Thageini Wet Mill is one of four mills operated by the Aguthi Farmer's Co-operative Society in Nyeri County. Located at 1,650-1,800 metres above sea level, it receives coffee from around 450 member producers, including approximately 350 men and 100 women, making it the society's second-largest mill. Across its wider membership of around 2,000 producers, Aguthi provides practical training in farm management, harvesting, sorting and agronomy, alongside workshops where members can learn from one another.

Project Origin began working with the cooperative in 2017. Following the quality of Thageini's Washed coffees in 2018, the partnership expanded into station infrastructure and processing education. Carbonic Maceration equipment was introduced in 2019, alongside newly funded drying beds to support more controlled processing and continued quality improvement.

For the Simba lot, SL28 and SL34 cherries are hand-sorted at delivery to achieve a ripeness rate above 90%. They are wrapped in cocoons on raised beds for four days of aerobic fermentation, then uncovered, spread and regularly turned. Drying typically takes 25-30 days until the coffee reaches 10-12% moisture. It is then stored in dried cherry pods at the dry mill until milling and export. Project Origin cups and curates the final lot with Thageini as part of its Signature Supernatural profile.