What is Shamrock Shake syrup made of?

The signature minty green Shamrock Shake from McDonald’s has become a staple menu item to celebrate St. Patrick’s Day. This popular frozen drink is made with vanilla soft serve, Shamrock Shake syrup, and is topped with whipped cream. But what exactly is in the magical minty syrup that gives the Shamrock Shake its iconic flavor? Here we’ll take a look at the ingredients that go into making this fan favorite beverage.

The History of the Shamrock Shake

The Shamrock Shake was first introduced by McDonald’s in 1970. It was originally created to celebrate St. Patrick’s Day and was only available for a limited time during the holiday season. The shake was an instant success and gained a cult following among customers who looked forward to its annual return to the menu.

Over the years, McDonald’s has brought back the Shamrock Shake for longer periods of time due to popular demand. While the exact dates vary each year, today you can typically enjoy a Shamrock Shake at McDonald’s from late February through the end of March.

Main Ingredients in Shamrock Shake Syrup

McDonald’s keeps their exact Shamrock Shake syrup recipe a secret. However, based on reviews of the drink’s flavor profile, we can make some educated guesses about what goes into that minty green syrup:

  • Sugar – The base of the syrup is likely high fructose corn syrup or plain sugar to provide sweetness.
  • Corn syrup – Thick, viscous corn syrup gives the syrup body and texture.
  • Mint flavoring – Natural and/or artificial mint flavors like peppermint and spearmint oil provide the dominant mint taste.
  • Green food coloring – Vibrant green food dye gives the syrup its iconic green color.
  • Stabilizers and emulsifiers – Ingredients like xanthan gum and polysorbate 80 help evenly distribute flavors and thicken the syrup.

In addition to these key ingredients, McDonald’s likely adds some natural mint flavors like actual mint leaf extract or mint ice cream to boost the authentic mint taste. But the basics of the syrup consist of sugar, corn syrup, mint flavoring, food coloring, and stabilizing agents.

The Importance of Natural Mint Flavor

One of the keys to replicating the perfect Shamrock Shake at home is using real mint flavor. While artificial mint extract can get close, using real mint like peppermint leaves, mint tea bags, or even mint ice cream makes a big difference.

Here are some options for adding natural mint flavor to homemade Shamrock Shake syrup:

  • Infuse mint tea bags or fresh mint leaves into simple syrup while heating it.
  • Add a few drops of pure peppermint extract or peppermint oil.
  • Blend in mint ice cream – this adds natural mint flavor from the leaves as well as a creamy texture.
  • Use creme de menthe (a mint flavored liqueur) for an extra kick of mint.

Experiment by adding a combination of natural mint extracts and infusions to find a balance you enjoy.

Coloring the Syrup Green

After you’ve nailed down the perfect mint flavor, the next step is coloring the syrup an authentic kelly green color. Here are some safe options for coloring your shakes green at home:

  • Liquid green food coloring – Use standard dye or natural options.
  • Matcha green tea powder – For a natural green hue and extra antioxidant boost.
  • Spirulina powder – This antioxidant-rich blue-green algae turns things vibrant green.
  • Liquid chlorophyll – Made from leafy greens, it adds health perks and green color.

Start with a small amount of coloring and adjust to the desired shade of green. Too much coloring may lead to an unnatural looking neon green.

Thickening the Shake Syrup

To achieve the perfect thick, spoon-coating consistency of Shamrock Shake syrup, you’ll need to add a thickening agent. Here are a couple options:

  • Cornstarch – Mix 1-2 tablespoons cornstarch whisked into the cooled syrup to thicken.
  • Xanthan gum – Add 1/4 to 1/2 teaspoon of this powerful thickening agent.
  • Ice cream – Fold in soft vanilla ice cream to add body and thickness.

The starch molecules in cornstarch swell up when heated to provide thickness. Xanthan gum is especially effective at thickening up syrups without adding cornstarch flavor. And ice cream lends creaminess while also thickening the shake.

Shamrock Shake Syrup Recipe

Now that we’ve broken down the key ingredients and techniques, here is a recipe to make a clone of McDonald’s Shamrock Shake syrup at home:


  • 1 cup granulated sugar
  • 1 cup water
  • 2 tbsp cornstarch
  • 1/4 tsp xanthan gum
  • 1-2 drops green food coloring
  • 1 tbsp mint extract
  • 5 fresh mint leaves


  1. Bring the sugar and water to a boil in a small saucepan.
  2. Remove from heat and add the cornstarch and xanthan gum, whisking until fully dissolved.
  3. Add the green food coloring and whisk until evenly colored.
  4. Stir in the mint extract and add fresh mint leaves.
  5. Allow to steep for 30 minutes, then remove mint leaves.
  6. Refrigerate syrup for at least 2 hours before using to allow it to set.
  7. Add 3-4 tbsp of syrup per 8 oz of soft serve ice cream to make your Shamrock Shake.

This easy Shamrock Shake syrup recipe allows you to create the perfect minty green shakes at home. You can even riff on the flavors by using different natural mint teas or extract flavors.

Nutrition Information of Shamrock Shake

While the Shamrock Shake brings the fun flavor of mint for St. Patrick’s Day, it’s still an indulgent, sugary treat. Here is the nutrition information for a small McDonald’s Shamrock Shake:

Nutrition Facts Small Shamrock Shake
Calories 540
Total Fat 11g
Saturated Fat 7g
Trans Fat 0.5g
Cholesterol 55mg
Sodium 180mg
Total Carbohydrates 88g
Dietary Fiber 0g
Sugars 77g
Protein 8g

As you can see, while tasty, the shake is high in sugar and calories and low in nutrition. The amount of sugar is equivalent to around 19 teaspoons! Going with a small size or making your own lighter version can help reduce the sugar content.

Buying Shamrock Shake Syrup

While making your own Shamrock Shake syrup at home allows you to control the ingredients, you can also purchase pre-made syrup to simplify the process:

  • Torani Shamrock Shake Syrup – Popular brand that makes a range of flavor syrups for coffee drinks.
  • Monin Shamrock Shake Syrup – Another reputable syrup brand that distributes to many coffee shops.
  • DIY Shamrock Shake Syrup kits – Some companies sell kits with premixed powder and flavors.
  • Homemade sellers – Check sites like Etsy for people who make and sell the syrup.

When purchasing pre-made syrups, check the ingredients and nutrition labels when possible to know what you’re getting. Syrups from coffee shops or specialty suppliers will use higher quality ingredients.

Shamrock Shake Variations

The classic McDonald’s Shamrock Shake is minty green and made with vanilla soft serve. But over the years, they’ve rolled out some fun variations on their iconic shake:

  • Chocolate Shamrock Shake – Available in select locations in 2019 and 2020, swaps vanilla for chocolate soft serve.
  • Shamrock Chocolate Chip Frappe – A frozen coffee blended with mint and chocolate chip flavors.
  • Oreo Shamrock McFlurry – Vanilla soft serve with Shamrock syrup and Oreo cookies.

You can also get creative with making specialty Shamrock Shakes at home. Try ideas like:

  • Using different mint flavors like peppermint or spearmint.
  • Blending the syrup into frozen yogurt instead of ice cream.
  • Adding chocolate chips, chocolate sauce, or cocoa powder.
  • Swirling in caramel, peanut butter, or other fun sauces.
  • Topping with whipped cream, crushed candy pieces, or mint leaves for garnish.

The possibilities are endless when you make your own Shamrock Shake syrup! Adjust flavors to create the perfect green treat for St. Paddy’s Day.

Storing Homemade Shamrock Shake Syrup

When making your own Shamrock Shake syrup, proper storage is important for safety and maximizing shelf life. Here are some tips:

  • Refrigerate syrup – Keep prepared syrup chilled at all times to inhibit mold growth.
  • Airtight container – Store in a container with an airtight lid to prevent leaks and evaporation.
  • Freeze for long term – For storage up to 3 months, freeze syrup in ice cube trays or muffin tins.
  • Label with date – Mark containers with date syrup was prepared for reference.
  • Sanitize equipment – Clean blender, spoons, funnel etc thoroughly before and after use.

With proper storage techniques, homemade Shamrock Shake syrup can last 2-3 weeks refrigerated or up to 3 months frozen. Be sure to discard any syrup that smells or looks off.

Shamrock Shake Copycats

The unique flavor of a McDonald’s Shamrock Shake is hard to duplicate exactly at home. But some fast food restaurants offer their own versions you can try:

  • Arby’s – Their “Mint Cream Shake” has a peppermint taste.
  • Baskin Robbins – Try their “Mint Chocolate Chip Shake” for a thick, creamy version.
  • Sonic – Their “Mint Master Shake” comes in chocolate too.
  • Chick-fil-A – Seasonally they offer a “Mint Chocolate Chip Milkshake.”
  • Dairy Queen – Blizzard treats like the “Mint Oreo Blizzard” offer a similar taste.

Check your favorite fast food spots to see if they are serving up minty milkshakes. While not exactly McDonald’s, these can satisfy your craving for a refreshing frozen mint treat.


The Shamrock Shake has become a cult favorite among McDonald’s fans for its refreshing vanilla-mint flavor. While the exact recipe is a closely guarded secret, the iconic green color and minty taste comes from a proprietary syrup mixture likely containing natural mint, sugar, corn syrup, food coloring, and stabilizers.

You can create a tasty homemade version with ingredients like fresh mint, matcha powder, peppermint extract, ice cream, and xanthan gum for thickening. Or opt for ready made syrups from brands like Torani and Monin. However you choose to make it, the special Shamrock Shake flavor is perfect for commemorating St. Patrick’s Day and enjoying the wearing of the green.

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