Well I have never really kept rice long enough to know whether it would go bad or not. Since I do not usually buy rice in bulk (in fact I buy small bags at a time), it is usually used up in about just over a week. However, taking into account all the posts that I have read here, it seems like it is a good idea to wash rice before cooking it, so I will continue to do so. I never knew why I did it, it is just that I have seen it done by my mother over the years, and it just seems to me like the natural thing to do.