Breaking Down the Highball
We're obsessed with highballs. And while a highball generally refers to a base spirit and a mixer served over ice in a tall glass, highballs in Japan almost exclusively refer to whisky sodas. When made properly, a highball is an extremely satisfying beverage that's crisp, refreshing, and pairs well with everything. And although this drink seems simple at a glance, there are several important aspects that contribute to a good highball.
Although you would never use a mature whisky to make a highball, that doesn't mean that the whisky you choose should be of poor quality. Blended whiskies, which can take between 3-10 years to make, are ideal for highballs because they're lighter, more subtle, less nuanced, and combine well with soda water. Multigrain whiskies, like Sunday's Whisky, are softer, sweeter, and have a more pronounced presence of ethanol. Adding soda water to this particular whisky is perfect because it brings the ethanol down, making the whisky easier to enjoy.
A good highball should always be cold. And like with most cocktails, ice is a very important component of a good highball. Although some highball styles like the Rockfish don't require any ice inside of the glass, ice cubes and ice rocks are both used to create this drink. Ice should be made from alkaline water compressed into layers to ensure clear cubes and rocks. Glasses with stacked cubes allow the entire beverage to remain cold and ice rocks keep the highball from diluting too quickly.
The glassware used to serve a highball is just an important as the contents inside. A highball glass can normally hold 250-375 ml and while the general style of the glass is consistent throughout most bars, the thickness of the glass is just as crucial. Thin glasses are the key to good highballs because they are more tactile. The thinner the glass, the more liquid hits the palate, which provides a heightened sensory experience.
Because most highballs use blended whiskies, soda water is important because it brings balance. Soda can help mask the "lesser" qualities of a whisky as well as and bring out the best, most dynamic flavors. In Japan, Wilkinson 'Tansan' soda water is the Suntory gold standard for highballs. This water comes from a source in Honshu near Kobe. It is a hard mineral soda water with good bubbles; these delicate bubbles bring texture to a highball and help provide a refreshing fizz after each sip.
Highballs don't necessarily need garnishes as the crisp soda water combined with delicious whisky is an experience that can be enjoyed as is. However, in some cases, a light garnish can help bring out different flavors in a whisky and a highball as a whole. Common highball garnishes include a lemon peel, citrus zest, mint, and shiso leaf.