Also, quick note. Soapy flavors can come from the yeast:
One of the things that can cause a soapy taste in beer (besides soap in cleaning the equipment!) is from the breakdown of yeast byproducts. There are fats/lipids in there, and if you remember your chemistry, saponification of lipids = soap.
In other words, if you got a bit warm during or after fermentation, the lipids could saponify, literally making soap. You could really be tasting soap from the breakdown of fatty acids.
Also check out: http://www.howtobrew.com/section4/chapter21-2.html