For stem hash, the weed stems have to be ground very fine. Choose a mason jar and put the hash stems in it. Cover it with 99% isopropyl alcohol. Cover the mason jar and shake it vigorously for at least a minute or two. Use a cheesecloth to strain all plant material out. Use a wide bottom glass to transfer the liquid to. Keep it in a well-ventilated area until the alcohol evaporates. A sticky substance should be left on the bottom. Scrape it off as best you can and form it into a little ball. It is ready to be used.