I've got this too. It's happening at public grills. Random Sims just taking turns to make it and then leaving them on the ground. At the Sand Bar they are all over the bar deck and there are people forming a little queue to use the grill to make more. They make one jar, put it on the floor then the next person after them does the same thing.
I've never seen this happen before at a public lot but did see it at a Sims house too while visiting a family I'd created who didn't have the herbalism skill.
Edit: So this is now officially doing my nut in. All guests to the house go straight to the grill and start making this. Even in my Sims home I can't do anything with them except drink them and/or put them in the fridge with "put away". Either that or go into build mode and delete all the jars all over the back yard. Guests stop conversations to do it and it's Sims that don't have the skill so they are all poor quality which makes the drinker unwell.
I just threw a birthday party and all the guests wanted to do was take turns making it on the grill until the grill was absolutely minging and the hostess had to keep cleaning it as the guests complained about it. So...not a great party!
