model breaking on accepts_nested_attributes_for with no association error

I've got a `Wine` model, and a wine can have many `Varietals`. I have a `WineVarietals` model and join the Wines to Varietals through that table. When I put `accepts_nested_attributes_for :wine_varietals` in my model, I get `No association found for name`wine_varietals'. Has it been defined yet?` But I do have the association in my model. My Wine model is ``` class Wine < ActiveRecord::Base attr_accessible :name, :winery_id, :wine_varietals_attributes accepts_nested_attributes_for :wine_varietals belongs_to :winery has_many :wine_varietals #has_and_belongs_to_many :varietals, :join_table => :wine_varietals has_many :wine_photos has_many :vintages ``` I also have WineVarietal and Varietal models. If I comment out the `accepts_nested_attributes_for` line, the error goes away. I've tried different forms of pluralization `wines_varietals`, `wine_varietal` but can't seem to get rid of this error.