I just brewed a batch and have waited patiently for the fermaentation to kick in, but have not had any activity. Its been about 10 days. Any advice would be greatly appreciated.

Man, that sucks. Unfortunately, the reasons for a fermentation not getting started are many. Here's a few, and I'm sure spkrtoy will have some more advice. He's a beer brewing expert.
Bart

A. Genuine lack of fermentation can be caused by several reasons but here are the most common:
1. Not adding the yeast or the yeast is old and inactive. Add a fresh yeast packet.
2. Adding yeast over 80°F. Insure beer temperature is cool enough and add another yeast packet.
3. Temperature too cold, below 55°F can cause definite problems depending on yeasts. Warm the
brew by using a brew heater or some other method to activate the yeast (usually 65-70°F but check
yeast instructions). Brews will often stop
in the later stages of fermentation in cold conditions.
4. Not adding enough yeast. Make a starter if you are concerned about the amount of yeast.
5. Not adding enough O2 after the wort has cooled. Ensure you stir the wort or shake it to get
oxygen back into the wort so the yeast has a better start.

Thanks for the reply.
I think you may have hit on a couple problems.
I know the temp was ok. I did go up from a 5 gall. batch to a 7 gall.
I also need to know how long I can go before re-pitching the yeast?

Pitch either a rehydrated dry yeast or vial/smack pack as soon as you can.
I had one batch 4 years ago that did not start from a white labs vial, and went out of my way to get another one, and pitched it and all turned out well.

I now rely on local brewers and probrewers for yeast, and have not had a bad batch since.

pm me if you need any other info. or go to www.brewcommune.com and ask for more ideas.

gotta run,,,

I realize this is an older post, but I thought I'd throw in my 2 cents worth as well.

I just went through a similar problem with lack of fermenting, and have come up with the ireason being bad yeast. Here is how I came up with my deduction....

Last week I picked up a vial of yeast from a local homebrew store. Last Friday I made a starter batch for the yeast, and after 3 days, it still hadn't taken off. I figured the reason it didn't take off, was because I didn't have everything disinfected well enough, and contaminated the batch. This past Monday, I picked up another vial of the same yeast (from the same store), and went ahead with my normal brewing, and pitched the yeast directly this time (no starter). After 2 days, it still hadn't taken off. So yesterday, I stopped by a different store this time, and picked up another vial - I pitched it yesterday evening, and it took off overnight.

Be sure to check the date on the vial and that it's been refrigerated properly.
A good idea is to keep a packet of dry yeast around, just in case!