Quick Question

I've got wort on the boil now (in fact I'm 10 minutes from adding my finishing hops) and I've got a quick question. My brother-in-law, who makes wine, gave me some Yeast Nutrient that he had left over from a previous batch. Can I use this in beer? It says that it takes 1 TSP per gallon of must and contains food grade urea and ammonium phosphate. Also, this stuff is probably several years old, could it go bad? I can't find a use by date on it... I'm doing a lager and I thought that it might be a good idea to give the yeast a bit of a head start...

Not necessary. Beer doesn't need it, as the proteins from the grains do the same thing. You would use yeast nutrient in meads or thin wines, because there are relatively fewer yeast vitamins in those.

It wouldnt hurt.