diff --git a/README.md b/README.md
index a4669b5..01081e9 100644
--- a/README.md
+++ b/README.md
@@ -71,11 +71,14 @@ but no guarantees!
 
 ## Properties
 
-Only attributes with a property definition will be stored be CouchRest Model (as opposed
-to a normal CouchRest Document which will store everything). To help prevent confusion, 
-a property should be considered as the definition of an attribute. An attribute must be associated
-with a property, but a property may not have any attributes associated if none have been set.
+A property is the definition of an attribute, it describes what the attribute is called, how it should
+be type casted, if at all, and other options such as the default value. These replace your typical 
+`add_column` methods typically found in migrations.
 
+By default only attributes with a property definition will be stored in CouchRest Model, as opposed
+to a normal CouchRest Document which will store everything. This however can be disabled using the 
+`allow_dynamic_properties` configuration option either for all of CouchRest Model, or for specific
+models. See the configuration section for more details.
 
 In its simplest form, a property
 will only create a getter and setter passing all attribute data directly to the database. Assuming the attribute
@@ -290,6 +293,28 @@ you'd like to ensure the ID is unique between several types of document. For exa
 Pretty cool!
 
 
+## Configuration
+
+CouchRest Model supports a few configuration options. These can be set either for the whole Model code
+base or for a specific model of your chosing. To configure globally, provide something similar to the 
+following in your projects loading code:
+
+    CouchRestModel::Model::Base.configure do |config|
+      config.allow_dynamic_properties = true
+      config.model_type_key = 'couchrest-type'
+    end
+
+To set for a specific model:
+
+   class Cat < CouchRest::Model::Base
+     allow_dynamic_properties true
+   end
+
+Options currently avilable are:
+
+ * `allow_dynamic_properties` - false by default, when true properties do not need to be defined to be stored, although they will have no accessors.
+ * `model_type_key` - 'model' by default, useful for migrating from an older CouchRest ExtendedDocument when the default used to be 'couchrest-type'.
+
 
 ## Notable Issues
 
diff --git a/lib/couchrest/model/casted_model.rb b/lib/couchrest/model/casted_model.rb
index 9ef1603..8dc2f9e 100644
--- a/lib/couchrest/model/casted_model.rb
+++ b/lib/couchrest/model/casted_model.rb
@@ -4,6 +4,7 @@ module CouchRest::Model
     extend ActiveSupport::Concern
 
     included do
+      include CouchRest::Model::Configuration
       include CouchRest::Model::AttributeProtection
       include CouchRest::Model::Attributes
       include CouchRest::Model::Callbacks
diff --git a/lib/couchrest/model/configuration.rb b/lib/couchrest/model/configuration.rb
index c468a02..2dd9c88 100644
--- a/lib/couchrest/model/configuration.rb
+++ b/lib/couchrest/model/configuration.rb
@@ -9,9 +9,11 @@ module CouchRest
 
       included do
         add_config :model_type_key
+        add_config :allow_dynamic_properties
         
         configure do |config|
           config.model_type_key = 'model'
+          config.allow_dynamic_properties = false
         end
       end
 
diff --git a/lib/couchrest/model/properties.rb b/lib/couchrest/model/properties.rb
index 399673e..d6981a3 100644
--- a/lib/couchrest/model/properties.rb
+++ b/lib/couchrest/model/properties.rb
@@ -29,7 +29,7 @@ module CouchRest
 
       def write_attribute(property, value)
         prop = find_property!(property)
-        self[prop.to_s] = prop.cast(self, value)
+        self[prop.to_s] = prop.is_a?(String) ? value : prop.cast(self, value)
       end
 
       def apply_all_property_defaults
@@ -41,10 +41,11 @@ module CouchRest
       end
 
       private
+
       def find_property!(property)
         prop = property.is_a?(Property) ? property : self.class.properties.detect {|p| p.to_s == property.to_s}
-        raise ArgumentError, "Missing property definition for #{property.to_s}" unless prop
-        prop
+        raise ArgumentError, "Missing property definition for #{property.to_s}" unless allow_dynamic_properties or !prop.nil?
+        prop || property
       end
 
       module ClassMethods
diff --git a/spec/couchrest/property_spec.rb b/spec/couchrest/property_spec.rb
index 95352a9..cbcc00f 100644
--- a/spec/couchrest/property_spec.rb
+++ b/spec/couchrest/property_spec.rb
@@ -88,6 +88,13 @@ describe "Model properties" do
       expect { @card.write_attribute(:this_property_should_not_exist, 823) }.to raise_error(ArgumentError)
     end
 
+    it 'should not raise an error if the property does not exist and dynamic properties are allowed' do
+      @card.class.allow_dynamic_properties = true
+      expect { @card.write_attribute(:this_property_should_not_exist, 823) }.to_not raise_error(ArgumentError)
+      @card.class.allow_dynamic_properties = false
+    end
+
+
     it "should let you use write_attribute on readonly properties" do
       lambda {
         @card.read_only_value = "foo"