Homemade Coconut Milk Icecream (without an icecream maker)

Okay, for those of you that don't know, I am a scientist by trade.  Today I gave a presentation on colligative properties, which actually consist of things we see in our every day lives, but may not think about.  The four properties are: freezing point depression, boiling point elevation, vapor pressure, and osmosis/osmotic pressure.  By adding solvents (like salt, sugar, etc.) to a solute (water, for example) these properties will change for that solution.  This is why putting salt on the icy roads melts it--it changes the freezing point of the water (well, it would actually be salt water now).  And this is also why you need to add salt to your ice when you are making ice cream.  The freezing point of cream (and I'm guessing coconut milk is similar enough) is around 27F, where the freezing point of water is 32F.  It is impossible for ice cubes to freeze the cream to make ice cream., but by adding the salt to the ice, it drops the freezing point down a few degrees creating the optimal freezing conditions. I love science! :)

So, today when I was giving my presentation to my coworkers I had them make their own ice cream--because we do need to fun at work every once in a while. :) This would be really fun to do with your kids or at a birthday party, etc.  You can also make bigger batches, I just have the single serving listed below, so every one can make their own. :) Just be sure you wear your snow gloves or oven mitts, because the ice gets really, really, really cold. :)

Homemade Coconut Milk Icecream

1/2 cup coconut milk (like Thai Kitchen, so the actual real creamy, canned coconut milk), you could use dairy-free milk, but then it would be ice milk, not ice cream--so, not nearly as creamy. :)
1 1/2 T sugar
1/4 t vanilla
optional add-ins: 1 T cocoa or ~3 T pureed fruit (like strawberries...mmmm) If you want to add chunks of stuff (cookie bits, strawberry pieces, etc.), wait until after the ice cream is frozen, then stir in those pieces

For ice cream making:
~1 2/3 cup ice
~1/3 cup salt (if you have rock salt great, if not use whatever salt you have, it doesn't really matter)
1 Ziploc Sandwich Bag
1 Ziploc Gallon size storage bag

Directions
Mix all ice cream ingredients together and pour into the sandwich bag (you could also mix the ingredients in the bag, too).  Remove all excess air from the bag and seal it (make sure it's sealed really well, or you'll have salty ice cream).

Place ice and salt in the one-gallon bag, and add the sealed ice cream bag.  Remove as much excess air from the gallon size bag and seal it.

Knead the bag for 7-10 minutes.  You will want to have gloves on during this because it gets cold.  Make sure, also, that when you are knead that the small bag is in constant contact with the ice, and that it is the small bag you are kneading.  This will keep the ice crystals small and create a very smooth and creamy ice cream.

Remove the ice cream bag and wipe off the salt water from the outside of the bag.  Your ice cream will probably be a little soft, but it will be delicious. You can also freeze it and enjoy it later, the ice cream in the above picture was in the freezer for about an hour and a half before I dug in and indulged. :)  It's my own Neapolitan ice cream. I actually did three 1/2 servings in 3 different sandwich bags, but put them all in one gallon size ice bag, and it worked just fine.

Enjoy your ice cream!