Origin of the Day

The idea for Global Pumpkiln Day emerged during the Halloween season of 2025, when Jan Mumme, a biochar engineer and researcher, shared a LinkedIn post and video about using a pumpkin as a small biochar kiln. The idea originally emerged from a simple intention: to impress his nephews, who are enthusiastic Halloween fans, with a fun STEM lesson.

The post prompted discussion, and Kathleen Draper,  a long-standing contributor to the biochar field, including as Chair of the International Biochar Initiative and an author of biochar books, suggested establishing a shared annual date for others to experiment and participate.

From that exchange, the idea of Global Pumpkiln Day emerged — one date, many places, shared intention.

The original LinkedIn post that sparked the idea can be viewed here.