I second the vinegar.
Never get scum either... I have heard good organic/grass fed meats don't cause as much scum. Are you using grocery store meat, or grass fed? I've found it to be true that when I use good meat, I get no scum on the broth.
Gel only really forms in my broths if I boil them down in a pot (about 50%) but I don't think I am doing anything wrong...
ETA: the bones are always crumbled by the end. I usually make 3 batches from the bones; the first is a lot of "soft" tissue, the second mostly minerals, and third batch I crush up and expose the marrow. I cook 24hrs for chicken bones, 48hrs per batch for beef. So chicken uses the cooker for 3 days, beef for almost a week. But as I said, I get 3 batches per half-pot of bones and it lasts about a month.
Last edited by GrokON; 05-10-2012 at 02:35 PM.
5'6" Female, 29 Years Old, 260/195/120
"Discipline is choosing between what you want NOW, and what you want MOST!"