½ cup of soy milk, plain and preferably unsweetened
1 cup plus 2 tablespoons of canola oil
¼ teaspoon of apple cider vinegar
¼ teaspoon of agave - or you can use honey if you're Orthodox and don't mind exploiting the bees
¾ teaspoon of kosher salt
½ tablespoon of fresh lemon juice
zest from 1/8 of a lemon
1/8 teaspoon of dry mustard
Put everything in the blender and process until it is thick. I make mine in my Vitamix and it takes about 15 seconds. If you have a lower speed blender you may need to process a little longer. The homemade vegan mayonnaise will become thick and completely emulsified exactly like a mayonnaise made with egg.
You will not be able to tell the difference between this and egg mayonnaise. The flavors may be slightly different from your favorite brand, but the texture and overall flavor profile are just like egg mayonnaise.
I have kept this in my refrigerator for a couple of weeks. It will last as long as the soymilk.
If you only have sweetened soy milk wait and add the agave at the end, you will probably need less, but that will vary by brand of soymilk and your taste.