yes, i also puzzle why i can't produce nice bean sprouts. it has
something to do with temperature (20-25C), water
(non-chlorinated) and quality of beans. at least that's how the
theory goes.
i have more success with mung bean sprouts. soy beans are
hopeless for me. i also use a kettle and it takes about a week
to 'harvest' mung bean sprouts. they look nothing like
miracle-gro fed plants but quite decent.
good luck.