Butterfly Pea Flower Cocktail (Purple Tom Collins)

Impress everyone you know with the ultimate special effects: A color-changing Butterfly Pea Flower Cocktail. This Tom Collins-style cocktail starts with a true blue syrup, made with real flowers, that turns purple and pink when it meets citrus. Watch the hue shift before your eyes.

About this Butterfly Pea Flower Cocktail recipe

A cocktail with a dramatic flair can steal the show at happy hour. Having a drink that is as stunning as it is delicious is always a great conversation starter, like this wintry snow globe cocktail or a cozy hot cocoa ball.

But in spring in summer, turn to a drink made with butterfly pea flower syrup. It is naturally earthy in flavor and has a deep blue hue. But when mixed with citrus, it turns purple, then swirls into bright pink! If you’re mixing paint, blue mixed with yellow should turn green, so it is mind-boggling to watch in real time.

You can find gin that’s infused with these magical flowers and gives a similar effect, but the using the syrup is more versatile and cost-effective because you can use it with other spirits and aren’t limited to the botanical notes of gin or the price of a single bottle.

In the case of this Butterfly Pea Flower Cocktail, it’s like a Tom Collins drink. You can make it with any gin or vodka, or even swap in rum or tequila if you want to experiment — the Collins style is ideal for creativity! However you make it, this libation is light, bright and perfect for making an impression next time you mix drinks for friends.

More sweet gin drinks: Bee Sting • Bee’s Knees • Classic Gimlet • Bramble

What are butterfly pea flowers?

Butterfly pea flowers are vibrant blue blossoms from the Clitoria ternatea plant, native to Southeast Asia.

They’re commonly used to make herbal tea and natural food coloring, thanks to their intense indigo pigment. These flowers are prized for their ability to change color when the pH shifts — turning purple or pink when mixed with something acidic like citrus juice.

You can order dried butterfly pea flowers ^* online or find them at specialty shops. The flowers have a mild, earthy flavor that’s slightly floral and a little grassy.

Tools & glassware

You will need a medium saucepan to prepare this butterfly pea flower syrup. A fine-mesh strainer ^* will help to strain out any solids, keeping your syrup smooth.

The other thing you need is something to store it in. You’ll want to get an airtight container to keep your syrups in — they must be stored in the fridge. A set of mason jars is a wise investment if you like making syrups. You can even add a mason jar pour spout lid to your jar for easy pouring.

For the drink, you’ll want a cocktail shaker ^*, a jigger ^* and a Hawthorne strainer ^*, plus highball glasses ^* to serve the drinks. I used Collins ice cube trays to make long spears of ice that keep the colors bold and undiluted.

favorite highball glasses

art deco highball glasses

Buy Now →

fluted highball glasses

Buy Now →

heavy base highball glasses

Buy Now →

^*

Ingredients

Stock up on these simple ingredients to make this butterfly pea flower cocktail at home:

• dried butterfly pea flowers ^*: Sometimes sold as butterfly pea flower tea, these dried blue blossoms are known for their striking color and natural pH-sensitive properties. You can easily order them online, where they’re often sold in loose-leaf tea form.
• sugar: Any type of sugar will work because it is melted down once heated. Typically for colorful syrups, I recommend cane sugar or granulated sugar.
• water: Filtered water or distilled water will give you the best, purest results, but tap water is totally fine.
• gin: London Dry Gin or Old Tom Gin would both work well here. Plain vodka also works, if you’re not a gin fan. Then this drink is essentially a purple Vodka Collins.
• lemon juice: Fresh lemon juice gives off the best, sweetest flavor in a cocktail if you have it on hand. Feel free to use a good quality lemon concentrate if you need a shortcut.
• club soda: You can use plain sparkling water or flavored fizzy water to create your own flavor combinations.

Best gin for cocktails

Traditionally, the Tom Collins is made with Old Tom gin. However, London Dry gin is very common.

Old Tom is sweeter and more full-bodied, whereas London Dry is lighter. The latter is what most people know as gin. One of my favorites is Hendrick’s Gin, with notes of rose and cucumber that perfectly complement the sweet lemon flavor.

Since we are using the purple butterfly pea flower syrup, you don’t need to use a purple gin. However, it’s a good swap for the gin if you only have a plain syrup to work with. This will create a cocktail with the very same special effect.

Substitutions & variations

No butterfly pea flowers? If you wish, you can purchase butterfly pea floral extract to use instead of the syrup, but you’ll still need to add some kind of a sweetener like plain simple syrup. You could also use purple gin made with the flowers for a similar effect.

Butterfly pea flower French 75: Using champagne instead gives you a French 75. This Elderflower French 75 has an additional splash of St. Germain, giving off a sweet, floral flavor, which would only enhance the delicate flavors of this drink.

Non-alcoholic version: Swap the gin for a zero-proof alternative. These are some of our favorites:

zero-proof gin alternatives

Ritual gin alternative

Buy Now →

Seedlip Garden 108

Buy Now →

Seedlip non-alcoholic spirits

Buy Now →

^*

Butterfly pea flower syrup

This cocktail starts with a homemade simple syrup made from dried butterfly pea flowers.

First, make the syrup. Add butterfly pea flowers and water to a medium saucepan and place over medium-high heat. Bring to a boil, then reduce to a simmer for 15 minutes. Remove from heat.

Strain the hot liquid through a fine-mesh sieve ^* to remove the flowers and any solids. Measure the remaining liquid, then return it to the pot over medium heat. Measure out the same amount of sugar as the liquid. Stir until completely dissolved.

Remove from heat and let cool completely. Store in a clean, food-safe, airtight container such as a mason jar in the refrigerator for up to 1 month.

Instructions

Here’s the best way to make a butterfly pea flower cocktail and get the most stunning visual effect:

Once you have the syrup, you can make the cocktail! Grab a cocktail shaker ^* and fill it with ice. Add gin and lemon juice. (Don’t add the syrup yet!)

Shake well. Strain into a Collins glass ^* filled with ice.

Top with club soda and a When you’re ready to serve it, serve it with a shot glass ^* of the syrup.

Drizzle the butterfly pea flower syrup over top and watch the color change! Stir gently. Add a mint sprig and lemon slice.

Storage tips & shelf life

Since this homemade, floral simple syrup doesn’t have a stabilizer, it is best to store it in an air tight container in the fridge. It will last up to 2 weeks when stored in the fridge.

You can also freeze simple syrup! If you need more ideas, I have a whole post with the best tips and tricks on how to store simple syrup.

Food pairings

A Collins drink is a classic refresher cocktail that pairs with so many foods. The lemon flavor goes especially well with seafood, such as popcorn shrimp, fried fish or a Caesar salad.

This drink would also go well with a light appetizer like a charcuterie board or spicy shishito peppers. For sweets, anything lemon or floral would be perfect, like lemon bars or Earl Grey cookies.

FAQ

More floral drink recipes

• Lavender Latte
• Elderflower Rose Gimlet
• Rose Champagne Cocktail
• Hugo Spritz