[84brewer]

Folks - got a beer kit for Christmas.  My wife removed the yeast smack pack when it arrived a couple of weeks ago and put it in the fridge.  I just got around to examining the goods and found that the yeast pack has already been activated.  I don't know if this happened when the kit arrived or during shipment.  I'd welcome any input on the advisability of using this yeast.

[tygo]

The yeast is probably fine.  If you have some DME you should make up a starter to get the yeast going and get some growth.  But if you're working with just a kit you may not have extra extract lying around.  In that case I'd probably just use it as is and it should be fine, especially if it's been manufactured relatively recently. 

As a general practice it's a good idea to pick up some DME to have around and make starters with every batch when using liquid yeast. 

[denny]

Your yeast will be fine.  The suggestion to make a starter is right on the money.  See mrmalty.com for instructions.  If you don't feel like making starters, it might be a good idea to stick with dry yeast.

[84brewer]

Thanks for the advice.  I normally make a starter, so it sounds like brewing as usual.  I just hadn't bumped up against this problem before.