I have the same problem. The only answer is vigilance and keeping a clean yard. I've tried pineapple, Forbid, etc, nothing works. I was debating purchasing a habanero pepper and hiding a piece in the poop to reinforce a lesson, but it turns out as we discovered during our yearly chili making that Freyja likes hot peppers, the hotter the better, so that option is out. Eventually the pup will figure out that you don't appreciate or tolerate the poop eating, and will slowly cease, but its a ton of work.
Freyja GSD- 6/21/10
Bevin (princess kitty) 08/27/07
Porsche: kitty 7/2012
Teddy (collie)- 1990-09/13/2006
Franklin (collie) 1996-06/26/2006