried in a process called kilning or heat drying. This step preserves enzymes that will later break down starches and proteins.
It’s also where much of the beer’s character is created. Using a lower temperature results in light malts popular in lighter styles of beer, whereas high temperature kilning denatures more of the natural enzymes and breaks down complex proteins and starches into amino acids and sugars.
The malt is then ground and loaded into a temperature-controlled vessel called a mash tun. Water is added, and the tun is heated to different temperatures where the enzymes will begin breaking down starches into glucose and maltose.
After mashing, the grain and water mixture is filtered. Called "wort," this solution is then boiled to sanitize it. Hops are added during this stage. Each varietal of hops has a slightly different chemical makeup. This diversity means that resultant beers have the potential for many, many different taste profiles.
For bitterer beers, hops are added early in the boil. Hops contain α-acids, a class of chemical compounds that isomerize (chemically rearrange) when boiled. For less bitter, often more aromatic beers, hops are added later in the boil or as the wort is cooling.
Choosing a particular strain of yeast for fermentation is one of the last big decisions. In brewing, a strain of Saccharomyces cerevisiae breaks the wort’s sugars down into ethanol and CO-2. During this process, a series of side reactions also occurs to form other products such as esters and ketones that can have a big impact on the beer’s final taste.
Here’s a short list of some common taste compounds found in beer:
• 4-Vinyl guiaicol smells like cloves and is common in Hefeweizens.
• Acetaldehyde occurs most commonly in under-fermented beers. This little compound is usually described as tasting of green apples.
• Diacetyl is often described as a buttery or butterscotch-y smell. Concentrations of this compound tend to increase with the age of the beer.
• Dimethyl sulfide gives some beers the smell of canned vegetables.
• If you’re smelling some red apple and anise, it’s probably the ethyl hexanoate.
• Geraniol is the compound that gives beers a geranium- or rose-like floral taste.
• Ever had a beer that tasted or smelled a bit like fake bananas? It was probably the isoamyl acetate.
• Limonene is one of the many taste compounds named for the food in which it’s most commonly found. It’s also what gives some beers a citrusy character.
• Lactic acid is what gives some sour beers their sourness.
• Linalool is most commonly associated with beers’ hop aroma.
• Myrcene is the infamous green hop aroma. Also described as resinous, herbaceous and balsamic, this compound can get a bit overpowering in high levels.
Hit the Lab
Craft beers’ unique taste profiles win over or push away drinkers every day. To experiment with hoptails, first taste the beer you’d like to use. Is it citrusy? Rich? Coffee heavy? Bitter? Consider some simple cocktails that are topped with soda. Which beers could easily replace the soda? For example, a light, not-so-bitter IPA could easily replace the soda in a Tom Collins, yielding an easy hoptail.
Likewise, a cucumber or raspberry saison would be a delicious addition to a Pimm’s Cup. Since the only two requirements for this drink are that it contain Pimm’s and be served in a cup, the possibilities are endless. Be careful—if a beer is sweeter, you may have to add a bit more citrus juice to balance it.
Summer Pimm’s Cup
Several thinly sliced pieces of ginger root
1 oz simple syrup
1 oz lemon juice
2 oz Pimm’s No. 1
Beer of your choice
Muddle ginger slices in a cocktail shaker. Add all other ingredients and ice. Shake vigorously for 20-25 seconds or until chilled through. Strain into a chilled collins glass full of ice and top with cucumber or raspberry saison (a pale ale) or other beer. Garnish with a mint sprig and a straw.
Dr. Tracy Hamilton’s presentation on zymurgy (beer chemistry) was a huge resource for this article.