There is a factor at work in this recipe ratings systems that is a common bane to all rating systems which present a user with a range of choices. One commenter

There is a factor at work in this recipe ratings systems that is a common bane to all rating systems which present a user with a range of choices. One commenter (pedalpete) noted already that people gravitate high or low. But the larger issue is the number of people that will gravitate toward the current average rating. This is a natural desire to conform, and it isn't always conscious. If a user perceives that most people have rated this item X, he will naturally want to rate it X, and will even re-evaluate his judgment based upon the ratings of others. Of course, for an online-rating system with instant feedback, this gives the earliest ratings the highest weight, immediately skewing all the results which follow. But what effect does the average rating have on a person who disagrees? They will naturally tend toward the opposite extreme. They want to make their disagreement obvious. If the average rating is high, the negative rater will gravitate toward the lowest ratings, when in fact he might have gone 2 or 3 stars had he had no such prior feedback. This is a rather intractable problem, since about the only way to prevent this sort of feedback would be to hide the rating until the person has actually tried the item in question and rated it themselves. But that, of course, makes a rating system useless.