You're right, I don't know who started that rumor about heat "destroying the kavalactones" but it's false. The amount of heat that one would need to destroy the kavalactones would be far higher than anyone would see from boiling water or any normal situation.
From an older thread I posted some info on that for anyone that hasn't seen it....
I found this quote on the old forum:
"About three years ago, a test (using HPLC) was done on boiling the kava beverage (~212F). Loss after a few minutes at that temperature was considered insignificant. Less than 5% of the kavalactones were lost."
[The link is broken, but the quote was from the owner of Hawaiiankava.com]
And:
"This one's more about special lab equipment based extraction so I can't be sure it applies here, but the graph on page 190 (and following pages) shows that, in general, the percentage of extraction increases as temperature increases. Yangonin extraction is essentially 0% until you reach boiling point"
[link seems broken to me, but you could try it:
http://144.206.159.178/ft/553/42507/769267.pdf]
And:
"Various authors have suggested that the two compounds isolated by Cuzent and Gobley, kavahine and methysticin, are the same and correspond to methysticin as it is known today (see figure 3.1). However, the percentage analysis of carbon (C), hydrogen (H), and oxygen (0) given by Cuzent (1861a) for kavahine 5.85% C, 5.64% H, and 28.51% 0) is closer to the composition of didromethysticin (65.21 % C, 5.84% H, 28.95 % 0) than to that of methysticin 5.69% C, 5.15% H, 29.17% 0, calculated in Lebot and Cabalion 1986).
The melting point of kavahine, 120-130 C, is also nearer to that of dihyromethysticin (116-118 °C, Winzheimer 1908; 117-118 °C, Borsche and Bodenstein 1929; 118 °C, Joessang and Molho 1970) than to that of methysticin 132-135 °C, Sauer and Haensel 1967; 136-137 °C, Rasmussen et al. 1979; 139-140 °C, Borsche and Peitzsch 1929a; see also Duve 1981). The differences bserved between these figures would be easy to explain if Cuzent had actually obtained and analyzed pure syncrystals, but the 10 °C variation in the melting point of his kavahine indicates that the substance he analyzed was contaminated. Our best guess is that Cuzent's kavahine was a mixture of dihydromethysticin and methysticin."
[
http://www.aldbot.com/New_Folder-1/ch3lebot.htm]
And (more regarding chemical structure and implications for storage):
"According to Duve and Prasad (1983), there are trends in the deterioration of the major active constituents in both dry powdered root and basal stems. Storage of the samples in screw-capped glass bottles at room temperature resulted in 26, 33 and 55% degradation of the major constituents in the roots and 24, 50 and 48% degradation in basal stems after 22, 36 and 39 months of storage, respectively. Moisture and
temperature are probably the major environmental factors affecting the deterioration of dry powdered plant material. Stability of the active constituents appeared to be dependent on the chemical structure, with dihydrokavain being the least stable and methysticin the most stable (Duve and Prasad, 1983). In addition, stability improves with increasing melting point and the degree of unsaturation. These findings suggest that more polar substances are likely to be stable at room temperature. In contrast, in non-polar molecules like dihydrokavain, the pyrone ring tends to open up to form more polar acidic components which would be readily stabilized by moisture from the storage environment. The identity of the degradation products have not been established but formation of a characteristic off-odor from the samples has been described (Duve and Prasad, 1983), which probably reflects formation of the corresponding acids from the active constituents. Further studies are, however, needed before firm recommendations can be made on storage conditions for powdered kava."
& pretty much dialled out for about a week after. It really made me crook with every precise symptom of Hepatotoxicity. You can never be sure however if I was correct in what I had then I clearly see the issues with it.
