While unusual, chasing a shot of whiskey with cucumber pickle juice, better known as a pickleback, is a popular way to gulp down burning alcohol, and there’s a good reason why.

Pickle juice, made of vinegar, water, and salt, tastes salty and sour. On the contrary, whiskey has a woodsy, peaty flavor with bitterness and a burning sensation from the alcohol.

The salt in pickle juice can play a major role in enhancing desirable flavors in the whiskey — like sweetness and fruitiness — while suppressing undesirable ones, like bitterness.

Since pickle juice is alcohol-free, it can also help cool down the burning sensation caused by the whiskey. Lastly, the sourness from the vinegar acts as a great palate cleanser.

Sweet pickle juices go well with sweeter whiskeys, saltier varieties work well with American whiskeys and smoky mezcals, while spicy pickle brines are great chasers for tequila.