Sonic Cherry Limeade Slush (Copycat)
Sprite, fresh lime, cherry syrup — drive-in nostalgia, frozen.
The Sonic favorite, rebuilt for the Slushi. Sprite gives the lemon-lime backbone, fresh lime juice keeps it sharp, and grenadine (or maraschino cherry syrup) brings the color and sweetness.
Bench-tested by the Will It Slush? team · Last revised August 2, 2026
Ingredients
Scale the batch — amounts update live in your units.
- Sprite (flat)475 ml
- Fresh Lime Juice90 ml
- Grenadine / Cherry Syrup90 ml
- Water290 ml
Method
- 1.Flatten the Sprite in a bowl (5 min).
- 2.Combine everything in the Slushi on Slush mode for ~50 min.
- 3.Serve with a lime wheel and 2 maraschino cherries on top.
Need the gear?
Amazon picksThis recipe is dialed in for the Ninja Slushi family. Pick your machine:
As an Amazon Associate we earn from qualifying purchases.
Notes from our testing
Sprite plus cherry syrup plus fresh lime — the fountain version's sugar is mostly the soda.
The drive-through original is lemon-lime soda, cherry syrup and lime wedges over crushed ice. Recreating it in the Slushi means the ice is now the drink, so the soda has to carry the sugar rather than being diluted by melt. Sprite at about 10 Brix does most of that job unmodified.
Our build is 10 oz of lemon-lime soda, 1.5 oz of cherry syrup, 1 oz of fresh lime and water to fill, landing near 11.5 Brix. Torani or Monin cherry syrup is around 60 Brix so that ounce and a half matters — measure it rather than pouring.
Fresh lime is not optional. Cherry syrup on its own reads as candy, and the whole identity of the drink is the sourness cutting through it. Lime cordial or bottled juice is sweetened and will push you over on sugar while giving you less acid.
For the adult version, 2 oz of vodka slots in with a half ounce more syrup to compensate. Past that you are trading the fountain flavour for alcohol and the balance falls apart.