Good afternoon, I have smoked riverstone 25g since it came onto the market, I have always smoked a rum flavoured tobacco and have got lots of friends now smoking the riverstone also after I told them how good the product is, lately I have noticed a small dark putty type substance inside each pouch, first there was only a small amount and as weeks have gone buy some pouches have had up to 4grams of this stuff per pouch which overall adds up to quite a bit when im smoking two and a half 25g pouches a week. I buy my smokes in at our local woolworths located at woodford 4514, queensland, australia, thanks craig mckay, 40 bleakley rd, delaneys creek 4514, or [protected]@bigpond.com