Just as a forewarning, if you are using a blender and go with Judd's amounts (I personally use the same amounts) some kavas will become really difficult to blend and might need a tad bit more water. I still experience this even with cold water and it doesn't seem to happen for any good reason (different kavas, inconsistently). Could be due to my blender not being a good one (I'd imagine Judd's is high-end) or that I blend on low and it's just not quite enough "ummph" to move the thick stuff around. My poor blender starts to make strange noises and only the stuff at the bottom half of the belnder gets blended.
Also, if you plan on using hot water, definitely use a little bit more water since the hot/boiling water preps always leave a very, very thick blend that makes blending difficult like ^