Combine all ingredients in a small saucepan over medium-low heat.
Bring the mixture to a boil, then reduce and simmer for 5-10 minutes.
Once the berries begin to break down and the syrup is a deep red color, remove from the heat.
Allow the mixture to cool fully before straining out the solids. Solids can be saved and used as a topping for ice cream or even mixed into overnight oats or chia pudding!
Store the finished blackberry simple syrup in a closed container in the refrigerator for up to 2 weeks.
Notes
How to make fresh berry syrup (no cooking)
One of my favorite DIY syrup hacks is to just muddle fruit or herbs into plain simple syrup instead of having to whip out the pots and pans and start making a mess. This is especially great when you just want a small amount of the syrup, like for one or two drinks.This method is also good when you want to preserve the fresh flavor of the fruit or herb and not alter it with high heat. Cooked blackberries do taste quite different from fresh, ripe berries. To make a no-cook blackberry simple syrup:
Muddle
Add your berries (2 cups) to a jar or other container and muddle them thoroughly to extract their flavorful juices. Be sure that every berry is thoroughly smashed.
Make plain syrup
Next, add your 1 cup sugar (or honey) to a separate container and top it with 1 cup warm water. You can use room temp water, it will just take a little longer for the sugar to dissolve. Stir until you have a clear simple syrup.
Mix it up
Now, combine the simple syrup with the smashed berries and stir to incorporate. It's helpful to do this in a mason jar, screw on the lid, and then give it a good shake.
Strain and store
Lastly, strain the mixture through a fine mesh strainer, being sure to press on the solids to release all of that delicious fresh blackberry flavor. Store your fresh blackberry syrup in a closed container in the refrigerator for up to two weeks.