In version 5.1 of "Genshin Impact", the method to obtain the bitter water recipe is as follows:
Answer: Go to Zhakan Food Stall and talk to NPC Xianka to buy it;
1. Locate the Holy Fire Arena and Chuwen Market on the map, and arrive at the Zakan Food Stall upon arrival.
2. Talk to NPC Xia Anka to confirm the purchase of recipes.
3. On the recipe purchase page, pay 4,500 Mora coins to get the bitter water recipe.
The above is all about how to obtain the bitter water recipe in "Genshin Impact" 5.1. For more game guides, please click the source code website.