Originally Posted by bgeek
Then there isn't any diacetyl in your beer. A diacetyl rest isn't a hard rule when brewing and may in fact never be necessary if one pitches the proper amount of healthy yeast and controls the fermentation temperature. You did good.
You might want to take a look at the forced diacetyl test. It will tell you whether you have the diacetyl precursor, which will slowly turn into diacetyl. You may not have any diacetyl now, but it would be good to check that you won't end up getting it later. A diacetyl rest should clean up those precursors, too, keeping you from getting it later. But, don't bother with the diacetyl rest if you don't have any diacetyl or the precursor.
Basically, for the forced test, you heat up a small sample in a closed container, let it cool, and then compare to an unheated sample. The heat causes the precursor to turn to diacetyl, so you would get a buttery smell if you had the precursor.