In the December 2011 issue of Brew Your Own, Brooklyn Brewmaster Garrett Oliver points out that; “… lots of homebrewers don’t begin with nearly enough of a healthy population of yeast to properly start fermentation.  And when the yeast is struggling, it gives off a lot of estery [fruity] profiles, which is a common flaw in homebrews.  I would say that the number one fault in homebrews is poor fermentation…”  The article mentions that Oliver has tasted and judged many, many homebrews.  “If you pitch your yeast and don’t see any signs of fermentation until 24 hours later, you haven’t pitched enough yeast, or it’s not as healthy as it should be.”  The article goes on to state that; “Oliver advocates making a yeast starter the day before brewing, which can easily provide double the yeast population, or harvesting yeast from a batch of homebrew.”  An inadequate pitching rate of yeast can also result in an incomplete fermentation, leaving that “malt extract” flavor finish in a batch of beer.