How much chocolate extract per 5 gallons?

[kansasbrew]

How much real chocolate extract would you guys recommend for a five gallon batch of beer? I assume that most extracts are created equal (that could be a bad guess). I've seen some say 1/2 oz and some say 2 oz. I'm assuming that it would be best to add this right at bottling? I'm calling this a Chocolate on Biscuits Ale, because it has a good amount of chocolate and biscuit malts. Who knows. What I tasted when I racked to the secondary tasted pretty good.

 

[JJL]

Never used chocolate extract specifically, but with fruit extracts you usually don't want to add more than 1.5oz at the maximum. And even that is a little overpowering for my tastes.