I've been using this method for a while. I actually just made 10 cakes last night, but my ratio's are slightly different, but always come out to the perfect amount to fill the jars. I use a 2:1:1 ratio in cups of vermiculite:water:brown rice flour. I also mix the verm and water thoroughly before adding the brown rice flower, it makes the mixing time considerably less and the consistency fluffier, quicker. but overall great tek. this is a very simple guide to use. I too use sporeworks for spores. theyre great and shipping is quick. also they have quite the selection, and the grab bag is a killer deal.
take it easy