Strain the cashews and place them along with the water in a high-speed blender. Blend for 90 seconds.
Add the guar gum and blend in the blender for about 15-20 seconds until the mixture thickens. It should be fairly thick. Check the mixture's temperature. It can get really hot in the blender. Let it cool until it cools to 100℉ or less.
Add this mixture to a bowl, preferably with a spout, and whisk in 1 sachet of Yogurt Plus starter culture. This distributes the good bacteria throughout the milk.
Place the milk in yogurt jar or jars without lids and incubate in your yogurt maker for 8-12 hours. The longer you let it ferment the more tart and sour it will taste. It likes the consistent, lukewarm temperature of 110°F. This is paradise for all the good bacteria and promotes their growth.
Remove the jars from the yogurt maker, place lids on the jars, and then place the jars in the fridge to cool and set for at least a couple of hours. As the yogurt cools, it will get even thicker! Store in the fridge.