Sieves

Marijuana Horticulture

by Jorge Cervantes

The first time I saw sieved cannabis resin was in 1983 at the Cannabis Castle in Holland. Neville, owner of the Seed Bank, had a large silkscreen stretched across a frame that was set on top f a large desk with a glass top. We would toss a handful or two of buds on the screen and bounce them around a few seconds. After two or three rounds of tossing and bouncing, a thin sheen of resin could be found on the top of the glass below the silkscreen. I had never smoked anything so potent in my life.

Resin heads are different sizes. With the help of sieves, you can use the differences in resin head sizes to separate them from other plant matter. Typically, a minimum of two sieves are used to make hash. The first one filters out the large plant matter and larger debris, letting the resin glands and small debris pass through to the second sieve. The first sieve should have 135-150 micron pores. The second sieve allows small resin glands to pass, while it holds back large, mature resin glands. The pores on the second sieve should be from 50-60 microns. You can find silkscreens at your local hobby and art supply store. Printing supply stores also sell framed screens.

To sieve, plants should be as dry as possible and cold so resin glands break off easily. Be careful not to force the plant material through the sieve. Forcing will break more resin glands and smear their contents on the sieve and and other plant material. The contents of these ruptured glands cannot be recovered.

Normally, the largest mature resin glands fall first. They are followed by less mature glands and debris including pistillate hairs and plant debris. If you abuse sieving and force too much through the sieve, the hash will be green and of ow quality. At best, sieving removes only half of the THC-rich resin in cannabis.

Atmospheric relative humidity can slow the sieving process to a halt because it causes the pores of the sieves to clog. High humidity also remoistens dry plants, thus making it more difficult for resin to fall free.

Make sure the micron size is labeled n sieves. Color coding helps, but there is nothing as good as the micron size of the screen.

Once prepared, break up buds and foliage over a sieve, and tap the sieve lightly to jostle resin heads through the pores. You can also rub the leaves lightly on the sieve, but this will force through more green foliage. Resin powder will sift through the screen. The more resin on the plant material, the more resin that will fall through the sieve. Use a credit card to move the cannabis back and forth across the sieve. Exert minimal pressure on the cannabis to coax the highest quality resin through the sieve. The first layer of powder will be the purest. Sieved hash contains more debris than most other methods, but sieving is a simple and inexpensive method to make hash.

Collect the powder below the sieve. Now the resin powder is ready to press into a piece of hash. Pressing generates a little heat which also helps congeal the resin glands and debris together.