I happened upon some research that suggested that arsenic levels in rice can be pretty high. One way to reduce those levels is to soak the rice overnight and drain the water. Then cook with a 5:1 ratio of water to rice for 15 minutes, and then pour off the extra liquid. Hah.
BonAppetit calls for 2:1 for long grain, with 2.5:1 for brown rice. In fact, they say "If you don't add enough water, the rice will be underdone and likely burn on the bottom before it's done gently steaming. If you add too much water, the rice will be sodden, mushy, and overcooked."
Now, it is VERY interesting that the water:rice ratios for rice cookers are quite different than for stovetop or slow cookers. I had never researched this before, and I don't use a rice cooker, but I'm seeing 1.5:1 or 1:1 as noted. So I'm baffled. How does a rice cooker work so differently than a stovetop or slow cooker? I mean, it's just all about heat, no? I KNOW how to make great long grained rice on the stovetop, and the ratio is 2:1. Period.
I believe it also has to do with evaporation, so the longer you cook, the more water you have to allow to be evaporated. That doesn't make perfect sense, because stovetop rice cooks very fast, and there can be little evaporation. As a result, you shouldn't need extra water.
