About 4 years ago, when we were looking into having 30% extract produced for us, we searched absolutely everywhere for a company that produced a yellow kava extract that was desirable. I have chromatographs on over 20 chinese manufacturer's 30% kavalactone extracts. To this day, every single one of them come back as Tudei chemotypes. Not a single one that I have ever tested comes back with a favorable, high kavain, low DHK/DHM content, not one. This was unacceptable. Through extensive trial and error, we contracted a domestic company to produce an excellent 30% material from us using high quality Vanuatu borogu root (25% Laterals) that has an excellent 426 chemotype which is retained through the extraction process.
The following is the typical chemotype of the commercially available, ethanolic 30% Extract available on Alibaba
Typical Chinese 30% Extract Via HPLC
Dihydrokavain: 7.618
Dihydromethysticin: 7.395
Kavain: 4.526
Desmethoxyyangonin: 3.987
Yangonin: 3.975
Methysticin: 2.951
Total Lactones: 30.411
Chemotype: 254136
ROH Polynesian Gold™ 30% Extract Via HPLC
Kawain HPLC 8.30%
Methysticin HPLC 6.52%
Yangonin HPLC 6.27%
Dihydrokawain HPLC 5.84%
Desmethoxyyangonin HPLC 3.18%
Dihydromethysticin HPLC 2.92%
Total Kavalactones HPLC 33.03%
Chemotype: 463215
As to the color, it should be yellow. If its brown, well we see what color noble versus non noble kava turns a solvent. Brown extract is also indicative that the starting material is the above ground portions. Variations between bathes on the yellow extracts have to do with varying lactone and lipid contents of the root. Sometimes you get really sappy roots that darken the yellow. Most often the color has to do with the bulk density of the extract (how much maltodexterin cut is used to bring the lactone content down to 30%).
I know of no one commercially producing a C02 based powdered extract due to patents held by the pierce brothers. Not to mention the cost. Its all alcohol based.