karyn1, first, are you sure the stalks are bloom stalks? Sometimes my piper nigrum sends out what looks like a slender shoot that actually results in a leaf, most times though, around the base of the leaves, there is a little node that is actually an arial root. The berries seem to appear on longer, slender "stems"--the arial roots are short and "fleshy". The fruit, from what I have seen do not need intervention from human hands to pollinate--and form readily...Once the fruits are visually apparent, they seem to take quite a while to mature...
Btw, I have two piper nigrum climbing up to my second-story roof, my sister has one piper and it is snaking along the fence-line/ground and recently fruited--I "accidentally" removed/damaged my fruit stems during a rushed and bizzare move of plants...Don't ask.
Hope this helps,
Lee

They are definitely flower stalks. The "berries" have actually gotten bigger since I posted this, just very, very slowly. There's no way they'll mature before it's time to take them in. I'm going to have to cut the plants back just to move them anyway. How long does it normally take the pepper corns to ripen from the time they appear?
Thanks,
Karyn

Here's what I know. The fruits take months, yes. Months to mature to the "red" color. They can be picked and dried to turn black. Most people with the plants use them green. You just smash them up and add them to whatever you are cooking. Hope this helps.
--Lee

Thanks Lee. Hopefully I won't have to cut off all the berry stalks to get them in the GH and maybe they'll continue to ripen. It really stinks living in zone 7 when you enjoy growing zone 9 and above plants! lol
Karyn