quick question: soy milk powder to water ratio

[ppunkgoddess]

I have some soy milk powder and I'd like to use it for baking (cupcakes) but I don't know the correct ratio to water to make reasonable milk.

can anyone advise?

Also is it going to work for cupcakes, the VCTOTW cupcake recipe calls for soy milk + apple cider vinegar to curdle, will this curdle like regular soy milk? I have regular if I need it but I'd like to use my powder if I can.

Thanks!