Database: beer_factory
Question: Which root beer got the most five stars in 2012? Give the brand name of this beer.
SQL: SELECT T3.BrandName FROM rootbeer AS T1 INNER JOIN rootbeerreview AS T2 ON T1.BrandID = T2.BrandID INNER JOIN rootbeerbrand AS T3 ON T1.BrandID = T3.BrandID WHERE T2.StarRating = 5 AND strftime('%Y', T2.ReviewDate) = '2012' GROUP BY T1.BrandID ORDER BY COUNT(T2.BrandID) DESC LIMIT 1