Blue Raspberry Syrup Recipe
Syrup · 2025-04-22 · 5 min read · by Emily
Blue raspberry syrup is one of those things that sounds fake until you taste it — because technically, it is. There's no such thing as a blue raspberry in nature. The flavor was invented in the 1970s when candy companies needed a color that wasn't already taken by strawberry (red) or grape (purple). They paired raspberry flavoring with blue dye and the rest is slushie history.
But here's the thing: the flavor works. It's tart, sweet, and instantly recognizable. And making it at home means you can use real raspberries for actual fruit flavor instead of the purely artificial stuff in store-bought versions. You just add the blue color separately.
Ingredients
1 cup fresh or frozen raspberries. 1 cup granulated sugar. 1 cup water. 1 teaspoon citric acid (or 1 tablespoon fresh lemon juice — citric acid gives a cleaner tartness). ½ teaspoon raspberry extract (optional, for a more intense flavor). 3-5 drops blue food coloring (gel food coloring gives a deeper color with less liquid).
How to Make It
Combine the raspberries, sugar, and water in a small saucepan over medium heat. Stir until the sugar dissolves completely, then let it come to a gentle simmer. Cook for about 8-10 minutes, pressing the raspberries against the side of the pan with a spoon to release their juice.
Remove from heat and let it cool for 5 minutes. Strain through a fine-mesh sieve into a clean jar or bottle, pressing the pulp to get all the liquid out. Discard the seeds and pulp.
Stir in the citric acid (or lemon juice) and the raspberry extract if using. Then add the blue food coloring drop by drop until you get the shade you want. Start with 3 drops — you can always add more, but you can't take it back. The syrup should be a vivid blue-purple, not navy.
Let it cool completely before using. Store in a sealed bottle or jar in the refrigerator. It keeps for 3-4 weeks.
What to Use It For
This syrup works anywhere you'd use simple syrup but want that blue raspberry hit. Pour it over shaved ice for homemade snow cones. Mix it into lemonade for a blue raspberry lemonade that actually tastes like fruit. Stir it into club soda with ice for a quick Italian soda.
For cocktails, it pairs surprisingly well with vodka and a splash of lemon juice — basically a blue raspberry lemon drop. It also works in a gin and tonic if you want something visually dramatic. Two tablespoons per drink is usually the right amount.
Tips That Make a Difference
Use gel food coloring instead of liquid. Liquid food coloring requires way more drops to get a saturated blue, and all that extra liquid dilutes your syrup. Gel gives you vivid color with just 2-3 drops.
Citric acid is worth buying if you plan to make syrups regularly. It adds that sharp, clean tartness that lemon juice can't quite replicate — the same pucker you get from sour candy. You can find it in the canning section of most grocery stores or online for a few dollars.
If you want a completely smooth syrup with zero pulp, strain it twice — once through the mesh sieve, then again through a coffee filter or cheesecloth. The second pass catches the fine particles that make it slightly cloudy.
The Cocktail Version
Blue Raspberry Vodka Lemonade: Fill a tall glass with ice. Add 1.5 oz vodka, 2 tablespoons blue raspberry syrup, and 4 oz fresh lemonade. Stir and top with a splash of club soda. Garnish with a lemon wheel. It looks like a pool party in a glass and tastes like summer.
For a frozen version, blend 1.5 oz vodka, 2 tablespoons syrup, ½ cup ice, and 2 oz lemonade until smooth. Pour into a coupe glass. It comes out looking like a blue slushie for adults.