So obviously this item is inexpensive, but the "wood" definitely turned out to be of even lower, flimisier quality than I expected. Given the price of the item, this was not terribly shocking. My grievance is that this item did not come with assembly instructions. As it seemed simple enough to construct, I did the best I could in putting it together. I thought I had done a proper job until I started putting the bottles on the rack. Apparently, the rungs have different sized holes on them -- one side should have the bottle neck, the other the base of the bottle. I had not noticed that the rungs were not all the same and therefore they are not all matched up properly. On certain rungs, the bottles have to balance precariously on the smaller bottle neck rungs on both sides, often causing them to fall (good thing I don't have a hard tile floor!). If the wood were not of such poor quality, I would simply reassemble the rack; I'm afraid that if I removed the screws, I would be unable to put it back together.
So just be wary of assembling furniture without directions. Not that one should ever have to.