This presentation explores the use of plants in the preparation of fermentation starters, such as Japanese koji and analogous starters found across Asia. Fermentation starters are essential for initiating microbial activity in the production of diverse foods and beverages. Across Asia, these starters—typically made from rice, grains, and other ingredients—play key roles in making foods, condiments, and drinks. Regional variants include qū in Chinese, look paeng in Thai, (mae) dombae or mae sra in Khmer, and ragi in Indonesian traditions. While rice or other grains form the primary substrate, various plants are also incorporated. These plants can possibly inhibit spoilage, improve flavour and aroma, and support the growth of desirable microorganisms. Beyond their practical benefits, starter preparation often carries ritual or symbolic significance, with plants serving as both functional and cultural components. Recent trends demonstrate a decline in the preparation of homemade starters, largely replaced by commercial starters. This tendency is especially pronounced in the context of alcoholic beverage production, where legal regulations and social sensitivities surrounding home fermentation impose further constraints. These developments highlight the importance of rigorous study, documentation, and comparison of traditional fermentation starter cultures and their associated plant uses as integral elements of Asia’s culinary and ethnobotanical heritage. Drawing on a comprehensive review of existing literature and fieldwork conducted across the region, this presentation examines the multifaceted roles of plants in fermentation starter preparation, emphasizing their contributions to both the science and culture of fermented foods.