本研究係依據 ISO 14046水足跡標準及 H2Oe水足跡評估法，探討濾泡式咖啡（或稱耳掛濾泡式咖啡）進行水足跡評估之必要原則與方法，以獲致水足跡評估結果。 H2Oe水足跡評估法結合了消耗用水與降級用水（即品質退化之水）的潛在環境衝擊，而彙整成一個以生命週期評估為基礎之指標，稱為產品之水足跡。本文以一家實際的咖啡烘焙館為個案，並選擇個案咖啡烘焙館最受歡迎的耶加雪夫咖啡為標的產品，亦即選擇耶加雪夫濾泡式咖啡進行水足跡評估。在系統邊界上是屬於「搖籃到墳墓」模式，其水足跡量化包含該產品生命週期之原料取得、製造、配送銷售、使用、及廢棄處理等階段，功能單位為「一包耶加雪夫濾泡式咖啡（內含十公克咖啡粉）」。本研究結果顯示，個案咖啡烘焙館所生產的耶加雪夫濾泡式咖啡每功能單位之水足跡為 3119.18公升 H2Oe。本文也探討了一個節水情境，該節水情境每功能單位之水足跡為 958.23公升 H2Oe，與基本情境相比，節水情境節省了 69.28%之水足跡。

In this study the standards of ISO 14046 water footprint (WF) and H2Oe water footprint assessment method are used to investigate the required principles and methods to assess WF of drip coffee. Based on the relevant standards, the WF of drip coffee is gained. H2Oe water footprint assessment method involves combining the potential environmental impact from consumptive and degradative water use and integrating into a single LCA-based indicator called product water footprint. A real coffee shop is used as a case study and the most popular coffee type, i.e., Yirgacheffe drip coffee, in the shop is chosen as target product to assess its WF. The system boundary is “cradle to grave” and the WF quantification shall include the life cycle of the products from raw material acquisition through production, distribution, use, and end-of-life treatment, which could include recycling or disposal. The functional unit is “one bag of Yirgacheffe drip coffee (with 10g of coffee powder inside)”. The results of the study show that the WF of drip coffee is 3119.18L H2Oe. Moreover, this study investigates a water-saving scenario which assumes that the packaging of drip coffee is simplified. The results show that the WF of water-saving scenario is 958.23L H2Oe, i.e., reducing 69.28% of water footprint when compared with base scenario.