The vinegar smell is a result of ACETIC ACID impurities. When dopes been heavily purified, it wont have any vinegar smell.
If it has a vinegar smell, its half-assed heroin. Meaning they didint bother purifying it to no ends. Most heroin will have a vinegar smell because the producers dont care about getting it anywhere beyond the 90% mark of purity. What do you think the other 10% is?? Ill guarantee some of it is acetic acid unreacted and uncleaned from the final product. If youve ever smelt acetic acid youd know what im saying. That stuff reaks to high heaven and beyond, you open a bottle of acetic acid and aliens on mars can smell that shit.
Any other smells are the results of the millions of possible cuts they could be using in street grade dope.
TRULY pure dope, will have no odor detectable by a humans nose (now dogs, thats a different story). It STINKS of vinegar when first made. After youve purified it numerous times over, the smell will be gone.
If your dope dont smell, thats a GOOD sign, means the person actually put effort into purifying it, and then cut it with odorless cuts to boot. Injecting acetic acid impurities is just disgusting. Heroin can have MANY possible smells, based on the cuts used. But if its pure dope, it wont smell. If its your average 'pure' dope (90% SEA #4 for example, the stuff you get in the 700 gram unit bricks) will smell like vinegar, because they never go beyond the 90% mark, the amount of effort it takes to get beyond that % of purity is alot of work and not worth it to the "big boys". Most dope should smell like vinegar. But just because it doesnt, doesnt mean its fake dope. Just means its well made dope.