Black tar heroin smells like vinegar although sometimes the heroin needs to be burned to release the odor. Black tar heroin is a purified form of opium and is so-named because of the sticky, tar-like consistency of the drug.
Black tar heroin is potent and dangerous as it contains a large amount of morphine. Black tar opium is less potent than the heroin form and smells similar to incense. One small pinpoint amount of black tar heroin contains the same amount of morphine as a small handful of black tar opium. Users smoke black tar to achieve a "high" that lasts from 30 minutes to an hour.