Substitutes:

• Bourbon: If you don't have bourbon, rye whiskey can be a good substitute. It has a spicier profile than bourbon, but it still works well in this cocktail. You could also use brandy for a different flavor profile.
• Lemon Juice: If fresh lemons aren't available, you can use bottled lemon juice, but I always prefer fresh when possible. Lime juice can also work in a pinch, giving the drink a slightly different, but still delicious, tang.
• Simple Syrup: If you're out of simple syrup, you can make your own by dissolving equal parts sugar and water over heat. Alternatively, honey or agave nectar can be used for a more natural sweetness.

Making a Pitcher of Bourbon Sling:

• Scale: To make a pitcher that serves 8, multiply all the ingredients by 8. That would be 16 oz of bourbon, 8 oz of lemon juice, and 4 oz of simple syrup. Top with club soda as needed.
• Mix: In a large pitcher, combine the bourbon, lemon juice, and simple syrup. Stir well.
• Serve: Pour the mixture into ice-filled highball glasses, top with club soda, garnish with a lemon slice and cherry, and serve immediately.

Making it Non-Alcoholic:

• Bourbon Substitute: Use a non-alcoholic bourbon substitute; several brands are available that mimic the flavor of bourbon without the alcohol.
• Proceed As Usual: Use this non-alcoholic substitute instead of the regular bourbon, follow the original steps, and enjoy a non-alcoholic version.

Making it Vegan:

• Simple Syrup: Ensure your syrup is made with vegan-friendly sugar, some producers may use bone char during production.
• Garnish: Skip the cherry garnish if it's been processed with non-vegan ingredients (some maraschino cherries are colored with cochineal extract derived from insects). Opt for fresh cherries instead.