Almost any non-dairy milk can be condensed with this recipe. Making vegan condensed non-dairy milk involves adding sugar and reducing it to about half it's original volume. This can take several hours and can be inconvenient if you need it for a recipe. In this case be sure to make this beforehand and store it in the fridge so you have it handy on bake day. The effort is well worth it, especially if you're making Chocolate Coconut Magic Bars or Dulce de Leche.
Condensing any milk results in exposing it to heat so the water evaporates off and the sugars slighly caramelize. If the milk contains protein as with soy milk, the proteins will toast slightly which will result in additional depth of flavor. This is why I recommend using soy milk for best results. Many non-dairy milks such as almond, oat, rice and flax don't contain enough solids to contribute to rich, velvety texture and smooth flavor. If you prefer to use a nut milk, I recommend making it yourself and making sure it's extra thick.
2 ¾ cups (650 mL) non-dairy milk
½ cup (52 grams) sugar
1/8 teaspoon (.75 grams) salt
½ teaspoon (1.5 mL) vanilla extract
Place the non-dairy milk, sugar and salt in a saucepan and cook over a medium-low heat, while whisking frequently. Do this until the volume is reduced to 1 cup which should take about a couple hours. Don't let the mixture boil aggressively- a very mild boil is ok. Keep in mind that you'll have to reduce heat as the mixture gets reduced so you don't burn it. Have a measuring cup handy so you can measure the mixture as you go along. When 1 cup of mixture remains, whisk in the vanilla extract.
Transfer the condensed non-dairy milk to a container, cover and place it in the refrigerator for several hours until it cools to at least room temperature. This will ensure that your condensed milk is the proper thickness for most uses.
Alternatively, you can use a slow cooker to condense the non-dairy milk. Just set it to high, leave the top off and cook for about 7 hours. Don't worry if you reduce the mixture a little too far. Just place it in a food processor with enough water to bring it back up to 1 cup and process it to combine. Store in a covered container in the refrigerator for up to 2 weeks. Makes about 1 cup (237 mL) of Vegan Condensed Soy, Rice, Nut or Coconut Non-Dairy Milk.