I doubt he would dilvulge any info about his process. Id be very surprised otherwise.
First of all, freeze drying and dehydrating is 2 very different things. I have had my kava freeze dried before and I have had some freeze dried kava from another company that had made some. To me it was weaker than any kava I sell, both the one I had made with my kava and the other made from some other kava. The taste was very mild and it mixes with water and dissolves instantly with no powdery residue at the bottom. The reason being is that the people who do the freeze drying told me that they can not freeze dry the powder, they only freeze dry the liquid from the prepared drink, not the powder at the bottom of the glass. I think this is why it was so weak. The guy that did mine for me also tried to do the powder at my request and it was not the same. It was gritty, even though this was not micronized and medium grind was used to make the drink.
For a product that dissolves in water like that instant coffee then freeze drying works but the potency is not as much as the regular drink you make with the powder but there is no grit or powder.
The product with the powder freeze dried as well, it just did not make sense to me because of the cost and the fact that it ended up being like my micronized kava.
I use special dry boxes that uses the sun,not direct sun, these boxes are just over 2 stories high and can dry a large amount of product, and I am able to control the temp to ensure that it dries slowly with very low heat.
Heat will change the flavor and direct sunlight will affect the potency. This is very efficient and the Noni growers over here use the same style as I do because Noni can not take the heat either, it also needs to be dried slowly.
I hope this helps, let me know if you have any questions, aloha.
Chris