I bottled my first batch 12 days ago using a butterfly capper and store-bought pop-off bottles (Sierra Nevada, Sam Adams and New Castle). The beer is still somewhat murky (is that ok?). I decided to open one just to see how it tasted. It tasted fine, despite apparently still having active yeast in it. However, there was practically no carbonation. I added 3/4 cup corn sugar after racking the wort. Then I bottled the beers. The seals on the bottles seem to be fine. What could possibly have caused this and is there any remedy for it?