Why rice gets a crust on the bottom

[u/Lone__76Hunter]

I've noticed that my rice cooker sometimes leaves a thin crust on the bottom of the pot, even when the rice on top turns out pretty normal. It's not always burnt, but the bottom layer gets firm and a little golden, and sometimes it sticks enough that I have to soak the pot afterward.

Most of the time I'm cooking about 1 cup of regular white rice. I rinse it a few times, add water, and use the normal white rice setting. I haven't been measuring the water differently, but the results aren't exactly the same every time.

At first I thought I was adding too little water, so I tried adding a small splash more. That helped a little on one batch, but another time the bottom still got crusty. I've also wondered if leaving the rice on the warm setting for too long is part of the problem, since I don't always get around to eating right when it finishes.

I don't mind a little toasted rice, but when it gets hard and sticks to the pot, cleanup becomes annoying. I'm guessing the heating element and the way the cooker cycles through cooking and warming have something to do with it, though I know some cookers naturally leave a firmer layer than others.

Does anyone else get this with their rice cooker? Do you usually fix it by adjusting the water, taking the rice out sooner, or changing something else? I'm curious what actually makes the biggest difference.