In a medium saucepan, simmer the berries, sugar, and lemon juice over medium heat until they are bursting and have dissolved, about 5-10 minutes. The longer you boil it the thicker sauce it will be. I recommend trying a bit of sauce after a few minutes to see if it needs more sugar.
Let the mixture cool for a few minutes.
Using a regular or immersion blender, blend the mixture until smooth.
If you like a slightly thicker, more textured sauce you can leave it as is.
Otherwise, strain the coulis using a fine mesh strainer for a super smooth coulis.
If you want a thinner sauce, you can add a bit more lemon juice, water or flavored liquor to thin it out to your desired consistency.
Enjoy on your favorite dessert!
Notes
The amount of sugar needed will vary depending on the sweetness of the berries and personal preference. I recommend starting with two tablespoons and adding more to taste (typically up to 4 tablespoons).
You can substitute honey, agave, maple syrup or brown sugar for granulated sugar.
This recipe makes about a cup of blueberry coulis. It can be doubled or halved as needed.
This sauce will last about a week in an airtight container in the refrigerator.