I'm a novice brewer working on my 3rd batch, which is a Brown Ale, (Sam Calagiones reciepe for A to Z Brown Ale). Unfortunately, after the final sugar addition, (Maple syrup about 3-4 days into fermentation), I had to leave on a business trip and when I returned, 8 days after the final sugar addition, my fermenting wort did not have a yeasty fermenting head on it. It just looked flat. Is this brew still good to bottle, or did I just learn an important lesson in paying attention to your brew and should dump it? Any advice would be greatly appreciated.