My brew buddy and I are struggling with efficiency when using flaked corn. The first time we used it our volume was short, could possibly be from a longer mash that he decided to do. The second time using it I came up .010 off my OG. Has anyone else run into this issue or have any advise for me? Some other info that might help to let you know: I do all grain and batch sparge in a 10 gallon cooler and have done seven other recipes that I have hit my numbers with.