110 g (½ c.) sugar (Any white sugar that easily dissolves in milk)
2 large eggs (Large eggs weigh at least 57 g in their shell, or 50 g without; you want to roughly match the weight of the sugar)
240 mL (1 c.) whole milk (At least 3% butterfat)
240 mL (1 c.) whipping cream (35% butterfat)
1.75 mL (⅓ tsp.) vanilla extract (Yes, it’s hard to measure such small quantities)
100 g (¼ lb.) wild blueberries (I.e., the tiny ones that are only available for a few weeks locally in the summer)
Whisk the sugar thoroughly into the eggs in a medium mixing bowl.
I used to use a hand mixer, but a fork works just as well and is easier
Bring the milk to a simmer in a heavy medium saucepan.
Pour the milk as slowly as you can into the eggs and sugar, stirring
constantly to keep it from cooking the eggs. You now have a custard.
Pour the custard back into the saucepan on low heat and stir constantly
until... this is the tricky part.
If you heat the eggs too much, they will scramble, and you will have to
start over again.
If you don’t heat the eggs at all, and your eggs carried salmonella,
your ice cream will be contaminated.
The standard advice is to heat them until the custard thickens slightly,
which can take a little while.
Alternately, you can use a Thermapen and a food safety chart based on
local guidance about egg safety.
Pour the custard through a strainer
(unless you are very sure you haven’t overcooked it, but why risk it?) into a
large, clean container. While it is cooling slightly, use a spoon to
crush the wild blueberries, then stir the
whipping cream, vanilla, and wild blueberries into the custard.
Cover the container and put it in the fridge until it’s cold;
you can leave it there overnight.
You may be tempted to skip this step; you can, but it will negatively affect the
texture of the final product.
Set up your ice cream maker, then
transfer the container to the coldest part of your coldest freezer,
and leave it there for 30 minutes.
Again, do not skip this step: to get the best texture, you want the custard to
be just barely not frozen when it goes into the machine.
Prefreezing the custard will minimize how long it is exposed to
room temperature, and therefore the formation of large ice crystals.
Process the custard in the ice cream maker until it turns into soft
ice cream. This should take only 10–15 minutes because of the
prefreezing you did.
Transfer the soft ice cream immediately to the coldest part of your
coldest freezer for at least two hours to let it set.
You can leave it in for days instead if it’s more convenient.
Transfer the ice cream to a warmest part of your warmest freezer
to let it soften to a comfortable eating texture.