I have had a theory for a long time that it is the blood in the deer which causes the gamey flavor. Hunters gut the deer soon after a kill, but they don't bleed it or chill it for hours or days. It takes time to haul it from the woods, then drive home and wait until the next day before visiting the processor. It seems that the blood would be the first part of the animal to spoil.
It is my opinion that the bad reputation of venison’s “gamey” flavor comes from poor processing habits and the serving of meat that is actually rancid or at least borderline.
The key to fresh tasting meat it to get it cool and skinned as fast as possible. Leaving it hot or leaving the hide on will cause it to rot quickly and leave your meat tasting quite “pungent” (i.e.: rotten). This is important whether you plan to butcher the animal yourself or are taking it to a pro. If you leave the hide on longer than necessary or don’t cool the meat quickly, it will have a bad flavor.
http://lazyhomesteader.com/2012/08/21/the-gamey-taste-of-game-meat-part-ii/
Is it true that the gamey taste is caused by spoiled blood in the meat?
Best Answer
According to the University of Minnesota Extension (emphasis added):
So while some gaminess is simply due to the diet of the wild animals, improper dressing or treatment can be a contributing factor.