Sometimes this happens with enhanced kit(+5 kit this time): you make good use of the ingredients and have produced 2 flasks of orkish draught

Not 100% sure I'm reading the above correctly, but I've had both Baker and Antidote double-mix with less than a +5 kit. So chance to double-mix is either present for any enhanced kit, or varies depending on the herblore being mixed. -Belamir

1) Grey Havens herbalist

Price: Power-ring or belt

 Description: A delicate set of translucent glass measuring cups.

2) Niuldor

Complete Niuldor's quest to get upgrade. See under Quests.

 Description: An exquisite retort of polished copper.

3) Blue Mountains weaponsmith

Price: shining mail

 Description: A sharp-edged shining sickle.

4) Scarred man in Sewers

Find his herbal, that was stolen from him. need an 'herbal' which can load randomly on wuda, wyrdda, or some other mobs.

 Description: A handful of small, silvery bottles and vials. 

5) Thrakghash

After he stops talking, ask Thrakghash research. First he will ask for herbs you must gather for him (foxtail, gingseng and 2 random), after that bring him rare herblore. Venom, belladonna doesn't work; antidote, arachnia, and better will. *Must be hero+ level to trigger event.*

 Description: A fine slender paring knife and a stout chopping knife.

6) Grobb (Zaugurz orcs)

 Description: A mortar and pestle of smooth, white marble.

Purple Scroll will yield his upgrade.

7) Sabb

Sabb wears herbal kit with his upgrade on his belt. Kill him to get it. Sabb is Rushak camp in Dunland, east of Wyrdda. Sabb sneaks and the whole camp appears at spring to summer only.

 Description: A round metal sieve with a mesh of golden threads.