Saltpeter

Saltpeter is an alchemy ingredient in that is needed to craft the following items:
It can be found as both random and guaranteed loot, received as part of quest rewards, or purchased from the following merchants:
* All alchemists except the Freya Priestess
* All herbalists in White Orchard and Velen
* All herbalists in Skellige except Yolar
* Herbalist outside the Cunny of the Goose inn
* Herbalist in Glory Lane
* Merchant in Putrid Grove
* Otto Bamber at the Herbalist's Hut northeast of Oxenfurt
* Herbalist in Barrengarth 
* Master Topical in his hut northwest of Vikk Watchtower 
* Pinastri in her home northeast of Dun Tynne Crossroads 
2 × saltpeter is always found in a big chest at the Mill in White Orchard, 4-5 more in the big chest near the grindstone at the Nilfgaardian Garrison (soldiers will consider is stealing though), and 10 in the room with the gargoyle during Wandering in the Dark. 4 can be received from Tomira if she is talked to about Claer after completing Contract: Devil by the Well, and 5 for completing Practicum in Advanced Alchemy.
Category:The Witcher 3 ingredients