In the jar of a blender or food processor, combine 1 cup whole milk and 5 oz or 150g chopped milk chocolate bar. Blend until the chocolate bar is pretty well pulverized.
Add 1/2 cup granulated sugar, 1/4 cup dutch process cocoa powder, 5 large egg yolks, pinch fine salt, 2 tablespoons 80 proof rum, and 2 cups heavy cream to the jar of the blender, then blend again until just combined. This mixture will not be completely smooth, and that's ok. Avoid over-blending.
Pour the ice cream base into clean mason jars. Fill only until the base of the threads.
Wipe the rims with a clean cloth if any ice cream has dripped, then close the jars finger tight. Set the jars aside.
Fill the sous vide water bath with hot tap water, then slowly lower the jars into the water bath.
Set the sous vide to 175f and allow it to preheat with the ice cream base in the water bath.
Cook the ice cream base at 175f for 1 hour.
Once cooked, use a jar lifter to carefully lift the jars out of the water bath. Place them on a wire mesh rack or hot pot holder on the counter for 30-60 minutes, until slightly warmer than room temperature.
At this point, you can speed up the cooling process, or you can pop the jars in the fridge until later (24-72 hours). If you want to make ice cream immediately, place the jars in a sink and slowly fill with lukewarm water. Once the jars are in the water, add a few handfuls of ice to the water bath. Monitor the ice bath, adding ice as required until the jars are well chilled. If you want to make ice cream at another time, place the room temperature jars into the fridge and chill the mixture until ready to use. Use your base within 3 days.
When ready to make ice cream, operate the ice cream maker based on your ice cream manufacturer's directions.
Serve the soft, freshly made ice cream immediately, or transfer to an airtight freezer container and serve once hardened, in 2-3 hours.
Notes
no ice cream maker?
There are many ways to make ice cream no-churn, here are the two that I feel work best.
Transfer the chilled custard to a freezer ziplock bag. Freeze the ice cream flat until completely solid. Then break it into small chunks and process it in your food processor until completely smooth.
Pour the chilled custard into a large mixing bowl. Place the bowl in your freezer, and every 30 minutes, remove the ice cream and stir vigorously until the ice cream is completely frozen.
Batch:
This sous vide chocolate ice cream recipe makes just over 1 liter of fresh, delicious ice cream!It can easily be doubled, but your ice cream bowl will likely need to be refrozen for about 2-3 hours in between churning each batch.
Storage:
To store your ice cream, transfer the churned ice cream to an airtight freezer container and store it in the freezer for up to 3 weeks.
variations + substitutions
Let your mind wander here! Anything that you love to combine with chocolate can pretty much get thrown into this ice cream!
Rocky Road Ice Cream: fold in some coarsely chopped nuts and mini marshmallows!
Heavenly Hash: fold in marshmallow creme, finely chopped nuts, and more chopped chocolate!
S'mores Ice Cream: fold in mini marshmallows, graham cracker crumbles, and chocolate chips.
Mexican Chocolate: while blending, add in 1/2 tablespoon cinnamon, a pinch of cayenne, and a pinch of espresso powder.