is their more complicated options other then butane extraction?
I think the top end process is considered to be CO2 super-critical extraction. It's orders of magnitude more difficult than butane extraction, but has some advantages such as not extracting the wax and not leaving residue. It's how food grade extracted oils are made from other herbs professionally. Due to the pressure and complexity it's a five figure investment.
A diagram:
It's become a hot discussion since the california appeals court decided last year in the bergen case that chemical solvent extraction methods such as butane or iso-alcohol are illegal (as far as manufacturing) when mechanical separation via sifts, cold water and non-chemical lipids (butter, cooking oil) wouldn't be under prop 215. Some believe the courts wouldn't consider CO2 or steam to be chemical solvents, even though they really are because the law in question was intended to address environmental impact. Nobody has tested it though. A decent amount of co-ops have stopped stocking oil because of this, and a couple have apparently picked up a source for CO2 extracted oil instead. But I haven't seen it in person and knowing the market it's very possible it's bullshit. Probably would take GC to prove a lack of butane residue to know for sure.
Technically I think butane extraction isn't actually super-critical, and other than CO2 and steam there aren't other methods "beyond" butane being used - certainly not "many other" methods at least. Practically people pretty much use sifting, scissor/finger, ice water bags, isopropyl shakes, butane (or similar) and CO2 (theoretically at least). I don't think people are using other methods to any real degree in the US.
It's all kid stuff compared to the Skunkman's secret 99.9% dry sift method though. Never have I seen anything like this, it's crazy. Yield is supposed to be 1g-3g per kilo of bud, ahaha. The pictures are in fucking credible: (warning, makes the best kief you ever make seem totally 3rd rate)
cheers
