Pour pinto beans into the bottom of a big saucepan or soup pot. Add water, bacon, jalapenos, cilantro, and garlic and bring to a simmer, about 10 minutes. Pour in 1 can light beer when beans are warmed.
Simmer beans, stirring every couple of minutes, until bacon has completely cooked down and beans begin to break, 3 to 6 hours total. Pour in remaining beer as needed when liquid has evaporated and beans aren't completely covered, roughly every 2 hours. Cover and keep warm until serving.
