In a medium saucepan, combine the fresh blueberries, 1/4 cup of sugar, and lemon juice. Cook over medium heat for about 5-7 minutes, stirring occasionally, until the blueberries start to break down and release their juices.

Remove from heat and let the mixture cool slightly. Then, transfer it to a blender and blend until smooth. If you prefer some texture, you can blend only half and leave the rest whole.

Set aside the blueberry puree to cool completely.

In a mixing bowl, whisk together the heavy cream, whole milk, 1/2 cup of sugar, vanilla extract, and a pinch of salt until the sugar is dissolved. This will create a creamy base for your ice cream.

Once the blueberry mixture is completely cool, fold it into the ice cream base using a spatula. Mix gently to combine, but be careful not to overmix; you want to see swirls of blueberry throughout.

Cover the mixture and refrigerate for at least 2 hours, or until thoroughly chilled. This step is crucial as it helps the ice cream churn better and results in a creamier texture.

Once chilled, pour the mixture into your ice cream maker and churn according to the manufacturer's instructions, usually about 20-25 minutes, until it reaches a soft-serve consistency.

Transfer the churned ice cream to an airtight container. Smooth the top with a spatula and press a piece of parchment paper directly onto the surface to prevent ice crystals from forming.

Freeze for at least 4 hours, or until firm. This will allow the ice cream to set properly and develop a scoopable texture.