diff --git a/src/caosadvancedtools/cfood.py b/src/caosadvancedtools/cfood.py
index d96b47c6a085c114409d4baa34c4e8fdd0f57e81..cfed5fba69e4d9b7c64528f164ee28b37d76c020 100644
--- a/src/caosadvancedtools/cfood.py
+++ b/src/caosadvancedtools/cfood.py
@@ -76,6 +76,7 @@ class AbstractCFood(object):
         self.crawled_path = crawled_file.path
         self.match = type(self).match(crawled_file.path)
         self.to_be_updated = db.Container()
+        self.identifiables = db.Container()
 
     @staticmethod
     def get_re():
@@ -103,7 +104,7 @@ class AbstractCFood(object):
 
     def create_identifiables(self):
         """
-        must return a Container with the identifiables
+        should set the instance variable Container with the identifiables
         """
         raise NotImplementedError()
 
diff --git a/src/caosadvancedtools/crawler.py b/src/caosadvancedtools/crawler.py
index 24c974b957b8ca90eece64d8a2a1a5c8c1cf9480..334f98488443b5a8ebea0167f288a8a1aea447b7 100644
--- a/src/caosadvancedtools/crawler.py
+++ b/src/caosadvancedtools/crawler.py
@@ -78,16 +78,16 @@ class Crawler(object):
                 if Cfood.match(crawled_file.path) is not None:
                     try:
                         cfood = Cfood(crawled_file, access=self.access)
-                        identifiables = cfood.create_identifiables()
+                        cfood.create_identifiables()
 
                         if self.use_cache:
                             hashes = self.cache.update_ids_from_cache(
-                                identifiables)
+                                cfood.identifiables)
 
-                        self.find_or_insert_identifiables(identifiables)
+                        self.find_or_insert_identifiables(cfood.identifiables)
 
                         if self.use_cache:
-                            self.cache.insert_list(hashes, identifiables)
+                            self.cache.insert_list(hashes, cfood.identifiables)
 
                         cfood.update_identifiables()
                         cfood.push_identifiables_to_CaosDB()