Your database isn't keeping up.
I end up having to use Untapped to rate my beers since they are never found in your app. It has an incredibly inferior rating system but the beer is always there. I've added many beers myself. But when I'm enjoying a beer with friends in a pub I'm not going to disappear into you app for 10 min. to input a beer and ignore my friends.
Can you please keep you database up to date?