I’m not always right at one quart, but usually pretty close. If it looks like your one-quart ice cream maker is about to overflow when you put in the ingredients I call for, just downsize a little.
2) What kind of “milk”? Since this is vegan ice cream, you have a lot of leeway in what you use. You can use soy, rice, almond, hazelnut, oat, coconut, or whatever non-dairy milk you like. If I’m making a coconut ice cream, I always use coconut milk. Otherwise, I generally use a combination of soy milk and soy creamer. The soy creamer adds a some extra fat, which makes richer ice cream. If you want really rich ice cream, use all soy creamer. Or make a coconut ice cream with full-fat coconut milk and swoon with fatty delight. If you want low-fat, go for all soy milk. You could even use reduced fat soy milk if you wanted. Remember, though, the less fat the ice cream has, the less rich it is likely to be. Health vs. taste. Why is life so hard?
3) Arrowroot. Arrowroot is a starch that you can use to thicken sauces, pies, or (in this case) ice cream. You can probably find it in most health food stores in either the baking or spice department. I recommend buying it in the bulk section because it’s probably cheapest that way.
Arrowroot is a tricky ingredient. You must heat it to activate the thickening powers, but if it gets too hot, you kill the magic and you get not thickening. I’ve worked out a way to get this perfect every time, though.
First, mix the arrowroot with about ¼ cup of the milk you’re using. Set this aside. You’ll be heating the rest of the non-dairy and dissolving the sugar into it. Let this liquid come to a boil, then take it off the heat and immediately pour in the arrowroot slurry. Stir it so the mixture gets even distributed. You should feel the thickening effects of the arrowroot almost immediately. It’ll be even more obvious when the liquid cools down (which you have to let it do before you put it into your ice cream maker).
4) Other recipes. I should note that there is an entire book of vegan ice cream recipes called Vice Cream. I haven’t purchased the book because the recipes frequently call for cashew nuts/cashew milk as the liquid base, and I’m allergic to cashews. As much as I love ice cream, I love continuing to live even more.