Stop cooking your watermelon syrup! I’m here to tell you I have an easy, hands-off way to get the flavor of fresh watermelon into an infused fruit simple syrup that is bursting with the same juices you find in each bite of that perfect summer watermelon. If there is one thing you take away from my entire site about summer cocktails it’s this: stop cooking your summer fruit syrups.
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Why Cooked Watermelon is Yucky
Have you ever had cooked watermelon in anything? No? Me neither, and there’s a reason. It tastes NOTHING like fresh watermelon. The flavor is muddied – not fresh and bright, and it tastes like watermelon flavoring. If you’ve had a watermelon-flavored candy, you know that flavor is nothing like true watermelon’s taste. And it’s awful, nothing I want in my drink.
The normal way to create a fruit simple syrup involves heat. Fruit and water are combined over low heat with sugar, simmered for a bit, then cooled and strained. It’s great for some fruits, like blackberries, lemons, limes, rhubarb, and apples. But for fruits that burst when fresh like strawberries, peaches, and melons, creating the simple syrup without cooking is the best way to preserve that fresh flavor.
How to Make Cold Process Homemade Watermelon Syrup
When I started to work with fruit-infused simple syrups I was disappointed in the strawberry and watermelon syrup recipes I found. All of them tasted like cooked fruit because I was, in fact, cooking the syrup as I made it.
But then I thought about the sugared strawberries my grandma would serve with whipped topping. In the morning, she would slice up strawberries and pour a cup of sugar on them. She’d let it rest until dinner. When she pulled it out the strawberries were swimming in a fresh strawberry syrup that kept the flavor of fresh berries.
So I tried her method and realized that adding sugar to most fruits causes the expression of juice from them. Behind the scenes, sugar is hygroscopic – which means when put in contact with something it attracts water. Sprinkling sugar on fruit pulls the water out of the cells in the fruit, and once that juice is in the jar or bag, it creates a simple syrup.
Because this process is done without cooking, the heat doesn’t alter the flavor of the compounds that make up the aroma and taste of the fresh fruit, leaving you with a syrup very close in flavor to fresh fruit.
The general process for a watermelon syrup recipe is the same as any other fruit. At home, I add 1 lb of fresh, cut fruit or berries to a zippered plastic bag or glass jar. I sprinkle 8 oz of sugar on top and muddle lightly to break down the fruit. Then I put it in the fridge overnight or for 24 hours.
When you remove it from the fridge, it will be a bright, vibrant color, and most of the juice will be clear. I mix it up a bit to finish dissolving the sugar, then use a metal sieve to strain out the syrup. I put the syrup in clean glass jar and store it in the fridge.
The resulting syrup is tastes bright and vibrant and preserves that fresh taste you get from a perfectly ripe berry or fruit.
How Long Does Fruit Simple Syrup Last
Because we’re not cooking the fruit-infused simple syrup, it will last about 10 days, but see below for a tip to extend that time into the 2 to 4-week duration. If the syrups develop mold on the surface, the lip or the lid of the jar, it’s time to make a new batch. Melon syrups will settle at the bottom of the container, so don’t think there’s a problem if your syrup gets a little cloudy as you agitate it.
You can also freeze the simple syrup if you make a large batch. If the sugar to juice ratio is closer to 1:1 it will likely freeze solid, but closer to 2:1 and you can use it immediately from the freezer.
Tips and Tricks for this Watermelon Syrup Recipe
Here are a couple of simple tips to make your homemade watermelon syrup easier and more delicious:
- Use only ripe watermelons. Don’t use over-ripe melons or melons with cracks in them. To pick a ripe watermelon, tap it. Those that are heavy for their size and sound hollow inside are ripe and ready to eat. For more info on picking a ripe watermelon, head here: https://www.watermelon.org/watermelon-101/facts-faqs/
- Seedless watermelons work best here. While watermelon seeds aren’t harmful here, if any of them are cut or broken during the muddling process they’ll make the syrup taste just a tiny bit herbal or vegetal. Not a lot, just a small bit. Since you’ll be using it in small amounts it won’t make a big difference in the flavor profile of your cocktail, but it’s something to be aware of.
- Add vodka to the simple syrup to help it last longer. Because it isn’t cooked, cold-process fruit simple syrups don’t last as long. Sometimes as short as 10 days. Adding a bit of vodka helps them stay fresh and potent. I usually add ¾ oz to a 12-16 oz batch of simple syrup.
- Alter the ratio of sugar to fruit as needed. I generally start with 1 lb fruit to 8 oz sugar. I tweak the amount of sugar-based on the sweetness of the fruit and how much juice it expresses. Taste-testing is your best friend.
- Change the sugar you use. You can use brown sugar, raw sugar, cane sugar, and more. You can even muddle the fruit in honey, maple syrup, or agave nectar for the same effect.
Other Watermelon Cocktails You Might Enjoy
- Watermelon Whiskey Sour
- Watermelon Mint Julep
- Watermelon Mojito
- Watermelon Gimlet
- Tequila Watermelon Mule
- Peach Raspberry Bourbon Sour
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No-Cook Watermelon Simple Syrup – The BEST watermelon syrup recipe for cocktails
- metal sieve
- measuring cup
- glass jar
- 16 oz fresh, cubed watermelon
- 8 oz sugar
- ½ oz vodka optional – it keeps the syrup fresh much longer
- Combine watermelon and sugar in a jar or a zippered plastic bag.
- Muddle them together a bit and put the bag or jar in the fridge.
- After 12 to 24 hours, stir up the contents until all the sugar is dissolved.
- Strain through a metal sieve.
- Store the watermelon syrup in a clean glass jar in the fridge.
- Optional: add ½ oz vodka to the simple syrup to help it last as long as 4 weeks.