Having just read some of the incredible misinformation that has been posted in this node shell, I have been motivated to prepare for the open-minded Everything 2 community the definitive write-up on hashish. As I'm sure many of you know, language barriers and drug cultures have modified how Westerners understand certain terms; I am accounting for these modifications to the best of my ability. Please contact me if I don't get the job done, and I'll edit my post right away!
What is Hashish?
Hashish is the informal Arabic term for the cannabis herb -- "grass". In the Mediterranean region, and particularly in the Fertile Crescent of the Arabic-speaking Middle East, this herb is processed for consumption by concentrating the trichomes of its leaves and buds by removing them from the plant, and compacting them with the application of heat and pressure. Hashish is believed to have first been manufactured thousands of years ago by central Asian hemp farmers who discovered the psychoactive properties of cannabis whilst reaping it, the plant resin (trichomes) rubbing off onto their hands, and amassing by the gesticulations of field labor. After its invention, the manual method of making hashish by thumbing the cannabis leaf spread south and west, and its product became understood as simply the only narcotic generation of cannabis (In America, there is a general belief that marijuana is the most essential form of prepared cannabis -- and of course, this is entirely untrue. Those who cure marijuana know how particular curing is, and drying the cannabis leaf in a controlled manner is actually much more difficult than making hashish).
So I Live in the New World...
If you live across a pond from Eurasia, you may not be aware of the... advantages?.. of smoking hashish over marijuana. I mean, Hell, in the States, weed is very, very cheap (much cheaper than hash), very, very abundant -- like, you-can-get-it-on-any-street-corner-abundant -- virtually everyone is very comfortable with its use and effects, and to top it all off, it gets you high. Some varieties get you very, very high. And I'm sure that all the same is so in Canada, and Mexico, and Brazil... Probably even in Australia. But trust me -- hashish has its place.
The best thing about hashish is that it's easy to move. If you have a nickel-bag of marijuana on you when you're pat down on a pull-over, you're positively done. You've been caught transporting a controlled substance, and the penalties are serious. But in the same situation, with enough hashish to blaze eight people -- lets say a finger of hashish (a finger is usually substantially less than a single gram), you could have it at the bottom of your wallet wrapped in cellophane, where it is invisible to all; the cops could literally search your wallet, and flip right over the thing. That's handy.
Another of the pros for hashish has been well addressed by its noders: Hashish is more intense than marijuana. It is often so intense, in fact, that many people break it up and cut it with tobacco rather than smoking it straight. The high that one gets from hashish should be of precisely the same nature as with marijuana, as their active ingredients are identical; tetrahydrocannabinol, along with between 25 and 75 other cannabinols, depending on the strain, are exclusively common to both drugs. However, it should be noted that American marijuana is usually of the sativa sort, while most hashish is made with the trichome-rich indica sort. Cannabis sativa induces laughter, goofiness and hunger; Cannabis indica induces hypnagogia and pre-dawn philosophizing. The differences are in those fifty or so secondary cannabinols.
The last hash-benefit on which I'll write (although there are probably some that others recognize that I have failed to -- message me if you're one of those "others"!) is that hashish is much more versatile than marijuana. It can be smoked alone, with a pipe or without, or rolled with tobacco into a joint; it can be eaten; and it can be part of a tincture, or further refined into an almost-impossibly-potent hashish oil. While the smoking business is pretty straight-forward, eating hash should be expounded upon a bit. Eating hashish is much better than eating marijuana, for a number of reasons. For one, you don't need to eat nearly as much; for every ten grams of marijuana you would need to eat, one gram of good hashish would suffice. For another reason, hashish potency is much more consistent than marijuana potency. Many people avoid cannabis ingestion because eating weed is flimsy; you never know when the high will hit. Sometimes it hits you like a brick wall, others it takes hours of increasing pleasure to fully kick in. Hash isn't like that. It usually hits hard, after (without having eaten for the last few hours) about two hours. That's that. Also, on the topic of hash oil... Well, that's usually ingested, but it can be added to just about anything -- brownies, cheese dip -- it could even be tossed into a salad in a vinaigrette. And, as I mentioned before, it's ridiculously strong. Lemme tell you, there is no marijuana equivalent to hash oil!
Alright, I'll Bite. How Do I Know Which Hash To Buy?
There are only a few things to know about hashish quality assessment. First, regarding color: There are a number of different colors that high-quality hashish can have. Yellow, brown, red, orange, purple, black... All fair game. What you have to watch out for it green. Green hashish is green because it has leafy matter in it, which is among the last things you want in there. The less green, the purer the hashish, and the stronger the high. Now, regarding texture: Good hashish is pliable, either immediately, or with the application of a little heat. It can be rolled into a finger, broken up with little trouble, and cut without much of a mess. Good hash will turn to bad hash by drying out, therefore losing its pliability; this physical plasticity is a property of all worth-while hashish.
Also: Beware hashish which is cut with materials such as pepper or bay leaf. Most hashish in the United States is impure, due to the fact that it is so expensive to make in a world of marijuana infrastructure. I recommend buying only from very trusted sources, or making the hash you use yourself.
OK, So How DO I Make Hash Myself?
I'll neeeeeeeeeveer tell!
In all honesty, there are so many ways to do it that it isn't worth my address. Basically, get the trichomes off the cannabis plant, put 'em all together, and you've got hash. I make it myself, and I do it with a golden coffee filter, cellophane, paper towel, a convection oven and a heated filament; some use a water separation method, some high-tech tumblers. Go to YouTube, search "how 2 make hashish", and you'll get some decent processes. That's all I can type on that matter...
Personal experience and assorted readings, mostly from long ago. Sorry, Google it if you don't believe what I'm typing!