The precursor to THC is CBD. It is one step away from being THC, but does not get you stoned. The THC is eventually converted to CBN's, which are only one fifth as potent.
The trichomes still tight to the leaf are predominantly CBD's. They elevate on stalks as they become THC, and then turn cloudy yellow as they degrade into CBN's.
Both premature pot and outdoor leaf tend to have a high CBD content, and are worth rearranging the molecular isomers, or "isomerization".
I have a process for oil, but have never even heard of it being done with hash. It is worth thinking about. I won't post the whole process for oil here, but for the sake of a starting point, it involves 1 drop five normal hydrochloric acid per half dram, boiled for 45 minutes. The acid is then neutralized to stop the reaction. Done for too long, and it converts the THC into CBN.
Can we work up a way to do this with hash?
A lower temperature means less reactivity, hence much more acid will be needed. I know sulfuric acid is used sometimes, but hydrochloric was the acid of choice because it is cleaner. This says to me it is likely possible with many different acids.
It might be as simple as soaking the hash in lemon juice or vinegar for a stretch of time, and then rinsing it with water again.
Thoughts?