FYI. Almond milk has a low caloric content. (The dairy section Silk Unsweetened Almond Milk IS delicious!) It is nothing like coconut milk in terms of nutrition or consistency…or flavor. (I would be interested in powdered coconut milk though!)
You can buy NOW brand powdered soy milk on Amazon.com… http://www.amazon.com/Now-Foods-Instant-Powder-20-Ounce/dp/B003J4M8HW/ref=sr_1_15?ie=UTF8&qid=1340782593&sr=8-15&keywords=powdered+soy It is unsweetened. I have used it quite a bit. It makes pretty good hot chocolate. (I use Green and Black's chocolate powder…it's vegan.) I usually add a bit of instant coffee to this. I package this up as large single servings in snack size zip locks. Next time, I may add a bit of chili pepper. When adding hot water, I add just a little at first and stir it VERY well; then I add the rest of the water…less clumps. NOW works well in porridge too. I premix my porridge — various quick cooking grains, dried fruit, nuts, powdered soy etc in individual packets.
Beware of Better Than Milk brand "soy beverage"…it is full of synthetic crap and tastes terrible.
(I refuse to own a dehydrator!)