Given a long enough "rest," the alphaamylase can dismantle all the dextrins to maltose, glucose, and small, branched "limit dextrins." However, starch conversion is more effective by the faster-acting betaamylase. Beta-amylase is more selective than alpha-amylase since it breaks off two sugars at a time from the starch chain. The disaccharide it produces is maltose, the most common sugar in malt. Together, alpha- and beta-amylase are capable of converting only 60 to 80% of the available starch to fermentable sugars