casper sour

1 1/2 oz Vodka (Vesica)
1/2 oz Simple Syrup (1:1)
1/4 oz Rice Wine Vinegar

Stir with ice and strain into a cocktail glass. Garnish with a lemon twist.

For Thursday Drink Night on Mixoloseum last week, the theme was "Animosity." The concept was to use an ingredient that you hate or neglect. I first started in my liqueur section and pulled out the dustiest of bottles including Chambord, Parfait Amour, and a few others that get little use. Inspiration still did not hit. I took a step back and considered vodka. Even for Mixology Monday's vodka theme, I chose a robustly flavored drink, the Sputnik, to present. There, the vodka helped to dilute the intensity of Fernet Branca in a Sour-type drink. Joking around with the concept of a less flavored drink, someone on Mixoloseum came up with the name of a "Casper" (the Friendly Ghost) Martini. From there, I toyed with the idea of a minimalist Sour drink.

I first considered making a solution of citric acid powder, but I was unsure of the concentration to use (note: for future reference, lemon and lime juice are 5-6% citric acid or around 1.1 grams per ounce of water) and how I could balance it with simple syrup. Instead, I thought about vinegar. From my experiments and notes on vinegar-based fruit shrubs, I felt comfortable on how to balance the vinegar's acid content (BTW: vinegar is also at a 5% concentration, albeit with a slightly different pKa) with sugar. While plenty of other people have used flavored shrubs and gastriques, what about an unflavored one? Or one that just used a flavorful vinegar alone? I first looked at my apple cider vinegar but it was near the end of the bottle and full of particulates; next to it was a nice bottle of rice wine vinegar and I decided to give it a go.
For a drink name, I harkened back to the Casper idea and dubbed the experiment the Casper Sour. The drink's nose was a lemon oil aroma that meshed well with the hints of the rice wine vinegar. Upon tasting it, I was rather pleased with the savory sweet and sour sip and the dry rice wine swallow. Indeed, for what I was expecting to be a flavorless yet crisp drink had a beautiful light sake sort of effect. While I have never tried or comprehended the allure of a Dirty Vodka Martini, the Casper Sour gave a glimpse at why people might enjoy something like that especially since most olive brines contain vinegar in addition to the salt.